Temperature sensing of power switches using modulation of driver output impedance

Abstract

Embodiments of the present disclosure generally relate to temperature detection of a power switch based on paired measurements of current and voltage. The present disclosure relates to circuits and techniques for detecting or responding to the temperature of a power switch based on paired measurements of current and voltage. A driver circuit for a power switch may be configured to perform current measurements and voltage measurements associated with temperature-dependent circuit elements, and control the power switch based at least in part on the current measurements and voltage measurements. In some examples, the current and voltage measurements may be used to determine the temperature of the power switch.

Description

Technical Field

[0001] The present disclosure relates to power switches, and more particularly to techniques and circuits for detecting temperature in power switch circuits. Background Art

[0002] Power switches are widely used in various applications to control the power delivered to the load. The power switch may include a field effect transistor (FET), a bipolar junction transistor (BJT), a gallium nitride (GaN) switch, or a possible silicon controlled rectifier (SCR). Examples of FETs may include, but are not limited to, junction field effect transistors (JFETs), metal oxide semiconductor FETs (MOSFETs), dual gate MOSFETs, insulated gate bipolar transistors (IGBTs), any other type of FET, or any combination thereof. Examples of MOSFETs may include, but are not limited to, PMOS, NMOS, DMOS, or any other type of MOSFET, or any combination thereof. Examples of BJTs may include, but are not limited to, PNP, NPN, heterojunction, or any other type of BJT, or any combination thereof.

[0003] The power switch is usually controlled via a modulation control signal, such as a pulse width modulation (PWM), a pulse frequency modulation (PFM), a pulse duration modulation, a pulse density modulation, or other types of modulation control signals. The modulation control signal can be applied to the power switch to control the on / off switching of the power switch, and thereby control the average amount of power delivered to the load by the power switch. The on / off switching of the power switch effectively divides its power delivery into discrete parts. The average value of the voltage and / or current fed to the load can be controlled by quickly turning on and off the switch. Compared with the off period, the longer the period during which the switch is turned on, the higher the total power provided to the load. In many applications, two different power switches are configured as high-side and low-side configurations, and the on / off switching of the two power switches is synchronized so as to deliver the desired power to the switch node between the high-side switch and the low-side switch.

[0004] The ability to detect temperature in a power switch is highly desirable. To this end, conventional techniques typically use external components, such as negative temperature coefficient (NTC) thermistors or semiconductor-based temperature sensors (e.g., diodes) mounted near the power switch. These external components can be electrically isolated from the power switch to simplify the measurement. Unfortunately, these conventional techniques can be inaccurate and can result in delayed responses to issues related to the temperature of the switch. For example, external components can measure the temperature of the housing of the switch or the temperature near the switch with some inherent delay, but these measurements do not always accurately indicate the temperature of the power switch itself. Summary of the invention

[0005] In general, the present disclosure describes several different techniques for detecting temperature in a power switch circuit and controlling the power switch in response to the detection of the temperature. The power switch circuit may include a power switch and a temperature-dependent circuit element (such as a temperature-dependent resistor or other circuit element that operates in a temperature-dependent manner). The temperature-dependent circuit element may be electrically coupled to at least one node of the power switch. A driver circuit for a power switch may be configured to perform useful techniques that facilitate accurate temperature detection. In addition, a variety of driver control techniques for controlling a power switch in response to temperature detection are described. The control technique may include a local control technique that may be implemented in the logic of the driver circuit, for example, to disable the power switch or adjust the transition time of the power switch. Additionally or alternatively, the control technique may include a system-level control technique that may be implemented by a controller of the driver circuit, for example, to adjust a modulated control signal delivered to the power switch.

[0006] In some examples, the present disclosure describes techniques for performing paired measurements of both current and voltage to facilitate accurate temperature determination associated with a power switch. In such examples, the current measurement and the voltage measurement can be performed based on the timing associated with the on / off switching of the power switch. For example, the current measurement and the voltage measurement can be performed at a specific time when the voltage on the power switch is stable and the power switch is not in a transition state. The measurements can be performed in pairs because both the current measurement and the voltage measurement are close to each other in time, for example, within a time window in which the temperature in the power switch is unlikely to change, or within a time window in which the voltage does not change significantly between two current measurements (or vice versa). In some examples, the current measurement and the voltage measurement can be performed within the same switching period of the power switch, but in other examples, the paired measurements can also span multiple switching periods. In other examples, the current measurement and the voltage measurement can be performed periodically at precise times within different switching periods of the power switch. The voltage measurement and the current measurement can facilitate the calculation of the input impedance of a temperature-dependent circuit element coupled to at least one node of the power switch, and this input impedance of the temperature-dependent circuit element can indicate the temperature of the power switch. In any case, the driver circuit may also be configured to control the power switch based at least in part on the current measurement and the voltage measurement. Likewise, several different control techniques are described.

[0007] In other examples, the present disclosure describes techniques in which a driver circuit is configured to modulate its output impedance and perform one or more voltage measurements while modulating the output impedance of the driver circuit. In these examples, the techniques for modulating the output impedance of the driver circuit and performing one or more voltage measurements can be performed based on timing associated with the on / off switching of the power switch, and in some cases, these techniques can be performed periodically during different switching periods of the power switch. For example, modulating the output impedance of the driver circuit and performing one or more voltage measurements can be performed at a specific time when the voltage on the power switch is stable and the power switch is not in a transition state. By modulating (e.g., adjusting or reconfiguring) the output impedance of the driver circuit when the power switch is stable, the driver circuit can be configured to calculate the input impedance of a temperature-dependent circuit element coupled to a node of the power switch based on one or more voltage measurements and a known ratio when modulating the output impedance of the driver circuit. The input impedance of the temperature-dependent circuit can indicate the temperature of the power switch. In any case, the driver circuit can also be configured to control the power switch based at least in part on one or more voltage measurements. Similarly, several different control techniques are also described.

[0008] In one example, the present disclosure describes a circuit including a driver circuit configured to control a power switch circuit including a power switch and a temperature-dependent circuit element electrically coupled to at least one node of the power switch. The driver circuit is configured to deliver a modulated signal to a control node of the power switch to control on / off switching of the power switch. In addition, the driver circuit is configured to perform current measurements and voltage measurements associated with the temperature-dependent circuit element, and to control the power switch based at least in part on the current measurements and voltage measurements. The current measurements and voltage measurements are performed based on timing associated with on / off switching of the power switch.

[0009] In another example, the present disclosure describes a method of controlling a power switch circuit, the power switch circuit including a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element electrically coupled to at least one node of the power switch. The method includes delivering a modulated signal to a control node of the power switch to control on / off switching of the power switch, performing a current measurement associated with the temperature-dependent circuit element, performing a voltage measurement associated with the temperature-dependent circuit element, and controlling the power switch based at least in part on the current measurement and the voltage measurement.

[0010] In another example, a circuit arrangement includes a power switch circuit and a driver circuit, the power switch circuit including a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element electrically coupled to at least one node of the power switch, the driver circuit configured to deliver a modulated signal to a control node of the power switch to control on / off switching of the power switch. The driver circuit is configured to perform current measurements and voltage measurements associated with the temperature-dependent circuit element and control the power switch based at least in part on the current measurements and voltage measurements. The current measurements and voltage measurements are performed based on timing associated with on / off switching of the power switch.

[0011] In another example, the present disclosure describes a circuit configured to control a power switch circuit, the power switch circuit including a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element electrically coupled to at least one node of the power switch. The circuit includes a driver circuit configured to be coupled to a power circuit, wherein the driver circuit is configured to deliver a modulation signal to a control node of the power switch to control on / off switching of the power switch. The driver circuit is also configured to modulate an output impedance of the driver circuit at the control node, perform one or more voltage measurements while modulating the output impedance of the driver circuit, and control the power switch based at least in part on the one or more voltage measurements.

[0012] In another example, the present disclosure describes a method of controlling a power switch circuit, the power switch circuit including a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element electrically coupled to at least one node of the power switch. The method includes delivering a modulation signal to a control node of the power switch to control on / off switching of the power switch, modulating an output impedance of a driver circuit at the control node, performing one or more voltage measurements while modulating the output impedance of the driver circuit, and controlling the power switch based at least in part on the one or more voltage measurements.

[0013] In another example, a circuit arrangement includes a power switch circuit and a driver circuit, the power switch circuit including a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch, the driver circuit being configured to be coupled to a power supply circuit. The driver circuit is configured to deliver a modulation signal to a control node of the power switch to control on / off switching of the power switch, and the driver circuit is further configured to modulate an output impedance of the driver circuit at the control node, perform one or more voltage measurements while modulating the output impedance of the driver circuit, and control the power switch based at least in part on the one or more voltage measurements.

[0014] The details of these and other examples are set forth in the drawings and the description that follows. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a block diagram of an example circuit arrangement including a power switch circuit and a driver circuit configured to perform one or more of the techniques described herein;

[0016] Figure 2 is an example circuit diagram of a power switch circuit including a power switch and a temperature dependent resistor coupled to at least one node of the power switch;

[0017] Figure 3 is a block diagram of an example circuit arrangement including a power switch circuit and a driver circuit configured to perform one or more of the techniques described herein;

[0018] Figure 4 is a block diagram of an example circuit arrangement including a driver circuit having a high ohmic path and a low ohmic path that may be used to modulate the output impedance of the driver circuit according to one or more techniques of this disclosure;

[0019] Figure 5 is another block diagram of an example circuit device capable of performing paired voltage and current measurements;

[0020] Figure 6 is another block diagram of a circuit arrangement consistent with the techniques of the present disclosure and including both a low-side power switch and a low-side driver circuit and a high-side power switch and a high-side driver circuit;

[0021] Figure 7 is a block diagram of an example circuit arrangement including a driver circuit capable of modulating its output impedance;

[0022] Figure 8 is a block diagram of a circuit arrangement including both a low-side power switch and a low-side driver circuit and a high-side power switch and a high-side driver circuit, wherein the driver circuit can be modulated to define a high output impedance;

[0023] Fig. 9 is a timing diagram illustrating example timing of temperature sensing associated with a high-side power switch and a low-side power switch;

[0024] Fig.10 and 11 is a flow chart of a temperature sensing and control technique using paired voltage and current measurements consistent with the present disclosure; and

[0025] Fig.12 and 13 is a flow chart of a temperature sensing and control technique using modulation of driver output impedance and one or more voltage measurements consistent with the present disclosure. DETAILED DESCRIPTION

[0026] Figure 1 1 is a block diagram of an example circuit arrangement 100 including a power switch circuit 104 and a driver circuit 102 with temperature-dependent control. The power switch circuit 104 may include a power switch 108 and a temperature-dependent circuit element 106 coupled to at least one node of the power switch 108. For example, the temperature-dependent circuit element 106 may include a temperature-dependent resistor coupled between a control node and an output node of the power switch 108. The driver circuit 102 is an example of a driver circuit configured to perform one or more of the techniques described herein. The present disclosure describes several different techniques for detecting temperature in a power switch circuit and controlling the power switch in response to the detection of the temperature.

[0027] In some examples, the driver circuit 102 can be configured to perform paired measurements of both current and voltage to facilitate accurate temperature determination associated with the temperature-dependent circuit element 106, thereby providing an accurate measurement of the temperature of the power switch circuit 104. In such an example, the driver circuit 102 can be configured to perform current measurements and voltage measurements based on timing associated with the on / off switching of the power switch 108. For example, the current measurement and the voltage measurement can be performed at a specific time when the voltage across the power switch 108 is stable and the power switch 108 is not in a transition state. The driver circuit 102 can perform so-called "paired measurements" of current and voltage because the current measurement and the voltage measurement are close to each other in time, for example, within a time window in which the temperature in the power switch circuit 104 is unlikely to change, or within a time window in which the voltage does not change significantly between two current measurements (or vice versa). In some examples, the driver circuit 102 can be configured to perform the current measurement and the voltage measurement within the same switching period of the power switch 108, but in other examples, the paired measurements can also span multiple switching periods. Furthermore, in some cases, the paired measurements may be repeated over consecutive switching periods of the power switch, e.g., each period or every “Nth” period, where N is a positive integer. In other cases, the paired measurements may be performed in response to a trigger or command from a control circuit. In any case, the voltage measurement and the current measurement may facilitate the calculation of the input impedance of the temperature-dependent circuit element 106 coupled to at least one node of the power switch 108. This input impedance of the temperature-dependent circuit element 106 may indicate the temperature of the power switch 108. In various examples, the driver circuit 102 may also be configured to control the power switch 108 based at least in part on the current measurement and the voltage measurement. Likewise, several different control techniques are described below.

