Temperature detection using modulation of drive output impedance of power switch

Abstract

Embodiments of the present disclosure relate to temperature detection of a power switch using modulation of a driver output impedance. The present disclosure relates to circuits and techniques for detecting or responding to a temperature of a power switch. A driver circuit for a power switch can be 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 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.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to power switches, and more specifically to techniques and circuits for detecting temperature in a power switch circuit. BACKGROUND

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

[0003] Power switches are typically controlled via a modulated 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 modulated control signals. The modulated 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 through the power switch to a load. The on / off switching of the power switch effectively divides its power delivery into discrete portions. The average of the voltage and / or current fed to the load can be controlled by rapidly turning the switch on and off. The longer the period of time that the switch is on compared to the period of time that the switch is off, the higher the total power provided to the load. In many applications, two different power switches are configured in a high-side and low-side configuration, and the on / off switching of the two power switches is synchronized in order to deliver a desired power to a switch node located 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 a negative temperature coefficient (NTC) thermistor or a semiconductor-based temperature sensor (e.g., a diode) mounted in the vicinity of the power switch. These external components can be electrically isolated from the power switch in order to simplify the measurements. Unfortunately, these conventional techniques can not be accurate and can result in a delayed reaction to temperature-related problems with the switch. For example, the external components can measure the temperature of the housing of the switch or the temperature in the vicinity of the switch with some inherent delay, but these measurements do not always accurately indicate the temperature of the power switch itself. SUMMARY

[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 temperature. The power switch circuit can 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 can be electrically coupled to at least one node of the power switch. A driver circuit for the power switch can be configured to perform useful techniques that facilitate accurate temperature detection. Moreover, a variety of driver control techniques are described for controlling the power switch in response to the temperature detection. The control techniques can include local control techniques that can be implemented in logic of the driver circuit, e.g., to disable the power switch or adjust a transition time of the power switch. Additionally or alternatively, the control techniques can include system-level control techniques that can be implemented by a controller of the driver circuit, e.g., to adjust a modulation control signal delivered to the power switch.

[0006] In some examples, the present disclosure describes techniques that perform paired measurements of both current and voltage to facilitate accurate temperature determination associated with a power switch. In such examples, the current and voltage measurements can be performed based on timing associated with on / off switching of the power switch. For example, the current and voltage measurements can be performed at a particular time when voltage on the power switch is stable and the power switch is not in a transition state. The measurements can be paired in that both the current and voltage measurements are proximate to each other in time, e.g., within a time window in which temperature in the power switch is unlikely to change, or within a time window in which voltage does not change significantly between two current measurements (or vice versa). In some examples, the current and voltage measurements can be made 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 and voltage measurements can be made periodically at precise times within different switching periods of the power switch. The voltage and current measurements can facilitate a calculation of an 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 be indicative of a 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 the current and voltage measurements. Again, several different control techniques are described.

[0007] In other examples, the present disclosure describes techniques in which the 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 within 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 particular time when the voltage across 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 while the power switch is stable, the driver circuit can be configured to calculate the input impedance of the temperature-dependent circuit element coupled to the node of the power switch based on the one or more voltage measurements and a known ratio at the time the output impedance of the driver circuit is modulated. The input impedance of the temperature-dependent circuit can be indicative of 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 the one or more voltage measurements. Again, several different control techniques are 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 modulation 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 a current measurement and a voltage measurement associated with the temperature-dependent circuit element and control the power switch based at least in part on the current measurement and the voltage measurement. The current measurement and the voltage measurement are performed based on timing associated with the on / off switching of the power switch.

[0009] In another example, the present disclosure describes a method of controlling 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 method includes 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, and controlling the power switch based at least in part on the current measurement and the voltage measurement.

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

[0011] In another example, the disclosure describes a circuit configured to control a power switching circuit including a power switch and a 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 supply circuit, where 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 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.

[0012] In another example, the disclosure describes a method of controlling a power switching circuit including a power switch and a 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 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.

[0013] In another example, a circuit apparatus includes a power switching circuit including a power switch and a temperature-dependent circuit element electrically coupled to at least one node of the power switch, and a driver circuit 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] These and other examples are set forth in the detailed description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF 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 can be used to modulate an output impedance of the driver circuit in accordance with one or more techniques of the present disclosure;

[0019] Figure 5 is another block diagram of an example circuit arrangement 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 with a low-side driver circuit and a high-side power switch with a high-side driver circuit;

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

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

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

[0024] Figure 10 and 11 are flowcharts of temperature sensing and control techniques consistent with the present disclosure using paired voltage and current measurements; and

[0025] Figure 12 and 13 are flowcharts of temperature sensing and control techniques consistent with the present disclosure using modulation of a driver output impedance and one or more voltage measurements. DETAILED DESCRIPTION

[0026] Figure 1 is a block diagram of an example circuit arrangement 100 including a power switch circuit 104 and a driver circuit 102 having temperature-dependent control. The power switch circuit 104 can 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 can include a temperature-dependent resistor coupled between a control node and an output node of the power switch 108. The driver circuit 102 is one 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 a power switch in response to detection of temperature.