[0028] In other examples, the driver circuit 102 may be configured to modulate its output impedance and perform one or more voltage measurements while modulating the output impedance of the driver circuit 102. In these examples, modulating the output impedance of the driver circuit 102 and performing the one or more voltage measurements may be performed based on a timing associated with the on / off switching of the power switch 108. For example, modulating the output impedance of the driver circuit 102 and performing the one or more voltage measurements may be performed at a specific time when the voltage across the power switch 108 is stable and the power switch 108 is not in a transition state. Furthermore, in some cases, modulating the output impedance of the driver circuit 102 and performing the one or more voltage measurements may be repeated within consecutive switching periods of the power switch, e.g., every period or every “Nth” period, where N is a positive integer. In other cases, modulating the output impedance of the driver circuit 102 and performing the one or more voltage measurements may be performed in response to a trigger or command from a control circuit. In any case, by modulating (e.g., adjusting or reconfiguring) the output impedance of the driver circuit 102 when the power switch 108 is stable, the driver circuit 102 can calculate the input impedance of the temperature-dependent circuit element 106 coupled to the node of the power switch 108 based on one or more voltage measurements and the known ratio when modulating the output impedance of the driver circuit 102. The input impedance of the temperature-dependent circuit element 106 can be indicative of the temperature, thereby providing a measure of the temperature of the power switch circuit 104. In any case, the driver circuit 102 can also be configured to control the power switch 108 based at least in part on the one or more voltage measurements. Likewise, several different control techniques are described below.

[0029] Figure 2 2 is an example circuit diagram of a power switch circuit 204 including a power switch 205 and a temperature-dependent resistor 206 coupled to at least one node of the power switch 205. The power switch 205 may include any of a variety of transistors for power delivery, such as a field effect transistor (FET), a bipolar junction transistor (BJT), a gallium nitride (GaN) switch, or a silicon controlled rectifier (SCR). Examples of FETs may include, but are not limited to, junction field effect transistors (JFETs), metal oxide semiconductor FETs (MOSFETs), dual-gate MOSFETs, insulated gate bipolar transistors (IGBTs), any other type of FET, or any combination thereof. Examples of MOSFETs may include, but are not limited to, PMOS, NMOS, DMOS, or any other type of MOSFET, or any combination thereof. Examples of BJTs may include, but are not limited to, PNP, NPN, heterojunction, or any other type of BJT, or any combination thereof.

[0030] The power control circuit 204 may include a control terminal 201 for providing a modulated control signal for on / off switching of a power switch 205. Terminals 202 and 203 are labeled as load terminals, as long as the load can be attached to terminal 202 or terminal 203, depending on the use and configuration of the power switch circuit 204 within a larger system. Depending on the configuration and location of the load, current flows from terminal 202 through the power switch 205 to terminal 203, or from terminal 203 through the power switch 205 to terminal 202. The modulated control signal from the driver circuit may be delivered to the control terminal 201 to control the on / off switching of the power switch 205, thereby delivering current to the load. In the example of a MOSFET, the control terminal 201 may include a gate, the load terminal 202 may include a drain, and the load terminal 203 may include a source. In the example of a BJT, the control terminal 201 may include a base, the load terminal 202 may include a collector, and the load terminal 203 may include an emitter. In some cases, an additional gate resistor 208 (or base resistor for example of a BGT) may be located between the control terminal 201 and the control node of the power switch 205. The internal connection between the control terminal and the semiconductor region also forms a series resistance.

[0031] like Figure 2 As shown, the power switch circuit 204 includes a temperature-dependent circuit element (such as a temperature-dependent resistor 206 or other temperature-dependent element) electrically coupled to at least one node of the power switch 205. For example, the temperature-dependent resistor 206 can be located between the control node of the power switch 205 and the load node of the power switch 205 to provide a current path in parallel with the current path from the terminal 202 to the terminal 203 (or vice versa) through the power switch 205. According to the present disclosure, the driver circuit ( Figure 2 2 (not shown) can be configured to perform useful techniques to facilitate accurate temperature detection of temperature-dependent circuit element 206, which can provide an accurate indication of the temperature of power switch circuit 204. In addition, various driver control techniques for controlling the power switch in response to temperature detection are described.

[0032] Figure 3 is a block diagram of an example circuit arrangement 300 including a power switch circuit 304 and a driver circuit 302 configured to perform one or more of the techniques described herein. A driver power supply 315 may be configured to provide necessary power to the driver circuit 302 .

[0033] The driver circuit 302 may be configured to control the power switch circuit 304. The power switch circuit 304 includes a power switch 308 and a temperature-dependent circuit element 306 electrically coupled to at least one node of the power switch 302. Figure 2 Shows that it can be Figure 3 304 corresponds to an example of a power switch circuit 204, although other configurations or circuit elements may also be used. Generally, the driver circuit 302 may include a driver 312, which is configured to deliver a modulation signal to a control node of the power switch 308 to control the on / off switching of the power switch 308. In addition, the driver circuit 302 includes a current sensing unit 314 configured to perform current measurements and a voltage sensing unit 316 configured to perform voltage measurements. The current measurement and voltage measurement performed by the current sensing unit 314 and the voltage sensing unit 306 may include measurements associated with temperature-dependent circuit elements, and the measurements may be paired because the current measurement and the voltage measurement are close in time, for example, within a time window in which the temperature in the power switch circuit 304 is unlikely to change, or within a time window in which the voltage does not change significantly between two current measurements (or vice versa). In some examples, the current measurement and the voltage measurement are performed by the current sensing unit 314 and the voltage sensing unit 306 within the same switching period of the power switch 308, but in other examples, the paired measurements may also span multiple switching periods. Thus, sometimes, paired measurements can be made based on extrapolation or known behavior of the circuit, even if the measurements span two or more switching periods. Also, in some cases, paired measurements can be made periodically, for example, every switching period or every “Nth” switching period, where N is a positive integer. Also, in some cases, paired measurements can be made in response to a request from a controller ( Figure 3 304 ) to a trigger or command to the driver circuit 302. In any case, based on the voltage measurement and the current measurement, the driver circuit 312 can be configured to calculate the input impedance of the temperature-dependent circuit element 306, and the input impedance of the temperature-dependent circuit element 306 can indicate the temperature of the power switch circuit 304. In addition, the driver circuit 312 can also be configured to control the power switch 308 based at least in part on the current measurement and the voltage measurement. In some cases, the driver circuit 312 can control or adjust the operation of the power switch based on the calculated impedance, and in some cases, additional steps can be performed by mapping the calculated impedance to the actual temperature, in which case the calculated temperature can be used in the control scheme. Either case can result in the desired control of the power switch 308 that responds to or adapts to the temperature.

[0034] In some examples, the current measurement and the voltage measurement performed by the current sensing unit 314 and the voltage sensing unit 316 are performed based on the timing associated with the on / off switching of the power switch controlled by the driver 312. For example, the current measurement and the voltage measurement performed by the current sensing unit 314 and the voltage sensing unit 316 may be performed one or more times when the voltage on the power switch 308 is stable and the power switch 308 is not in a transition state. In some examples, the driver 312 may determine that the voltage on the power switch 308 is stable based on determining that the driver power supply voltage from the power supply 315 is stable. For example, the current measurement and the voltage measurement may be performed when the power switch 308 is turned on, stable, and not in a transition state. Alternatively, the current measurement and the voltage measurement performed by the current sensing unit 314 and the voltage sensing unit 316 may be performed when the power switch 308 is turned off, stable, and not in a transition state, in which case the driver 312 may be configured to apply a negative voltage to the control node of the power switch 308 during the current measurement and the voltage measurement. In some examples, current sensing unit 314 and voltage sensing unit 316 can be configured to refrain from sensing when power switch 308 is unstable or operating in a transition state.

[0035] As described above, the current measurement and voltage measurement performed by the current sensing unit 314 and the voltage sensing unit 316 may include paired measurements. In some cases, the circuit device 300 may include a memory or storage device configured to store paired measurements. In some examples, the voltage measurement may include, for example, a measurement of a voltage provided to the driver circuit 302 from the power supply 315 for driving the power switch 308. In other examples, the voltage measurement may include a measurement of a voltage drop across the temperature-dependent circuit element 306. As an example, the current sensing unit 314 may use one or more shunt resistors or current mirror circuits to perform current measurements.

[0036] In some examples, if the temperature-dependent circuit element 306 is connected to the control node, the voltage sensing unit 316 can be used to measure the voltage of the control node of the power switch 308. In some examples, if the voltage drop across the unit 312 between the output of the power unit 315 and the control node of the power switch is known or close to zero, the voltage sensing unit 316 can be used to measure the voltage of the power unit 315. In other examples, if the other terminal of the element 306 is connected to the load terminal of the power switch 308, the voltage sensing unit 316 can be used to measure the voltage at the terminal of the temperature-dependent circuit element 306.

[0037] A variety of driver control techniques can be used to control the power switch 308 in response to temperature detection. In some examples, the driver circuit 302 includes logic configured to control the power switch 308 in response to current measurements and voltage measurements indicative of the temperature of the power switch. Figure 3 ). For example, the driver 312 can be configured to respond to one or more temperature-related changes in the operation of the power switch circuit. For example, the logic can be configured to adjust the transition speed of the power switch 308 in response to current measurements and voltage measurements indicating the temperature of the power switch 308. As another example, the logic can be configured to disable the power switch 308 in response to current measurements and voltage measurements indicating the temperature of the power switch 308, which can provide device protection. Disabling the power switch 308 can include turning off the power switch, and in some cases, disabling the power switch 308 can also include preventing the power switch 308 from turning on. As described above, in some cases, the circuit response can occur based on a calculation of an impedance (e.g., an input impedance of the temperature-dependent circuit element 306) that indicates the temperature of the power switch 308. Therefore, in some examples, in the logic ( Figure 3 ) may be configured to control the power switch 308 in response to a calculation of an impedance indicative of a temperature of the power switch 308, wherein the calculation of the impedance is based on a current measurement and a voltage measurement.

[0038] In some examples, the current sensing unit 314 and the voltage sensing unit 316 of the driver circuit 302 can be configured to perform current measurement and voltage measurement within the same switching period of the power switch 308. In addition, in some examples, the current sensing unit 314 and the voltage sensing unit 316 of the driver circuit 302 can be configured to perform at least one of the current measurement or the voltage measurement multiple times within each switching period of the power switch. In other cases, the current sensing unit 314 and the voltage sensing unit 316 of the driver circuit 302 can be configured to perform at least one of the current measurement or the voltage measurement multiple times within consecutive switching periods. In addition, in some cases, the current sensing unit 314 and the voltage sensing unit 316 of the driver circuit 302 can be configured to perform at least one of the current measurement or the voltage measurement in response to a command or trigger from a controller (not shown). The driver circuit 302 can be configured to pair and store paired measurements of current and voltage for determining temperature. In some examples, the current sensing unit 314 and the voltage sensing unit 316 of the driver circuit 302 can be configured to perform at least one current measurement and a plurality of voltage measurements during the same switching period of the power switch 308 .

[0039] The power switch 308 may include a so-called "high-side" power switch. In some configurations, the high-side power switch is connected to a so-called "low-side" power switch and a load is coupled to a switch node between the high-side power switch and the low-side power switch. The technology disclosed herein may be used for temperature detection and control of a high-side power switch, a low-side power switch, or both a high-side power switch and a low-side power switch. In another example, a control unit (e.g., a digital control unit) may be used to control the driver 312 and may deliver commands or triggers to initiate voltage and current measurements for temperature detection. In addition, the present disclosure describes configurable parameters that may be used to configure the driver circuit 302, a control unit, or other units. Additional details of other aspects of exemplary control units, configurability, and temperature detection techniques are described in more detail below.

[0040] As described above, temperature-dependent circuit element 306 may include a temperature-dependent resistor, but other types of temperature-dependent circuit elements may also be used in accordance with the present disclosure. In some cases, temperature-dependent circuit element 306 is electrically coupled to a control node of power switch 308 and a load node of power switch 308 (e.g., Figure 2 However, in other examples, the temperature-dependent circuit element 306 may be electrically coupled to a dedicated sense node (which may include a dedicated sense pin) associated with the power switch circuit 304 and a load node of the power switch 308.

[0041] Figure 4 4 is a block diagram of an example circuit device 400 including a driver circuit 402 including a driver 412 including a high-ohmic path 418 and a low-ohmic path 417. For this example, the driver circuit 402 can be used to modulate the output impedance of the driver 412 to facilitate accurate temperature measurement based on a known ratio between voltages associated with the high-ohmic path 418, for example, by referencing a reference measurement at a given temperature. As an example, if the impedance of the high-ohmic path is known (e.g., by trimming or per construction), the impedance of the temperature-dependent circuit element 406 can be calculated by measuring the voltage at two terminals of the high-ohmic path. In some examples, the temperature of the temperature-dependent circuit element can be calculated based on the ratio between the measured voltages associated with the high-ohmic path 418 and the known ratio at a known temperature.

[0042] As an example, the ratio between the voltage at the gate driver terminal connected to the control node of the power switch and the voltage at the gate driver terminal connected to the gate driver power supply can be used as a baseline for temperature calculation. In this case, the path through the gate driver can be configured as an ohmic path, which forms an ohmic voltage divider with the impedance of the temperature-dependent circuit element. In one implementation, both voltages can be measured with one or more analog-to-digital converters (ADCs) referenced to at least one reference voltage, and the ratio can be calculated based on the conversion result. In another implementation, the voltage at the power input terminal of the gate driver can be used as a reference for the measurement of the voltage at the gate driver terminal connected to the control node of the power switch. This technique can be called ratiometric measurement, and the ratio between the two voltages is provided by a single AD conversion. In this case, the result is always "paired" because the ADC takes into account both voltages at the same time. If these measurements are made in the teaching phase, such as on a test device during production testing at different temperatures, the conversion result can be directly used as the input of the LUT without knowing or trimming the value of the high ohmic path. The low-ohmic path can be used to control the control node of the power switch during the transition between the switching states of the power switch, and control the transition itself (e.g., switching speed). The low-ohmic path can be constructed in a manner to ensure that the voltage measurement on the low-ohmic path does not deliver a measurement result that is accurate enough for temperature calculations (e.g., the impedance of the low-ohmic path << the temperature-dependent circuit element). If the voltage on the load terminal of the power switch is stable and not in a transition state, the driver output impedance can be changed from the low-ohmic path to the high-ohmic path to make a more accurate voltage measurement because the voltage drop on the high-ohmic path is greater than the voltage drop on the low-ohmic path (in a stable state).

[0043] The driver circuit 402 may be configured to control a power switch circuit 404, which includes a power switch 408 and a temperature-dependent circuit element 406, which is electrically coupled to at least one node of the power switch 408. The driver circuit 402 may be configured to be coupled to a power supply circuit 415, and the driver circuit 402 may be configured to deliver a modulation signal to a control node of the power switch 408 to control the on / off switching of the power switch 408. In addition, the driver circuit 402 may also be configured to modulate the output impedance of the driver circuit 412 at the control node of the power switch 402. The voltage sensing unit 416 of the driver circuit 402 may be configured to perform one or more voltage measurements while the driver circuit 412 modulates the output impedance, and the driver circuit 402 may control the power switch 408 based at least in part on the one or more voltage measurements. To modulate the output impedance of the driver circuit 402 at the control node of the power switch 408, the driver 412 may include both a low ohmic path 417 from the power circuit 415 to the control node of the power switch 408, and a high ohmic path 418 from the power circuit 415 to the control node. One or more switches 413A and 413B may be configured to switch the driver 412 between the low ohmic path and the high ohmic path. Thus, to modulate its output impedance, the driver circuit 412 may be configured to switch the driver 412 from the low ohmic path 417 to the high ohmic path 418, and while the driver 412 is configured to define the high ohmic path, the driver circuit 402 may be configured to perform one or more voltage measurements.

[0044] One or more voltage measurements can be performed at the output of the driver circuit 402 and can be used to calculate the input impedance of the temperature-dependent circuit element 406. As an example, both the low-ohm path and the high-ohm path can be constructed by a path element (such as a transistor) that can be configured to change its conductivity. In this case, the description of the high-ohm path relates to a first operating condition of the configurable path element, and the low-ohm path relates to a second operating condition of the same path element. In some examples, the low-ohm path can be operated as a current source, and the high-ohm path can be operated as a resistive element. In some examples, the low-ohm path element can be constructed with a component different from that of the high-ohm path. Two switches 413A and 413B refer to the activation of the low-ohm path or the high-ohm path. In one implementation, these switches can be used to select the operating conditions that lead to the low-ohm path or the high-ohm path. In another implementation, these switches can be part of the low-ohm path and / or the high-ohm path.

[0045] In some cases, the voltage sensing unit 416 may perform one or more voltage measurements at the output of the driver 412, and the driver circuit 402 may use the voltage measurements and a known ratio associated with the high-ohmic path 418 to determine the input impedance of the temperature-dependent circuit element 406. In this manner, the driver circuit 402 may be configured to calculate the input impedance of the temperature-dependent circuit element 406 based on the one or more voltage measurements of the voltage sensing unit 416 and the known ratio when modulating the output impedance of the driver circuit. The low-ohmic path 417 may include a normal electrical path used when delivering a control signal to the power switch 408, while the high-ohmic path 418 may include an alternative path with a high resistance that is modulated to the control node of the power switch 408 when the power switch is stable to facilitate temperature determination based on the measured voltage and the known ohmic ratio defined by the high-ohmic path 418. A network of one or more resistors may be used to define the high-ohmic path 418, but other components may also be used to modulate the output impedance of the driver 412. For example, other components that may be used for such output impedance modulation may include one or more analog-to-digital converters, one or more switches, or other electrical elements or components.

[0046] The driver circuit 412 can be configured to switch from the low ohmic path 412 to the high ohmic path 418 and cause the voltage sensing unit 416 to perform one or more voltage measurements based on the timing associated with the on / off switching of the power switch. In some examples, when the power switch 408 is stable and the power switch 408 is not in a transition state, the driver circuit 412 is configured to modulate from the low ohmic path 417 to the high ohmic path 418 and cause the voltage sensing unit 416 to perform one or more voltage measurements. In some examples, the driver 412 can determine that the voltage on the power switch 408 is stable based on determining that the driver power supply voltage from the power supply 415 is stable. In some cases, the one or more voltage measurements performed by the voltage sensing unit 416 are performed when the power switch 408 is turned on, stable, and not in a transition state. Alternatively, the one or more voltage measurements performed by the voltage sensing unit 416 can be performed when the power switch is turned off, in which case the driver circuit 402 can be configured to apply a negative voltage to the control node of the power switch 408 during the one or more voltage measurements. In some examples, voltage sensing unit 416 can be configured to refrain from sensing when power switch 408 is unstable or operating in a transition state.

[0047] In some cases, the driver circuit 402 may be configured to modulate from a first configuration defining a low ohmic path 417 to a second configuration defining a high ohmic path 418 and then perform one or more voltage measurements multiple times within a switching period of the power switch. In other cases, the driver circuit 402 may be configured to modulate from the low ohmic path 417 to the high ohmic path 418 and perform one or more voltage measurements multiple times within consecutive switching periods of the power switch 408 or periodically at every Nth period of the power switch 408, where N is a positive integer. In addition, in other cases, the driver circuit 402 may be configured to modulate from the low ohmic path 417 to the high ohmic path 418 and perform one or more voltage measurements in response to a control unit ( Figure 4 The voltage sensing unit 416 may be configured to perform one or more voltage measurements in response to a command or trigger of (not shown in FIG. 4 ). In some cases, the voltage sensing unit 416 may include an analog-to-digital converter (ADC) or an analog amplifier or an analog comparator.

[0048] Similar to Figure 3 For example, Figure 4 In some examples, in response to temperature detection, a variety of driver control techniques can be used to control power switch 408. In some examples, driver circuit 402 includes logic configured to control power switch 408 in response to one or more voltage measurements and a known ratio between voltages or a known impedance of a high-ohmic path indicative of a temperature of the power switch. Figure 4 ). For example, the driver 412 can be configured to respond to one or more temperature-related changes in the operation of the power switch circuit 404. For example, the logic can be configured to adjust the transition speed of the power switch 408 in response to one or more voltage measurements (and known ratios or impedances) indicating the temperature of the power switch 408. As another example, the logic can be configured to disable the power switch 408 in response to one or more voltage measurements (and known ratios or impedances) indicating the temperature of the power switch 408, which can provide device protection. Disabling the power switch 408 can include turning off the power switch, and in some cases, disabling the power switch 408 can also include preventing the power switch 408 from turning on. As described above, in some cases, the circuit response can occur based on a calculation of an impedance (e.g., an input impedance of the temperature-dependent circuit element 406) or a voltage at a terminal of a high-ohmic path that indicates the temperature of the power switch 408. Thus, in some examples, the logic ( Figure 4 ) may be configured to control the power switch 408 in response to a calculation of an impedance indicative of a temperature of the power switch 408, wherein the calculation of the impedance is based on a voltage measurement and a known ratio associated with the high-ohmic path 418.

[0049] In some examples, the voltage sensing unit 416 of the driver circuit 402 can be configured to perform several voltage measurements within the same switching period of the power switch 408. In addition, in some examples, the voltage sensing unit 416 of the driver circuit 402 can be configured to perform voltage measurements multiple times within each switching period of the power switch 408. In other cases, the voltage sensing unit 416 of the driver circuit 402 can be configured to perform one or more voltage measurements multiple times within consecutive switching periods (e.g., each period or every Nth period). In addition, in some cases, the voltage sensing unit 416 of the driver circuit 402 can be configured to respond to the control unit ( Figure 4 ) to perform one or more voltage measurements.

[0050] Similar to Figure 3 For example, Figure 4 In the example of, power switch 408 may include a so-called "high side" power switch. In some configurations, the high side power switch is connected to a so-called "low side" power switch, and the load is coupled to a switch node between the high side power switch and the low side power switch. The technology disclosed herein can be used for temperature detection and control of a high side power switch, a low side power switch, or both a high side power switch and a low side power switch. In another example, a control unit (e.g., a digital control unit) can be used to control driver 412, and may deliver commands or triggers to initiate output impedance modulation and voltage measurement for temperature detection. In addition, the present disclosure describes configurable parameters that can be used to configure driver circuit 402, control unit, or other units. Additional details of other aspects of exemplary control units, configurability, and temperature detection techniques are described in more detail below.

[0051] Temperature-dependent circuit element 406 may include a temperature-dependent resistor, but other types of temperature-dependent circuit elements may also be used in accordance with the present disclosure. In some cases, temperature-dependent circuit element 406 is electrically coupled to a control node of power switch 408 and a load node of power switch 408 (e.g., Figure 2 , coupled between a node at Gint and a node at E). However, in other examples, temperature-dependent circuit element 406 may be electrically coupled to a dedicated sense node associated with power switch circuit 404 and a load node of power switch 408.

[0052] Figure 5 5 is another block diagram of an example circuit arrangement capable of performing paired voltage and current measurements. Circuit arrangement 500 includes a power switch circuit 504, which may be similar to Figure 2The circuit arrangement 500 also includes a control unit 522, which may include a digital processing unit, such as a microprocessor, an ASIC, an FPGA, a CPLD, or a microcontroller. In addition, the circuit arrangement 500 includes a gate driver 512, a gate driver power supply 520, a synchronization unit 524, a decision unit 526, a temperature function unit 516, and a voltage and current sensing unit 514. In some examples, the units 512, 520, 524, 526, 516, and 514 may be part of a gate driver circuit, although one or more of these units may also be implemented as a separate circuit or part of the control unit 522.

[0053] The gate driver 512 may be configured to control a power switch within the power switch circuit 504, which may also include a temperature-dependent circuit element electrically coupled to at least one node of the power switch. Figure 2 Additional details are provided regarding the power switch circuit 204, which may be similar to the power switch circuit 504. The gate driver 512 is configured to deliver a modulated signal to a control node of a power switch within the power switch circuit 504 to control the on / off switching of the power switch. The gate driver power supply 520 may provide the necessary power for the operation of the gate driver 512 and the control node for controlling the power switch. The voltage and current sensing unit 514 is configured to perform current measurements and voltage measurements associated with temperature-dependent circuit elements within the power switch circuit 504. As described herein, these voltage measurements and current measurements may be paired and timed according to switching periods associated with the on / off switching of the power switch within the power switch circuit 504.

[0054] In some examples, the current measurement and the voltage measurement performed by the voltage and current sensing unit 514 are performed within the same switching period of the power switch within the power switch circuit 504, but in other examples, the paired measurements can also span multiple switching periods. In addition, in some cases, the paired measurements can be performed by the voltage and current sensing unit 514 periodically, for example, every switching period or every "Nth" switching period, where N is a positive integer. In addition, in some cases, the paired measurements can be performed in response to a trigger or command from the control unit 522. In some examples, a filter structure can be used to filter the results of several paired measurements to reduce the noise impact or distortion of a single measurement.