[0027] In some examples, the driver circuit 102 can be configured to perform paired measurements of 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 examples, the driver circuit 102 can be configured to perform current and voltage measurements based on timing associated with on / off switching of the power switch 108. For example, the current and voltage measurements can be performed at a particular 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 and voltage measurements are proximate to each other in time, e.g., 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 and voltage measurements within the same switching period of the power switch 108, although in other examples, the paired measurements can also span multiple switching periods. Further, in some cases, the paired measurements can 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, the paired measurements can be taken in response to a trigger or command from a control circuit. In any case, the voltage and current measurements can facilitate calculation of an 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 can be indicative of the temperature of the power switch 108. In various examples, the driver circuit 102 can also be configured to control the power switch 108 based at least in part on the current and voltage measurements. Again, several different control techniques are also described below.

[0028] In other examples, the driver circuit 102 can 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 one or more voltage measurements can 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 one or more voltage measurements can be performed at a particular time when the voltage across the power switch 108 is stable and the power switch 108 is not in a transition state. Further, in some cases, modulating the output impedance of the driver circuit 102 and performing one or more voltage measurements can be repeated within successive switching periods of the power switch, for example, 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 one or more voltage measurements can be made in response to a trigger or command from the control circuit. In any case, by modulating (e.g., adjusting or reconfiguring) the output impedance of the driver circuit 102 at a time 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 the one or more voltage measurements and a known ratio at the time the output impedance of the driver circuit 102 is modulated. The input impedance of the temperature-dependent circuit 106 can be indicative of a temperature, thereby providing a measurement 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. Again, several different control techniques are described below.

[0029] Figure 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 can 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 can include, but are not limited to, a junction field effect transistor (JFET), a metal oxide semiconductor FET (MOSFET), a dual-gate MOSFET, an insulated gate bipolar transistor (IGBT), any other type of FET, or any combination thereof. Examples of MOSFETs can include, but are not limited to, a PMOS, an NMOS, a DMOS, or any other type of MOSFET, or any combination thereof. Examples of BJTs can include, but are not limited to, a PNP, an NPN, a heterojunction, or any other type of BJT, or any combination thereof.

[0030] Power control circuitry 204 may include a control terminal 201 for providing a modulated control signal for switching power switch 205 on / off. Terminals 202 and 203 are designated as load terminals, provided a load can be attached to either terminal 202 or terminal 203, depending on the use and configuration of power switch circuitry 204 within the larger system. Depending on the load configuration and location, current flows from terminal 202 through power switch 205 to terminal 203, or from terminal 203 through power switch 205 to terminal 202. A modulated control signal from driver circuitry may be delivered to control terminal 201 to control the on / off switching of power switch 205, thereby delivering current to the load. In the MOSFET example, control terminal 201 may include a gate, load terminal 202 may include a drain, and load terminal 203 may include a source. In the BJT example, control terminal 201 may include a base, load terminal 202 may include a collector, and load terminal 203 may include an emitter. In some cases, an additional gate resistor 208 (or the base resistor in the BGT example) 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 may be located between the control node and the load node of the power switch 205 to provide a current path in parallel with the current path through the power switch 205 from terminal 202 to terminal 203 (and vice versa). According to this disclosure, the driver circuit for the power switch 205 ( Figure 2 (Not shown) A useful technique can be configured to perform accurate temperature detection of the temperature-dependent circuit element 206, which can provide an accurate indication of the temperature of the power switch circuit 204. Furthermore, various driver control techniques for controlling the power switch in response to temperature detection are described.

[0032] Figure 3 This is a block diagram of an example circuit arrangement 300 including a power switching 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 the necessary power to the driver circuit 302.

[0033] The driver circuit 302 can 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, which is electrically coupled to at least one node of the power switch 302.Figure 2 An example of a power switch circuit 204 that can correspond to the power switch circuit 304 of Figure 3 Generally, the driver circuit 302 can include a driver 312 configured to deliver a modulation signal to a control node of the power switch 308 in order to control on / off switching of the power switch 308. In addition, the driver circuit 302 includes a current sense unit 314 configured to perform current measurements and a voltage sense unit 316 configured to perform voltage measurements. The current and voltage measurements performed by the current sense unit 314 and the voltage sense unit 306 can include measurements associated with temperature-dependent circuit elements, and the measurements can be paired in that the current and voltage measurements are close in time, e.g., within a time window in which the temperature of 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 and voltage measurements are performed by the current sense unit 314 and the voltage sense unit 306 within the same switching period of the power switch 308, but in other examples, the paired measurements can also span multiple switching periods. Thus, at times, the paired measurements can be based on extrapolation or known behavior of the circuit, even if the measurements span two or more switching periods. In addition, in certain cases, the paired measurements can be performed periodically, e.g., every switching period or every “Nth” switching period, where N is a positive integer. Furthermore, in some cases, the paired measurements can be performed in response to a trigger or command from a controller (not shown) to the driver circuit 302. In any case, based on the voltage and current measurements, the driver circuit 312 can be configured to calculate an input impedance of the temperature-dependent circuit element 306, and this input impedance of the temperature-dependent circuit element 306 can be indicative of a 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 and voltage measurements. In some cases, the driver circuit 312 can control or regulate operation of the power switch based on the calculated impedance, and in some cases, an additional step can be performed by mapping the calculated impedance to an actual temperature, in which case the calculated temperature can be used in the control scheme. Either case can result in a desired control of the power switch 308 that is responsive or adaptive to temperature. Figure 3