[0055] The synchronization unit 524 may deliver a measurement trigger signal to the voltage and sense unit 514 to coordinate the timing of the paired measurements so that the current measurement and the voltage measurement are performed based on the timing associated with the on / off switching of the power switch. The synchronization unit 524 may receive a signal (or a mirror image of the signal) associated with the PWM control signal from the control unit 522, which is also delivered to the gate driver 512. In this way, the synchronization unit 524 may identify the time when the power switch within the power switch circuit 504 is stable to trigger the paired measurements performed by the voltage and sense unit 514. The temperature function unit 516 may determine the temperature associated with the power switch circuit 504 based on the paired current measurement and voltage measurement to essentially apply Ohm's law to calculate the impedance of the temperature-dependent circuit element based on the measured voltage and current on and through the temperature-dependent circuit element. In some cases, the calculated impedance itself may be used as an indicator of temperature, while in other cases, the calculated impedance may be mapped to temperature, such as via a mathematical equation or a lookup table (LUT). In any case, temperature function unit 516 may provide a temperature indication to decision unit 526 .

[0056] The decision unit 526 can be configured to cause a driver-level or system-level reaction to the temperature, or both a driver-level and system-level reaction. The driver-level reaction can include an immediate driver response to the temperature, for example, via logic within the gate driver 512. Such a driver-level reaction can include disabling a power switch within the power switch circuit 504 in response to the temperature, or possibly adjusting (increasing or decreasing) a transition time associated with the power switch in response to the measured temperature, or changing the timing and / or level of a current or voltage to charge or discharge a control node of the power switch. In some cases, disabling the power switch can include turning off the power switch, and in some cases, disabling the power switch can include disabling the ability to turn the power switch back on.

[0057] As described above, the decision unit 526 can also be configured to cause a system-level reaction to temperature. The system-level reaction can include adjusting the PWM control signal based on the measured temperature, such as adjusting the duty cycle. The driver-level reaction may be more sensitive to temperature changes, thereby providing circuit protection based on the adjustment of the temperature or operating conditions of the power switch. The system-level reaction helps improve the operation of the system at different temperatures.

[0058] The current measurement and voltage measurement performed by the voltage and current sensing unit 514 can be based on the timing associated with the on / off switching of the power switch within the power switch circuit 504, the measurement being controlled by the PWM signal defined by the control unit 522 and delivered by the gate driver 512 to power the switch circuit 504. As described herein, the current measurement and the voltage measurement can be performed at specific times when the voltage across the power switch within the power switch circuit 504 is stable and the power switch is not in a transition state. In addition, the voltage and current sensing unit 514 can refrain from sensing at other times when the power switch within the power switch circuit 504 is unstable or operating in a transition state. Likewise, the voltage measurement and the current measurement can be so-called "paired measurements" of current and voltage because the current measurement and the voltage measurement are close to each other in time, for example, within a time window where the temperature in the power switch circuit 504 is unlikely to change, or within a time window where the voltage does not change significantly between two current measurements (or vice versa). In some examples, the voltage and current sensing unit 514 can be configured to perform current measurements and voltage measurements within the same switching period of the power switch within the power switch circuit 504, but in other examples, the paired measurements can also span multiple switching periods. In addition, in some cases, the paired measurements can be repeated within consecutive switching periods of the power switch, for example, every period or every "Nth" period, where N is a positive integer. In other cases, the paired measurements can be performed in response to a trigger or command from the control unit 522. In some cases, the user can cause the control unit 522 to initiate a trigger to provide the user with the ability to measure the temperature of the power switch circuit 504 when needed.

[0059] Figure 6 is an example of another block diagram consistent with the techniques of this disclosure and including both a low-side power switch circuit and a low-side gate driver circuit and a high-side power switch and a high-side driver circuit. Figure 6 Examples include a first power switch circuit 604 and a second power switch circuit 654, which can be referred to as a high-side and a low-side power switch circuit. A switch node between the first power switch circuit 604 and the second power switch circuit 654 delivers power to the load based on the on / off switching of the power switches within the circuits 604 and 654.

[0060] The first gate driver 612 delivers a modulation control signal to the high-side power switch in the power switch circuit 604, and the second gate driver 642 delivers a modulation control signal to the low-side power switch in the power switch circuit 654. The control unit 622 can deliver PWM commands to the gate drivers 612 and 642 to coordinate the on / off switching of the high-side and low-side power switches. External gate resistors 621 and 641 can be included between the control terminals of the power switch circuits 604 and 654 and the gate drivers 612 and 642, respectively. For example, these external gate resistors 621 and 641 can define a resistance less than 10 ohms. The gate driver power supplies 620 and 640 can provide the power required for operating the gate drivers 612 and 642.

[0061] On the high side, the gate driver 612 can be configured to control the power switch within the power switch circuit 604. Specifically, the gate driver 612 is configured to deliver a modulation signal to the control node of the power switch within the power switch circuit 604 to control the on / off switching of the power switch. The voltage and current sensing unit 614 is configured to perform current measurements and voltage measurements associated with temperature-related circuit elements within the power switch circuit 604. As described herein, these voltage measurements and current measurements can be paired and timed according to the switching period associated with the on / off switching of the power switch within the power switch circuit 604. In addition, the timing of the voltage measurement and current measurement of the high side performed via the voltage and current sensing unit 614 can be coordinated with respect to the timing of the voltage measurement and current measurement of the low side performed via the voltage and current sensing unit 648.

[0062] On the low side, the gate driver 642 can be configured to control the power switch within the power switch circuit 654. Specifically, the gate driver 642 is configured to deliver a modulation signal to the control node of the power switch within the power switch circuit 654 to control the on / off switching of the power switch. The voltage and current sensing unit 648 is configured to perform current measurements and voltage measurements associated with temperature-related circuit elements within the power switch circuit 654. As described herein, these voltage measurements and current measurements can be paired and timed according to the switching period associated with the on / off switching of the power switch within the power switch circuit 654. In addition, the timing of the voltage measurement and current measurement of the low side performed via the voltage and current sensing unit 648 can be coordinated with respect to the timing of the voltage measurement and current measurement of the high side performed via the voltage and current sensing unit 614.

[0063] Again, according to the present disclosure, the current measurement and voltage measurement performed by the voltage and current sensing unit 614 on the high side may include paired measurements. Similarly, the current measurement and voltage measurement performed by the voltage and current sensing unit 648 on the low side may include paired measurements. In addition, in some cases, paired measurements may be performed periodically by the voltage and current sensing units 614 and 648, such as every other switching period or periodically. In some cases, the voltage and current sensing units 614 and 648 may perform sensing in a complementary manner, for example, the voltage and current sensing unit 614 operates in one switching period, while the voltage and current sensing unit 648 operates in another (different) switching period, or the voltage and current sensing unit 614 operates in a part or stage of the switching period, while the voltage and current sensing unit 648 operates in another (different) part or stage of the switching period.

[0064] The synchronization unit 624 can deliver a measurement trigger signal to the voltage and current sensing units 614 and 648 to coordinate the timing of the paired measurements of the high side and the low side. For both the high side and the low side, the current measurement and the voltage measurement can be performed based on the timing associated with the on / off switching of the power switch. The synchronization unit 624 can receive a signal (or a mirror image of the signal) associated with the PWM control signal from the control unit 622, which is also delivered to the gate drivers 612 and 642 in a complementary manner. In this way, the synchronization unit 624 can identify the time when the power switch in the power switch circuit 604 or 654 is stable to trigger the paired measurements performed by the voltage and sensing unit 614 and the voltage and sensing unit 648.

[0065] On the high side, the impedance function unit 636 can determine the impedance of the first temperature-dependent circuit element having the power switch circuit 604 based on the paired current measurement and the voltage measurement to essentially apply Ohm's law to calculate the impedance of the temperature-dependent circuit element based on the measured voltage and current on and through the temperature-dependent circuit element. Similarly, on the low side, the impedance function unit 650 can determine the impedance of the second temperature-dependent circuit element having the power switch circuit 654 based on the paired current measurement and the voltage measurement.

[0066] The impedance calculated by the impedance function units 636 and 648 can be used as an indicator of temperature. Therefore, the impedance function units 636 and 648 can provide signals indicating the impedance calculation to the local decision units 630 and 646, respectively. The local decision unit 630 can control the logic within the gate driver 612 of the high side to provide an immediate driver response to the temperature. In some cases, the logic within the gate driver 612 can react to temperature-related changes (e.g., due to high temperature) in the circuit operation of the high side by causing the gate driver 612 to disable the power supply of the power switch in the power switch circuit 604 or adjust the transition time of the power switch in the power switch circuit 604. Similarly, the logic within the gate driver 642 can react to temperature-related changes (e.g., due to high temperature) in the circuit operation of the low side by causing the gate driver 642 to disable the power supply of the power switch in the power switch circuit 654 or adjust the transition time of the power switch in the power switch circuit 654.

[0067] In addition, impedance function units 636 and 648 can provide signals indicating impedance calculations to temperature function units 634 and 652, respectively. Temperature function units 634 and 652 can apply mathematical functions or lookup tables (LUTs) to calculate temperature based on measured impedance. The content of the LUT can be filled with calculated values, or can be filled with values ​​detailed during reference measurements using known temperatures. The temperature indication can be delivered to the system decision standard unit 632 from the temperature function units 634 and 652 (associated with high-side and low-side switches, respectively). The system decision standard unit 632 can then provide a signal for system-level reaction to the control unit 622, so that the control unit can adjust or modify system operation based on the calculated temperature associated with the high-side and low-side switches, respectively. For example, the control unit 622 can adjust the PWM signal for the first gate driver 612, the second gate driver 642, or both gate drivers 612 and 642 based on the calculated temperature. In some examples, temperature function units 634 and 652 may also be eliminated, in which case control unit 622 may be configured to adjust the modulation signal based on the determined impedance determined by impedance function units 636 and 650. However, from a digital point of view, it is generally desirable to program control unit 822 in the temperature domain (rather than the impedance domain), even though the calculated input impedance of the temperature-dependent circuit element may be mathematically related to temperature.

[0068] In some examples, various units within the circuit device 600 may be configurable, for example, to configure one or more configurable parameters that define the circuit operation response to temperature. For example, the configuration unit 644 (which may be an external programming unit) may be able to configure the local reaction thresholds defined by the local decision criteria units 630 and 646. Alternatively or additionally, the configuration unit 644 may be able to configure the temperature functions within the temperature function units 634 and 652, such as by defining or configuring a lookup table based on testing. Furthermore, in some examples, the configuration unit 644 may be able to define one or more system reaction thresholds for the system decision criteria unit 632, such as, for example, by defining a temperature threshold at which the PWM signal should be adjusted. For example, the various configurable parameters may be derived from testing (e.g., during one or more production tests) and may be stored in a memory associated with the unit or controller, such as a one-time programmable (OTP) memory, flash memory, electrically erasable programmable read-only memory (EEPROM), or any type of volatile or non-volatile memory.

[0069] Figure 7 is a block diagram of an example circuit arrangement 700 including a gate driver circuit 702 that includes a high ohmic path 742 and a low ohmic path 744. In this example, the gate driver circuit 702 can be used to modulate its output impedance to facilitate accurate temperature measurement based on a known ratio of voltages associated with the high ohmic path 742.

[0070] The gate driver circuit 702 may be configured to control a power switch circuit 704 that includes a power switch and a temperature-dependent circuit element electrically coupled to at least one node of the power switch. Figure 2 Additional details of power switch circuit 204 , which is similar to power switch circuit 704 , are provided.

[0071] The gate driver circuit 702 may be configured to be coupled to the gate driver power supply circuit 720, and the gate driver circuit 702 may be configured to deliver a modulation signal to a control node of a power switch within the power switch circuit 704 to control the on / off switching of the power switch. In addition, the gate driver circuit 702 may also be configured to modulate its output impedance at the control node of the power switch within the power switch circuit 704. In some examples, an external gate resistor 730 may be positioned between the gate driver circuit 702 and the power switch circuit 704. For example, the external gate resistor 730 may define an impedance of less than 10 ohms.

[0072] The voltage check / measurement unit 734 of the gate driver circuit 702 can be configured to perform one or more voltage measurements while the gate driver circuit 702 modulates the output impedance, and the gate driver circuit 702 can control the power switch within the power switch circuit 704 based at least in part on the one or more voltage measurements. The voltage check timing unit 732 can be configured to coordinate the output impedance modulation and the voltage sensing by controlling the switches 713A and 713B and providing a signal to the voltage check / measurement unit 734. In order to modulate the output impedance of the gate driver circuit 702 at the control node of the power switch within the power switch circuit 704, the gate driver circuit 702 can include a low ohmic path 744 from the gate driver power supply 720 to the control node of the power switch within the power switch circuit 704 and a high ohmic path 742 from the gate driver power supply 720 to the control node. One or more switches 713A and 713B can be configured to switch the gate driver circuit 702 between the low ohmic path and the high ohmic path. For example, the voltage check timing unit 732 can control switches 713A and 713B based on the PWM signal to ensure that the modulation of the output impedance of the gate driver circuit 702 (and the voltage sensing during such modulation) occurs at the appropriate time within the PWM period in which the power switch is stable. In order to modulate its output impedance, the voltage check timing unit 732 of the gate driver circuit 702 can be configured to switch the gate driver circuit 702 from the low ohmic path 744 to the high ohmic path 742, and the voltage check measurement unit 734 can be configured to perform one or more voltage measurements while the gate driver circuit 702 is configured to define the high ohmic path. The one or more voltage measurements can be performed at the output of the gate driver circuit 702 and can be used to calculate the input impedance of the temperature-dependent circuit elements within the power switch circuit 704.

[0073] In some cases, the voltage check measurement unit 734 can perform one or more measurements of a voltage associated with the gate driver circuit 702, and use the voltage measurement and a ratio associated with the high ohmic path 742 to determine the input impedance of the temperature-dependent circuit element within the power switch circuit 704. In this manner, the gate driver circuit 702 can be configured to calculate the input impedance of the temperature-dependent circuit element within the power switch circuit 704 based on the one or more voltage measurements of the voltage check measurement unit 734 and the ratio when modulating the output impedance of the gate driver circuit 702. The low ohmic path 744 can include a normal electrical path used when delivering a control signal to the power switch circuit 704, while the high ohmic path 742 can include an alternative path with a high resistance that is modulated to a control node of the power switch circuit 704 when the power switch is stable to facilitate temperature determination based on the measured voltage and the known ohmic ratio defined by the high ohmic path 742. A network of one or more resistors can be used to define the high ohmic path 742, but other components can also be used to modulate the output impedance of the gate driver circuit 702. For example, other components that may be used for such output impedance modulation may include one or more analog-to-digital converters, one or more switches, or other electrical elements or components.

[0074] The voltage check timing unit 732 can be configured to switch from the low ohmic path 744 to the high ohmic path 742 and cause the voltage check measurement unit 734 to perform one or more voltage measurements based on the timing associated with the on / off switching of the power switch. In some examples, when the power switch within the power switch circuit 704 is stable and the power switch is not in a transition state, the voltage check timing unit 732 is configured to modulate the gate driver circuit 702 from the low ohmic path 744 to the high ohmic path 742 and cause the voltage check measurement unit 734 to perform one or more voltage measurements. In some examples, the gate driver can determine that the driver power supply voltage from the gate driver power supply 720 is stable. In some examples, the voltage check measurement unit 734 can coordinate impedance modulation and voltage sensing based on the PWM signal. In some cases, the one or more voltage measurements performed by the voltage check measurement unit 734 are performed when the power switch within the power switch circuit 704 is turned on, stable, and not in a transition state. Alternatively, the one or more voltage measurements performed by the voltage-check measurement unit 734 can be performed when the power switch is off, in which case the gate driver circuit 702 can be configured to apply a negative voltage to the control node of the power switch circuit 704 during the one or more voltage measurements. In some examples, the voltage-check measurement unit 734 can be configured to inhibit sensing when the power switch within the power switch circuit 704 is unstable or operating in a transition state.

[0075] In some cases, the gate driver circuit 702 can be configured to modulate from a state defining a low ohmic path 744 to a state defining a high ohmic path 742, and perform one or more voltage measurements multiple times within a switching period of the power switch. In other cases, the gate driver circuit 702 can be configured to modulate from a state defining a low ohmic path 744 to a state defining a high ohmic path 742, and perform one or more voltage measurements multiple times within consecutive switching periods of the power switch within the power switch circuit 704 or periodically every Nth period of the power switch, where N is a positive integer. In addition, in other cases, the gate driver circuit 702 can be configured to modulate from a state defining a low ohmic path 744 to a state defining a high ohmic path 742, and in response to a control unit ( Figure 7 The voltage measurement unit 734 may be configured to perform one or more voltage measurements by a command or trigger of (not shown in FIG. 1 ). In some cases, the voltage check measurement unit 734 may include an analog-to-digital converter (ADC) or an analog amplifier or an analog comparator.

[0076] The result reaction unit 736 may generally represent any of a variety of driver control techniques that may be used to control a power switch within the power switch circuit 704 in response to temperature detection. In some examples, the result reaction unit 736 includes logic configured to control a power switch within the power switch circuit 704 in response to one or more voltage measurements and a known ratio indicating a temperature of the power switch. For example, the unit 736 may be configured to respond to one or more temperature-related changes in the operation of the power switch circuit 704. For example, the logic may be configured to adjust a transition speed of a power switch within the power switch circuit 704 in response to one or more voltage measurements (and a known ratio) indicating a temperature of the power switch. As another example, the logic may be configured to disable a power switch within the power switch circuit 704 in response to one or more voltage measurements (and a known ratio) indicating a temperature of the power switch, which may provide device protection. Disabling the power switch may include turning off the power switch, and in some cases, disabling the power switch may also include preventing the power switch from turning on. As described above, in some cases, the circuit response can occur based on a calculation of an impedance indicative of the temperature of a power switch within the power switch circuit 704 (e.g., an input impedance of a temperature-dependent circuit element within the power switch circuit 704). Thus. In some examples, the logic within unit 736 can be configured to control the power switch in response to a calculation of an impedance indicative of the temperature of the power switch, wherein the calculation of the impedance is based on a voltage measurement and a known ratio associated with the high-ohmic path 742. In another example, the result reaction unit 736 can include a communication channel to a control unit (e.g., a digital microprocessor, FPGA, ASIC, CPLD, or microcontroller) to allow a system-level response to temperature. In this case, the control unit ( Figure 7 ) can adjust the PWM signal (e.g., adjust the duty cycle) based on temperature, which can be sent via a signal from unit 736.

[0077] In some examples, the voltage check measurement unit 734 of the gate driver circuit 702 can be configured to perform several voltage measurements within the same switching period of the power switch in the power switch circuit 704. In addition, in some examples, the voltage check measurement unit 734 of the gate driver circuit 702 can be configured to perform voltage measurements multiple times within each switching period of the power switch. In some examples, a filter structure can be used to filter the results of several paired measurements to reduce the noise impact or distortion of a single measurement. In other cases, the voltage check measurement unit 734 of the gate driver circuit 402 can be configured to perform one or more voltage measurements multiple times within a continuous switching period (e.g., each period or every Nth period). In addition, in some cases, the voltage check measurement unit 734 of the gate driver circuit 702 can be configured to perform one or more voltage measurements in response to a command or trigger from a controller (not shown). The voltage check measurement unit 734 can be configured to suppress voltage sensing when the power switch in the power switch circuit 704 is unstable or in a transition state.

[0078] Figure 8 is an example of another block diagram consistent with the techniques of this disclosure and including both a low-side power switch circuit and a low-side gate driver circuit and a high-side power switch and a high-side driver circuit. Figure 8 Examples include a first power switch circuit 804 and a second power switch circuit 854, which can be referred to as a high-side and a low-side power switch circuit. A switch node between the first power switch circuit 804 and the second power switch circuit 854 delivers power to the load based on the on / off switching of the power switches within the circuits 804 and 854.

[0079] The first gate driver 812 (which includes the ability to modulate to a high ohmic path) delivers a modulation control signal to the high-side power switch in the power switch circuit 804, and the second gate driver 842 (which includes the ability to modulate to a high ohmic path) delivers a modulation control signal to the low-side power switch in the power switch circuit 854. The control unit 822 can deliver PWM commands to the gate drivers 804 and 842 to coordinate the on / off switching of the high-side and low-side power switches. External gate resistors 821 and 841 can be included between the control terminals of the power switch circuits 804 and 854 and the gate drivers 812 and 842, respectively. For example, these external gate resistors 821 and 841 can define a resistance less than 10 ohms. The gate driver power supplies 820 and 840 can provide the power required to operate the gate drivers 812 and 842.

[0080] On the high side, the gate driver 812 may be configured to control a power switch within the power switch circuit 804. Specifically, the gate driver 812 is configured to deliver a modulation signal to a control node of the power switch within the power switch circuit 804 to control the on / off switching of the power switch. The voltage (ratio) sensing unit 814 is configured to perform voltage measurements associated with temperature-dependent circuit elements within the power switch circuit 804. As described herein, the voltage measurements may be timed according to the switching period associated with the on / off switching of the power switch within the power switch circuit 804. According to the present disclosure, the voltage measurements of the voltage (ratio) sensing unit 814 may be used together with a known ratio associated with the high-ohmic path of the gate driver 812 to determine the input impedance of the temperature-dependent circuit element within the power switch circuit 804. In addition, the timing of the voltage measurement of the high side (and the corresponding modulation of the high-ohmic path by the gate driver 812) performed by the voltage (ratio) sensing unit 814 may be coordinated with respect to the timing of the voltage measurement of the low side (and the corresponding modulation of the driver output impedance) performed via the voltage (ratio) sensing unit 848.

[0081] On the low side, the gate driver 842 can be configured to control the power switch within the power switch circuit 854. Specifically, the gate driver 842 is configured to deliver a modulation signal to the control node of the power switch within the power switch circuit 854 to control the on / off switching of the power switch. The voltage (ratio) sensing unit 848 is configured to perform voltage measurements associated with temperature-dependent circuit elements within the power switch circuit 854 when the output impedance of the gate driver 842 is modulated to a high-ohmic path. As described herein, the voltage measurement (and the corresponding modulation of the driver output impedance) can be timed according to the switching period associated with the on / off switching of the power switch within the power switch circuit 854. In addition, the timing of the voltage measurement of the low side performed via the voltage (ratio) sensing unit 848 can be coordinated with respect to the timing of the voltage measurement of the high side performed via the voltage (ratio) sensing unit 814.

[0082] In some cases, the high-side and low-side voltage measurements (and the corresponding modulation of the driver output impedance) can be performed by the voltage (ratio) sensing units 814 and 848 periodically, such as every other switching period or periodically. In some cases, the voltage (ratio) sensing units 814 and 848 can perform sensing in a complementary manner, for example, the voltage (ratio) sensing unit 814 operates in one switching period, while the voltage (ratio) sensing unit 848 operates in another (different) switching period. As another example, the voltage (ratio) sensing units 814 and 848 can perform sensing in a complementary manner, for example, the voltage (ratio) sensing unit 814 operates in a part or phase of the switching period, while the voltage (ratio) sensing unit 848 operates in another (different) part or phase of the switching period.

[0083] The synchronization unit 824 can deliver a measurement trigger signal to the voltage (ratio) sensing units 814 and 848 to coordinate the timing of the voltage measurement of the high side and the low side, for example, when the driver output impedance is also modulated to the high ohmic path. For the high side and the low side, the voltage measurement (and the corresponding modulation of the driver output impedance) can be performed based on the timing associated with the on / off switching of the power switch. The synchronization unit 824 can receive a signal (or a mirror image of the signal) associated with the PWM control signal from the control unit 822, which is also delivered to the gate drivers 812 and 842 in a complementary manner. In this way, the synchronization unit 824 can identify the time when the power switch within the power switch circuit 804 or 854 is stable and the driver output impedance can be modulated to trigger the measurement performed by the voltage (ratio) sensing unit 814 and the voltage (ratio) sensing unit 848.

[0084] On the high side, the impedance function unit 836 can determine the impedance of the first temperature-dependent circuit element having the power switch circuit 604 based on one or more voltage measurements associated with the high-ohmic path of the gate driver 812. Similarly, on the low side, the impedance function unit 850 can determine the impedance of the second temperature-dependent circuit element having the power switch circuit 854 based on one or more voltage measurements associated with the high-ohmic path of the gate driver 842.

[0085] The impedance calculated by the impedance function units 836 and 848 can be used as an indicator of temperature. Therefore, the impedance function units 836 and 848 can provide signals indicating the impedance calculation to the local decision units 830 and 846, respectively. The local decision unit 830 can control the logic within the gate driver 812 of the high side to provide an immediate driver reaction to the temperature. In some cases, the logic within the gate driver 812 can react to temperature-related changes in the circuit operation of the high side by causing the gate driver 812 to disable the power supply of the power switch in the power switch circuit 804 or adjust the transition time of the power switch in the power switch circuit 804. Similarly, the logic within the gate driver 842 can react to temperature-related changes in the circuit operation of the low side by causing the gate driver 842 to disable the power supply of the power switch in the power switch circuit 854 or adjust the transition time of the power switch in the power switch circuit 854.

[0086] In addition, the impedance function unit 836 and 848 can provide a signal indicating impedance calculation to the temperature function unit 834 and 852, respectively. The temperature function unit 834 and 852 can apply a mathematical function or a lookup table (LUT) to calculate the temperature based on the measured impedance. For example, the content of the LUT can be filled with a calculated value, or can be filled with a value detailed during a reference measurement using a known temperature. The temperature indication can be delivered to the system decision standard unit 832 from the temperature function unit 834 and 852 (associated with the high side and low side switches, respectively). The system decision standard unit 832 can then provide a signal for system-level reaction to the control unit 822, so that the control unit can adjust or modify the system operation based on the calculated temperature associated with the high side and low side switches, respectively. For example, the control unit 822 can adjust the PWM signal for the first gate driver 812, the second gate driver 842, or both gate drivers 812 and 842 based on the calculated temperature. In some examples, temperature function units 834 and 852 may also be eliminated, in which case control unit 822 may be configured to adjust the modulation signal based on the determined impedance determined by impedance function units 836 and 850. However, from a digital point of view, it is generally desirable to program control unit 822 in the temperature domain (rather than the impedance domain), even though the calculated input impedance of the temperature-dependent circuit element may be mathematically related to temperature. Likewise, if a LUT is used, the data within the LUT may be determined using calculated values, or may be defined using values ​​detailed during a reference measurement using a known temperature.

[0087] and Figure 6 The same as the circuit arrangement 600, Figure 8Various units within the circuit arrangement 800 of can be configurable, for example, to configure one or more configurable parameters that define the circuit operation response to temperature. For example, a configuration unit 844 (which can be an external programming unit) can be capable of configuring the local reaction thresholds defined by the local decision criteria units 830 and 846. Alternatively or additionally, the configuration unit 844 can be capable of configuring the temperature functions within the temperature function units 834 and 852, such as by defining or configuring a lookup table based on testing. Furthermore, in some examples, the configuration unit 844 can be capable of defining one or more system reaction thresholds for the system decision criteria unit 832, such as, for example, by defining a temperature threshold at which the PWM signal should be adjusted. For example, various configurable parameters can be derived from testing (e.g., during one or more production tests) and may be stored in a memory associated with the unit or controller, such as a one-time programmable (OTP) memory, flash memory, electrically erasable programmable read-only memory (EEPROM), or any type of volatile or non-volatile memory.

[0088] According to the present disclosure, in some cases, the driver circuit may be configured to determine the power switch temperature based on paired current measurements and voltage measurements at specific times within a switching period of the power switch. In other cases, according to the present disclosure, the driver circuit may be configured to determine the power switch temperature by modulating from a low ohmic path to a high ohmic path to modulate the output impedance of the driver circuit and then performing one or more voltage measurements at specific times within the switching period of the power switch. In any of these scenarios, the specific sensing time may occur multiple times within a switching period of the power switch. In other cases, the specific sensing time may occur multiple times within a continuous switching period of one or more power switches, such as every Nth period of the power switch 804, where N is a positive integer. In addition, in other cases, the driver circuit may be configured to perform sensing in response to a command or trigger from a control unit. In some examples, a filter structure may be used to filter the results of several paired measurements to reduce the noise impact or distortion of a single measurement.

[0089] Fig. 9 is to show the high-side and low-side switches (e.g., Figure 6 The power switch circuits 604 and 654 or Figure 8 A timing diagram for a specific timing of temperature sensing of the power switching circuits 804 and 854). Fig. 9 This is just one example, and many other timing sequences for temperature sensing may be used based on the on / off switching of the power switch as described herein. Fig. 9In a specific example, Figure 901 shows the switching period of the high-side power switch, and Figure 902 shows the complementary switching period of the low-side power switch. For the high-side switch, the temperature sensing diagram 903 shows the sensing events 905A, 905B and 905C. For the low-side switch, the temperature sensing diagram 904 shows the sensing events 906A, 906B and 906C. In this example, the temperature sensing events 905A, 905B and 905C associated with the high-side switch are performed when the high-side switch is stable and turned on and when the low-side switch is stable and not conducting. In addition, in this example, the temperature sensing events 906A, 906B and 906C associated with the low-side switch are performed when the low-side switch is stable and turned on and when the high-side switch is stable and not conducting. In some examples, events 905A, 905B and 905C can correspond to current sensing events and multiple voltage sensing events, and events 906A, 906B and 906C can correspond to current sensing events and multiple voltage sensing events. In other examples, events 905A, 905B, and 905C may correspond to voltage sensing events corresponding to modulation of the driver output impedance of the high side, and events 906A, 906B, and 906C may correspond to voltage sensing events corresponding to modulation of the driver output impedance of the low side. Many other timing schemes may be used to provide sensing events at each switching period, periodically provide sensing events at every Nth switching period, provide sensing events in response to a trigger or command, provide sensing events across multiple switching periods, or provide timing schemes based on on / off switching of one or more power switches. Again, in some examples, a filter structure may be used to filter the results of several paired measurements to reduce noise effects or distortion of a single measurement.

[0090] Fig.10 and 11 are two exemplary flow charts of temperature sensing and control techniques using paired voltage and current measurements consistent with the present disclosure. Figure 3 The driver circuit 304 of the circuit arrangement 300 is described from the perspective of Fig.10 , although other circuits or circuit arrangements may be used to implement Fig.10 technology. Fig.10 is an example of a method for controlling a power switch circuit 304 including a power switch 308 and a temperature-dependent circuit element 306 electrically coupled to at least one node of the power switch. Fig.10As shown, the driver 312 of the driver circuit 302 delivers a modulated signal to the control node of the power switch 308 to control the on / off switching of the power switch 308 (1001). The current sensing unit 314 performs a current measurement associated with the temperature-dependent circuit element 306 (1002), and the voltage sensing unit 314 performs a voltage measurement associated with the temperature-dependent circuit element 306 (1003). The current measurement and the voltage measurement can be paired and can be based on the timing of the on / off switching of the power switch 308, for example, when the power switch 308 is stable and not in a transition state. The driver circuit 312 can then control the power switch 308 based at least in part on the current measurement and the voltage measurement (1004). In some examples, controlling the power switch can include controlling the power switch circuit in response to a current measurement and a voltage measurement indicating the temperature of the power switch. In some examples, Fig.10 The method may also include the steps of calculating an impedance (eg, an input impedance of the temperature-dependent circuit element 306) based on the current measurement and the voltage measurement, and controlling the power switch based on the calculated impedance. In some examples, Fig.10 The method may further include the step of determining a temperature of the power switch based on the current measurement and the voltage measurement, wherein controlling the power switch includes adjusting the modulation signal via the controller based on the determined temperature. Many other details described above may also be applied to Fig.10 The method shown.

[0091] Fig.11 is another flow chart of a temperature sensing and control technique using paired voltage and current measurements consistent with the present disclosure. Figure 6 Description of the circuit arrangement 600 in the perspective Fig.11 , although other circuits or circuit arrangements may be used to implement Figure 1 technology.

[0092] according to Fig.11 , the external configuration and calibration unit 644 may be used to configure parameters (1001) of one or more units within the circuit arrangement 600, such logic being associated with the local decision criteria 630, LUTs, or mathematical equations applied by the temperature function unit 634 and / or the system decision criteria applied by the unit 632. For example, the ability to configure the circuit arrangement 600 during the manufacturing and testing phase may be highly desirable so that the circuit arrangement 600 can be tuned for different uses and applications (e.g., for controlling different types of loads or load arrangements in a variety of different settings).

[0093] In operation, the gate driver 612 delivers a modulated control signal (1102) to the control terminal of the power switch circuit 604, for example, through an external gate resistor 621, which can control the on / off switching of the power switch within the power switch circuit 604. The voltage and current sensing unit 614 performs one or more voltage measurements (1104) based on the timing of the modulated signal, and performs one or more current measurements (1105) based on the timing of the modulated signal, which can define paired measurements for temperature determination and control. Fig.11 In an example of , logic within the local decision criteria unit 630 can be configured to disable operation of a power switch within the power switch circuit 604 if a measurement indicates a temperature-related change in circuit operation (1105). For example, a temperature-related change in circuit operation can be indicated by a high temperature, which can be defined or determined locally (e.g., by a driver circuit system) via an impedance indication calculated by the impedance function unit 636. For example, the calculated impedance can include a measurement of an input impedance of a temperature-dependent circuit element within the power switch circuit 604, which can be mapped to a temperature estimate of the power switch circuit 604. This local response to temperature (via a response to the impedance calculation) can be faster than a system response to provide circuit and system protection against temperature changes in circuit operation. In addition to this immediate local response, Fig.11 The method can also facilitate a system response to temperature, which may be a more gradual and preventative measure over time to help avoid overheating before it occurs. For example, the temperature function unit 636 can determine a temperature indication (1106) based on the current measurement and the voltage measurement, such as by applying a LUT to map the calculated impedance to the temperature indication. Since the calculated impedance is based on paired current measurements and voltage measurements, the temperature indication is ultimately based on paired measurements. In other examples, the calculated impedance can also be used to cause a system-level reaction, but system-level configuration using temperature may be required, and thus the calculated impedance may need to be mapped to the temperature indication via the temperature function unit 634. The control unit 622 can then adjust the modulation signal (1107) based on the determined temperature, such as by increasing or decreasing the duty cycle, which in turn can allow predictive or preventative protection against rising temperature trends. These steps and many of the other details described above can also be applied to Fig.11 The method shown.

[0094] Fig.12 and 13 is a flow chart of a temperature sensing and control technique using modulation of the driver output impedance and one or more voltage measurements consistent with the present disclosure. Figure 4 The driver circuit 404 of the circuit arrangement 400 is described from the perspective of Fig.12, although other circuits or circuit arrangements may be used to implement Fig.12 technology. Fig.12 4 is an example of a method for controlling a power switch circuit 404 including a power switch 408 and a temperature-dependent circuit element 406 electrically coupled to at least one node of the power switch. Fig.12 As shown, the driver 412 of the driver circuit 402 delivers a modulation signal to the control node of the power switch 408 to control the on / off switching of the power switch 408 (1001). The driver 412 modulates its output impedance (1202) at the control node, such as by switching from the low-ohmic path 417 to the high-ohmic path 418. The low-ohmic path 417 and the high-ohmic path 418 may include alternative electrical paths through the driver circuit 412 to the control node of the power switch 408 within the power switch circuit 404. Alternatively, the low-ohmic path 417 and the high-ohmic path 418 may be defined by a common path with different operating conditions. In any case, while the driver 412 defines the high-ohmic path 418, the voltage sensing unit 416 performs one or more voltage measurements (1203). As described herein, for example, when the power switch 408 is stable and the power switch 408 is not in a transition state, switching the path of the driver circuit 412 from the low-ohmic path 417 to the high-ohmic path 418 and performing one or more voltage measurements can be performed according to a timing sequence based on the timing associated with the on / off switching of the power switch 408.

[0095] The driver circuit 412 can control the power switch 408 based at least in part on one or more voltage measurements (1204). For example, the driver 412 can use the one or more voltage measurements in combination with a known ratio associated with the high-ohmic path 418 to determine the input impedance of the temperature-dependent circuit element 406, and the input impedance or voltage ratio can indicate the temperature of the power switch circuit 404.

[0096] In some examples, controlling the power switch can include controlling the power switch circuit in response to one or more voltage measurements (and ratios) indicative of a temperature of the power switch. Fig.12 The method may also include the steps of calculating an impedance (eg, an input impedance of the temperature-dependent circuit element 406) based on the voltage measurements (and ratios) and controlling the power switch based on the calculated impedance or voltage ratio. In some examples, Fig.12 The method may further include the step of determining a temperature of the power switch based on one or more voltage measurements, wherein controlling the power switch includes adjusting the modulation signal via the controller based on the determined temperature. Many other details described above may also be applied to Fig.12 The method shown.

[0097] Fig.13 is another flow chart of a temperature sensing and control technique using modulation of the driver output impedance and one or more voltage measurements consistent with the present disclosure. Figure 8 Description of the circuit arrangement 800 in perspective Fig.13 , although other circuits or circuit arrangements may be used to implement Fig.13 technology.

[0098] according to Fig.13 , the external configuration and calibration unit 844 may be used to configure parameters (1301) of one or more units within the circuit arrangement 800, such logic being associated with the local decision criteria 830, LUTs, or mathematical equations applied by the temperature function unit 834 and / or the system decision criteria applied by the unit 832. For example, the ability to configure the circuit arrangement 800 during the manufacturing and testing phase may be highly desirable so that the circuit arrangement 800 can be tuned for different uses and applications (e.g., for controlling different types of loads or load arrangements in a variety of different settings).

[0099] In operation, the gate driver 812 delivers a modulated control signal (1302) to the control terminal of the power switch circuit 804, for example, through the external gate resistor 821, which can control the on / off switching of the power switch within the power switch circuit 804. The gate driver 812 modulates to a high ohmic path so as to modulate the output impedance (1303) of the gate driver 812 at the control node of the power switch associated with the power switch circuit 804. While the gate driver 812 modulates its output impedance to the high ohmic path to define the high driver output impedance, the voltage (ratio) sensing unit 814 performs one or more voltage measurements (1304) based on the timing of the modulated signal. The timing of modulating the output impedance (1303) of the gate driver 812 and performing the one or more voltage measurements (1304) can be based on the timing of the modulated control signal that defines the on / off switching of the power switch within the power switch circuit 804, for example, when the power switch is stable and not in a transition state.

[0100] Similar to Fig.11 For example, Fig.13In an example of , logic within the local decision criteria unit 830 can be configured to disable operation of a power switch within the power switch circuit 804 if a measurement indicates a temperature-related change in circuit operation (1305). For example, a temperature-related change in circuit operation can be indicated by a high temperature, which can be defined or determined locally (e.g., by a driver circuit system) via an impedance indication calculated by the impedance function unit 836. For example, the calculated impedance can include a measurement of an input impedance of a temperature-dependent circuit element within the power switch circuit 804, which can be mapped to a temperature estimate of the power switch circuit 804. This local response to temperature (via a response to the impedance calculation) can be faster than a system response to provide circuit and system protection against temperature-related changes in circuit operation. In addition to this immediate local response, Fig.13 The method can also facilitate a system response to temperature, which may be a more gradual and preventative measure over time to help avoid overheating before it occurs. For example, the temperature function unit 836 can determine a temperature indication (1306) based on the current measurement and the voltage measurement, such as by applying a LUT to map the calculated impedance or voltage ratio to the temperature indication. Since the calculated impedance or voltage ratio is based on paired measurements, the temperature indication is ultimately based on paired measurements. In other examples, the calculated impedance or voltage ratio can also be used to cause a system-level reaction, but system-level configuration using temperature may be required, and thus the calculated impedance or voltage ratio may need to be mapped to a temperature indication via the temperature function unit 834. The control unit 822 can then adjust the modulation signal (1107) based on the determined temperature, for example, by increasing or decreasing the duty cycle, which in turn can allow predictive or preventative protection against rising temperature trends. These steps and many of the other details described above can also be applied to Fig.13 The method shown.

[0101] The following examples may illustrate one or more aspects of the present disclosure.

[0102] Example 1 - A circuit comprising a driver circuit, the driver circuit being configured to control a power switch circuit, the power switch circuit comprising a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch: wherein the driver circuit is configured to deliver a modulated signal to a control node of the power switch to control on / off switching of the power switch, wherein the driver circuit is configured to perform current measurements and voltage measurements associated with the temperature-dependent circuit element and control the power switch at least partially based on the current measurements and the voltage measurements, and wherein the current measurements and the voltage measurements are performed based on timing associated with the on / off switching of the power switch.

[0103] Example 2 - The circuit of Example 1, wherein the current measurement and the voltage measurement are performed when the voltage across the power switch is stable and the power switch is not in a transition state.

[0104] Example 3 - The circuit of Example 1 or 2, wherein the current measurement and the voltage measurement are performed when the power switch is turned on.

[0105] Example 4 - A circuit according to Example 1 or 2, wherein the current measurement and the voltage measurement are performed when the power switch is turned off, and wherein the driver circuit is configured to apply a negative voltage to the control node during the current measurement and the voltage measurement.

[0106] Example 5 - A circuit according to any of Examples 1-4, wherein the current measurement and the voltage measurement are measured in pairs.

[0107] Example 6 - The circuit of Example 5, wherein the circuit is configured to store pairs of measurements.

[0108] Example 7 - The circuit of any of Examples 1-6, wherein the voltage measurement comprises a measurement of a voltage supplied to the driver circuit to drive the power switch.

[0109] Example 8 - The circuit of any of Examples 1-6, wherein the voltage measurement comprises a measurement of a voltage drop across the temperature-dependent circuit element.

[0110] Example 9 - The circuit of any of Examples 1-8, wherein the driver circuit includes logic configured to control the power switch in response to the current measurement and the voltage measurement indicative of a temperature of the power switch.

[0111] Example 10 - The circuit of Example 9, wherein the logic is configured to adjust a transition speed of the power switch in response to the current measurement and the voltage measurement indicative of the temperature of the power switch.

[0112] Example 11 - The circuit of Example 9 or 10, wherein the logic is configured to disable the power switch in response to the current measurement and the voltage measurement being indicative of the temperature of the power switch.

[0113] Example 12 - A circuit according to any of Examples 9-11, wherein the logic is configured to control the power switch in response to a calculation of an impedance indicative of the temperature of the power switch, wherein the calculation of the impedance is based on the current measurement and the voltage measurement.

[0114] Example 13 - The circuit of Example 12, further comprising a control unit configured to adjust the modulation signal based on the determined impedance.

[0115] Example 14 - The circuit of any of Examples 1-13, wherein the driver circuit includes a temperature unit configured to determine a temperature of the power switch based on the current measurement and the voltage measurement.

[0116] Example 15 - The circuit of Example 14, wherein the temperature unit comprises a lookup table, wherein inputs to the lookup table are the current measurement and the voltage measurement.

[0117] Example 16 - A circuit according to any of Examples 1-14, wherein the circuit further includes a control unit configured to adjust the modulation signal based on the determined temperature.

[0118] Example 17 - A circuit according to any of Examples 1-16, wherein the driver circuit includes logic configured to control the power switch in response to the current measurement and the voltage measurement indicative of the temperature of the power switch.

[0119] Example 18 - The circuit of Example 17, wherein the logic is configurable via an external configuration unit that adjusts one or more configurable parameters.

[0120] Example 19 - The circuit of any of Examples 14-18, wherein the temperature unit is configurable via an external configuration unit that adjusts one or more configurable parameters.

[0121] Example 20 - The circuit of any of Examples 13-19, wherein the control unit is configurable via an external configuration unit that adjusts one or more configurable parameters.

[0122] Example 21 - The circuit of any of Examples 1-20, wherein the driver circuit is configured to perform the current measurement and the voltage measurement during a same switching period of the power switch.

[0123] Example 22 - A circuit according to any of Examples 1-21, wherein the driver circuit is configured to perform at least one of the current measurement or the voltage measurement multiple times within each switching period of the power switch.

[0124] Example 23 - A circuit according to any of Examples 1-22, wherein the driver circuit is configured to perform at least one current measurement and multiple voltage measurements within a same switching period of the power switch.

[0125] Example 24 - A circuit according to any one of Examples 1-23, wherein the power switch circuit includes a high-side power switch circuit, the power switch includes a high-side power switch, the temperature-related circuit element includes a first temperature-related circuit element, the modulation signal includes a high-side modulation signal, and the driver circuit includes a high-side driver circuit, the circuit also includes a low-side driver circuit, the low-side driver circuit is configured to deliver a low-side modulation signal to a control node of the low-side power switch to control the on / off switching of the low-side power switch, wherein the low-side driver circuit is also configured to perform current measurement and voltage measurement associated with a second temperature-related circuit element, and control the low-side power switch based at least in part on the current measurement and the voltage measurement associated with the second temperature-related circuit element.

[0126] Example 25 - A circuit according to Example 24, wherein the current measurement and the voltage measurement performed by the high-side driver circuit are performed when both the high-side switch and the low-side switch are stable, one of the high-side switch and the low-side switch is turned on, and one of the high-side switch and the low-side switch is turned off.

[0127] Example 26 - A circuit according to Example 24 or 25, wherein the current measurement and the voltage measurement performed by the low-side driver circuit are performed when both the high-side switch and the low-side switch are stable, one of the high-side switch and the low-side switch is turned on, and one of the high-side switch and the low-side switch is turned off.

[0128] Example 27 - A method for controlling a power switch circuit, the power switch circuit comprising a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch, the method comprising: delivering a modulated signal to a control node of the power switch to control on / off switching of the power switch; performing current measurements associated with the temperature-dependent circuit element; performing voltage measurements associated with the temperature-dependent circuit element; and controlling the power switch based at least in part on the current measurements and the voltage measurements.

[0129] Example 28 - The method of Example 27, further comprising performing the current measurement and the voltage measurement according to a timing sequence based on a timing associated with the on / off switching of the power switch.

[0130] Example 29 - The method of Example 27 or 28, wherein controlling the power switch comprises controlling the power switch circuit in response to the current measurement and the voltage measurement indicative of a temperature of the power switch.

[0131] Example 30 - The method of any of Examples 27-29, further comprising calculating an impedance based on the current measurement and the voltage measurement, and controlling the power switch based on the calculated impedance.

[0132] Example 31 - The method of any of Examples 27-30 further includes determining a temperature of the power switch based on the current measurement and the voltage measurement, wherein controlling the power switch includes adjusting the modulation signal via a controller based on the determined temperature.

[0133] Example 32 - A method according to any of Examples 27-31, wherein performing the current measurement and the voltage measurement includes: performing the current measurement and the voltage measurement in a paired manner.

[0134] Example 33 - The method of Example 32, wherein performing the current measurement and the voltage measurement in a pair comprises performing the current measurement and the voltage measurement within a same switching period of the power switch.

[0135] Example 34 - The method of any of Examples 27-33 further includes: configuring one or more parameters associated with controlling the power switch circuit, wherein the one or more parameters define one or more temperature-related functions associated with controlling the power switch.

[0136] Example 35 - A circuit device comprising: a power switching circuit, including a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch; and a driver circuit, configured to deliver a modulated signal to a control node of the power switch to control on / off switching of the power switch, wherein the driver circuit is configured to perform current measurements and voltage measurements associated with the temperature-dependent circuit element and control the power switch at least partially based on the current measurements and the voltage measurements, and wherein the current measurements and the voltage measurements are performed based on timing associated with the on / off switching of the power switch.

[0137] Example 36 - The circuit arrangement of Example 35, wherein the temperature-dependent circuit element comprises a temperature-dependent resistor.

[0138] Example 37 - A circuit arrangement according to Example 35 or 36, wherein the temperature-dependent circuit element is electrically coupled to the control node of the power switch and a load node of the power switch.

[0139] Example 38 - A circuit device according to any of Examples 35-37, wherein the temperature-dependent circuit element is electrically coupled to a dedicated sense node associated with the power switch circuit and a load node of the power switch.

[0140] Example 39 - A circuit device according to any of Examples 35-38, wherein the driver circuit includes an analog-to-digital converter configured to perform the current measurement.

[0141] Example 40 - A circuit device according to any of Examples 35-39, wherein the driver circuit includes a shunt resistor configured to perform the current measurement.

[0142] Example 41 - A circuit configured to control a power switch circuit, the power switch circuit comprising a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch, the circuit comprising: a driver circuit configured to be coupled to a power supply circuit, wherein the driver circuit is configured to deliver a modulation signal to a control node of the power switch to control on / off switching of the power switch, wherein the driver circuit is also configured to modulate the output impedance of the driver circuit at the control node, perform one or more voltage measurements while modulating the output impedance of the driver circuit, and control the power switch at least in part based on the one or more voltage measurements.

[0143] Example 42 - A circuit according to Example 41, wherein the driver circuit is configured to calculate the input impedance of the temperature-dependent circuit element based on the one or more voltage measurements while modulating the output impedance of the driver circuit.

[0144] Example 43 - A circuit according to Example 41 or 42, wherein the driver circuit includes: a low-ohmic path from the power circuit to the control node; and a high-ohmic path from the power circuit to the control node; wherein one or more control signals are configured to switch the driver circuit between the low-ohmic path and the high-ohmic path, wherein in order to modulate the output impedance, the driver circuit is configured to switch from the low-ohmic path to the high-ohmic path, and wherein while the driver circuit is configured to define the high-ohmic path, the driver circuit is configured to perform the one or more voltage measurements, wherein the one or more voltage measurements are associated with the input impedance of the temperature-dependent circuit element.

[0145] Example 44 - A circuit according to Example 43, wherein the driver circuit is configured to switch from the low-ohmic path to the high-ohmic path and perform the one or more voltage measurements based on a timing associated with the on / off switching of the power switch.

[0146] Example 45 - A circuit according to Example 43 or 44, wherein the driver circuit is configured to switch from the low-ohmic path to the high-ohmic path and perform the one or more voltage measurements when the power switch is stable and the power switch is not in a transition state.

[0147] Example 46 - A circuit according to any of Examples 41-45, wherein the one or more voltage measurements are performed when the power switch is turned on.

[0148] Example 47 - A circuit according to any of Examples 41-45, wherein the one or more voltage measurements are performed when the power switch is turned off, and wherein the driver circuit is configured to apply a negative voltage to the control node during the one or more voltage measurements.

[0149] Example 48 - A circuit according to any of Examples 43-47, wherein the driver circuit is configured to switch from the low-ohmic path to the high-ohmic path and perform the one or more voltage measurements multiple times within a switching period of the power switch.

[0150] Example 49 - A circuit according to any of Examples 41-48, wherein the driver circuit includes a temperature unit configured to determine a temperature of the power switch based on the one or more voltage measurements.

[0151] Example 50 - The circuit of Example 49, wherein the temperature unit comprises a lookup table, wherein an input to the lookup table is based on the one or more voltage measurements.

[0152] Example 51 - A circuit according to any of Examples 41-50, wherein the circuit further includes a control unit configured to adjust the modulation signal based on the determined temperature.

[0153] Example 52 - A circuit according to any of Examples 41-51, wherein the driver circuit includes logic configured to control the power switch in response to the voltage measurement indicating the temperature of the power switch.

[0154] Example 53 - The circuit of Example 52, wherein the logic is configured to adjust a transition speed of the power switch in response to the one or more voltage measurements.

[0155] Example 54 - The circuit of Example 52 or 53, wherein the logic is configured to disable the power switch in response to the one or more voltage measurements.

[0156] Example 55 - A circuit according to any of Examples 52-54, wherein the logic is configured to control the power switch in response to a calculation of an input impedance of the temperature-dependent circuit element, wherein the calculation of the input impedance is based on the one or more voltage measurements while modulating the output impedance of the driver circuit.

[0157] Example 56 - A circuit according to any of Examples 52-55, wherein the logic is configurable via an external configuration unit that adjusts one or more configurable parameters.

[0158] Example 57 - The circuit of Example 49, wherein the temperature unit is configurable via an external configuration unit that adjusts one or more configurable parameters.

[0159] Example 58 - The circuit of Example 51, wherein the control unit is configurable via an external configuration unit that adjusts one or more configurable parameters.

[0160] Example 59 - A circuit according to any one of Examples 41-58, wherein the power switch circuit includes a high-side power switch circuit, the power switch includes a high-side power switch, the power supply circuit includes a high-side power supply circuit, the temperature-related circuit element includes a first temperature-related circuit element, and the driver circuit includes a high-side driver circuit, and the circuit also includes a low-side driver circuit, the low-side driver circuit is configured to be coupled to the low-side power supply circuit, wherein the low-side driver circuit is configured to deliver a modulation signal to a control node of the low-side power switch to control on / off switching of the low-side power switch, wherein the low-side driver circuit is also configured to modulate the output impedance of the low-side driver circuit at the control node, perform one or more voltage measurements while modulating the output impedance of the low-side driver circuit, and control the low-side power switch based at least in part on the one or more voltage measurements.

[0161] Example 60 - A method for controlling a power switch circuit, the power switch circuit comprising a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch, the method comprising: delivering a modulation signal to a control node of the power switch to control on / off switching of the power switch; modulating the output impedance of the driver circuit at the control node; performing one or more voltage measurements while modulating the output impedance of the driver circuit; and controlling the power switch based at least in part on the one or more voltage measurements.

[0162] Example 61 - The method of Example 60 further comprising calculating an input impedance of the temperature-dependent circuit element based on the one or more voltage measurements when modulating the output impedance of the driver circuit.

[0163] Example 62 - A method according to Example 60 or 61, wherein modulating the output impedance includes: switching the path of the driver circuit that delivers the modulation signal from a low-ohmic path to a high-ohmic path, wherein the low-ohmic path and the high-ohmic path are alternating electrical paths through the driver circuit to the control node.

[0164] Example 63 - The method of any of Examples 60-62 further includes switching the path of the driver circuit and performing the one or more voltage measurements according to a timing sequence based on a timing associated with the on / off switching of the power switch.

[0165] Example 64 - The method of any of Examples 60-63 further includes switching the path of the driver circuit and performing the one or more voltage measurements when the power switch is stable and the power switch is not in a transition state.

[0166] Example 65 - The method of any of Examples 60-64, further comprising: switching the path of the driver circuit and performing the one or more voltage measurements multiple times during a switching period of the power switch.

[0167] Example 66 - A method according to any one of Examples 60-65, wherein modulating the output impedance includes: switching the path of the driver circuit that delivers the modulation signal from a low-ohm path to a high-ohm path, wherein the low-ohm path and the high-ohm path are defined by a common path having different operating conditions.

[0168] Example 67 - The method of any of Examples 60-66 further comprising controlling the power switch based at least in part on the one or more voltage measurements.

[0169] Example 68 - The method of any of Examples 60-67, wherein controlling the power switch based in part on the one or more voltage measurements includes disabling the power switch via logic of a driver circuit in response to the one or more voltage measurements.

[0170] Example 69 - A method according to any of Examples 60-68, wherein controlling the power switch based in part on the one or more voltage measurements includes: adjusting a transition speed of the power switch in response to the voltage measurement indicating a temperature of the power switch.

[0171] Example 70 - The method of any of Examples 60-69 further comprising determining a temperature of the power switch based on the one or more voltage measurements.

[0172] Example 71 - The method of any of Examples 60-70, wherein controlling the power switch based in part on the one or more voltage measurements includes adjusting the modulation signal via a controller based on the determined temperature.

[0173] Example 72 - The method of any of Examples 60-71 further includes: configuring one or more parameters associated with controlling the power switch circuit, wherein the one or more parameters define one or more temperature-related functions associated with controlling the power switch.

[0174] Example 73 - A circuit device comprising: a power switch circuit, including a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch; and a driver circuit, configured to be coupled to a power supply circuit, wherein the driver circuit is configured to deliver a modulation signal to a control node of the power switch to control on / off switching of the power switch, wherein the driver circuit is also configured to modulate the output impedance of the driver circuit at the control node, perform one or more voltage measurements while modulating the output impedance of the driver circuit, and control the power switch at least in part based on the one or more voltage measurements.

[0175] Example 74 - A circuit device according to Example 73, wherein the driver circuit is configured to calculate the input impedance of the temperature-dependent circuit element based on the one or more voltage measurements while modulating the output impedance of the driver circuit.

[0176] Example 75 - A circuit device according to Example 73 or 74, wherein the driver circuit includes: a low-ohmic path from the power supply circuit to the control node; and a high-ohmic path from the power supply circuit to the control node; wherein one or more control signals are configured to switch the driver circuit between the low-ohmic path and the high-ohmic path, wherein in order to modulate the output impedance, the driver circuit is configured to switch from the low-ohmic path to the high-ohmic path, and wherein while the driver circuit is configured to define the high-ohmic path, the driver circuit is configured to perform the one or more voltage measurements, wherein the one or more voltage measurements are associated with the input impedance of the temperature-dependent circuit element.

[0177] Example 76 - A circuit device according to Example 75, wherein the driver circuit is configured to switch from the low-ohmic path to the high-ohmic path and perform the one or more voltage measurements based on a timing associated with the on / off switching of the power switch.

[0178] Example 77 - A circuit device according to Example 75 or 76, wherein the driver circuit is configured to switch from the low-ohmic path to the high-ohmic path and perform the one or more voltage measurements when the power switch is stable and the power switch is not in a transition state.

[0179] Example 78 - A circuit device according to any of Examples 73-77, wherein the temperature-dependent circuit element includes a temperature-dependent resistor.

[0180] Example 79 - A circuit device according to any of Examples 73-78, wherein the temperature-dependent circuit element is electrically coupled to the control node of the power switch and a load node of the power switch.

[0181] Example 80 - A circuit device according to any of Examples 73-78, wherein the temperature-dependent circuit element is electrically coupled to a dedicated sense node associated with the power switch circuit and a load node of the power switch.

[0182] Example 81 - A circuit device according to any of Examples 73-80, wherein the driver circuit includes an analog-to-digital converter for performing the one or more voltage measurements.

[0183] Various aspects have been described in this disclosure. These and other aspects are within the scope of the following claims.

Claims

1. A circuit comprising a driver circuit, the driver circuit being configured to control a power switch circuit, the power switch circuit comprising a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch: wherein the driver circuit is configured to deliver a modulation signal to a control node of the power switch to control on / off switching of the power switch, wherein the driver circuit is configured to perform current measurements and voltage measurements associated with the temperature-dependent circuit element and to control the power switch based at least in part on the current measurements and the voltage measurements, and wherein the current measurement and the voltage measurement are performed based on a timing associated with the on / off switching of the power switch, The current measurement and the voltage measurement are paired measurements. 2 . The circuit of claim 1 , wherein the current measurement and the voltage measurement are performed when a voltage across the power switch is stable and the power switch is not in a transition state. 3 . The circuit of claim 2 , wherein the current measurement and the voltage measurement are performed when the power switch is turned on.

4. The circuit of claim 2, wherein the current measurement and the voltage measurement are performed when the power switch is off, and wherein the driver circuit is configured to apply a negative voltage to the control node during the current measurement and the voltage measurement. 5 . The circuit of claim 1 , wherein the driver circuit comprises logic configured to control the power switch in response to the current measurement and the voltage measurement indicative of a temperature of the power switch. 6 . The circuit of claim 5 , wherein the logic is configured to adjust a transition speed of the power switch in response to the current measurement and the voltage measurement indicative of the temperature of the power switch. 7 . The circuit of claim 5 , wherein the logic is configured to disable the power switch in response to the current measurement and the voltage measurement being indicative of the temperature of the power switch.

8. The circuit of claim 5, wherein the logic is configured to control the power switch in response to a calculation of an impedance indicative of the temperature of the power switch, wherein the calculation of the impedance is based on the current measurement and the voltage measurement. 9 . The circuit of claim 1 , wherein the driver circuit comprises a temperature unit configured to determine a temperature of the power switch based on the current measurement and the voltage measurement.

10. The circuit of claim 9, wherein the circuit further comprises a control unit configured to adjust the modulation signal based on the determined temperature. 11 . The circuit of claim 1 , wherein the driver circuit is configured to perform the current measurement and the voltage measurement during a same switching period of the power switch. 12 . The circuit of claim 1 , wherein the driver circuit is configured to perform the current measurement and the voltage measurement a plurality of times within each switching period of the power switch.

13. The circuit of claim 1, wherein the driver circuit is configured to perform at least one current measurement and a plurality of voltage measurements within a same switching period of the power switch.

14. A method of controlling a power switch circuit, the power switch circuit comprising a power switch and a temperature-dependent circuit element, the temperature-dependent circuit element being electrically coupled to at least one node of the power switch, the method comprising: Delivering a modulation signal to a control node of the power switch to control on / off switching of the power switch; performing a current measurement associated with the temperature dependent circuit element; performing a voltage measurement associated with the temperature dependent circuit element; as well as controlling the power switch based at least in part on the current measurement and the voltage measurement, The performing of the current measurement and the voltage measurement comprises: The current measurement and the voltage measurement are performed in pairs.

15. The method according to claim 14, further comprising: The current measurement and the voltage measurement are performed according to a timing sequence based on a timing associated with the on / off switching of the power switch.

16. The method of claim 15, wherein controlling the power switch comprises: The power switch circuit is controlled in response to the current measurement and the voltage measurement indicative of a temperature of the power switch.

17. The method according to claim 15, further comprising: An impedance is calculated based on the current measurement and the voltage measurement, and the power switch is controlled based on the calculated impedance.

18. The method according to claim 15, further comprising: determining a temperature of the power switch based on the current measurement and the voltage measurement, Wherein controlling the power switch includes: adjusting the modulation signal via a controller based on the determined temperature.

19. The method of claim 14, wherein performing the current measurement and the voltage measurement in the paired manner comprises: The current measurement and the voltage measurement are performed during a same switching period of the power switch.

20. A circuit device comprising: a power switch circuit comprising a power switch and a temperature-dependent circuit element electrically coupled to at least one node of the power switch; as well as a driver circuit configured to deliver a modulated signal to a control node of the power switch to control on / off switching of the power switch, wherein the driver circuit is configured to perform current measurements and voltage measurements associated with the temperature-dependent circuit element and control the power switch based at least in part on the current measurements and the voltage measurements, and wherein the current measurement and the voltage measurement are performed based on a timing associated with the on / off switching of the power switch, The current measurement and the voltage measurement are paired measurements.

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