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

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

[0036] In some examples, the voltage sense unit 316 can be used to measure the voltage of the control node of the power switch 308 if the temperature dependent circuit element 306 is connected to the control node. In some examples, the voltage sense unit 316 can be used to measure the voltage of the power supply unit 315 if the voltage drop across the unit 312 between the output of the power supply unit 315 and the control node of the power switch is known or close to 0. In other examples, the voltage sense unit 316 can be used to measure the voltage at the terminal of the temperature dependent circuit element 306 if the other terminal of the element 306 is connected to the load terminal of the power switch 308.

[0037] Various 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 and voltage measurements indicating the temperature of the power switch. Figure 3 (Not shown in the diagram). For example, driver 312 can be configured to respond to one or more temperature-dependent changes in the operation of the power switch circuit. For example, the logic can be configured to adjust the switching speed of power switch 308 in response to current and voltage measurements indicating the temperature of power switch 308. As another example, the logic can be configured to disable power switch 308 in response to current and voltage measurements indicating the temperature of power switch 308, which can provide device protection. Disabling power switch 308 can include turning off the power switch, and in some cases, disabling power switch 308 can also include preventing power switch 308 from being turned on. As mentioned above, in some cases, the circuit response can occur based on the calculation of the impedance (e.g., the input impedance of temperature-dependent circuit element 306) indicating the temperature of power switch 308. Therefore, in some examples, the logic in driver circuit 302 ( Figure 3 (Not shown) can be configured to control power switch 308 in response to an impedance calculation indicating the temperature of power switch 308, wherein the impedance calculation is based on current and voltage measurements.

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

[0039] The power switch 308 can comprise 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 located between the high-side power switch and the low-side power switch. The techniques of the present disclosure can be used for temperature detection and control of the high-side power switch, the low-side power switch, or both the high-side power switch and the low-side power switch. In further examples, a control unit (e.g., a digital control unit) can be used to control the driver 312 and possibly deliver commands or triggers to initiate voltage measurements and current measurements for temperature detection. In addition, the present disclosure describes configurable parameters that can be used to configure the driver circuit 302, the control unit, or other units. Additional details of example control units, configurability, and other aspects of temperature detection techniques are described in more detail below.

[0040] As noted above, the temperature-dependent circuit element 306 can comprise a temperature-dependent resistor, although other types of temperature-dependent circuit elements can also be used in accordance with the present disclosure. In some cases, the temperature-dependent circuit element 306 is electrically coupled to a control node of the power switch 308 and a load node of the power switch 308 (e.g., as shown in the example power switch circuit 204 of FIG. 2, between the node coupled at Gint and the node at E). However, in other examples, the temperature-dependent circuit element 306 can be electrically coupled to a dedicated sense node (which can comprise a dedicated sense pin) associated with the power switch circuit 304 and a load node of the power switch 308. Figure 2

[0041] Figure 4 is a block diagram of an example circuit arrangement 400 comprising a driver circuit 402 that includes a driver 412 comprising 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 in order to facilitate accurate temperature measurements based on a known ratio between voltages associated with the high-ohmic path 418, e.g., by reference to 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 each construction), the impedance of the temperature-dependent circuit element 406 can be calculated by measuring the voltage at the 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 voltage 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 the temperature calculation. In this case, the path through the gate driver can be configured as an ohmic path that 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) that refer to at least one reference voltage, and the ratio can be calculated based on the conversion results. In another implementation, the voltage at the power supply 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 referred to as ratiometric, and provides the ratio between the two voltages with one AD conversion. In this case, the result is always “paired” because the ADC considers both voltages at the same time. If these measurements are made in a teaching phase, for example on a test equipment during production testing at different temperatures, the conversion results can be directly used as input for a LUT without the need to know or trim the value of the high ohmic path. The low ohmic path can be used to control the control node of the power switch during transitions between the switching states of the power switch and to control the transition itself (e.g. switching speed). The low ohmic path can be constructed in a way that ensures that the voltage measurement on the low ohmic path does not deliver a measurement that is precise enough for the temperature calculation (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 in order to make a more precise voltage measurement because the voltage drop over the high ohmic path is larger than the voltage drop over the low ohmic path (in steady state).

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

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

[0045] In some cases, the voltage sensing unit 416 can perform one or more voltage measurements at the output of the driver 412, and the driver circuit 402 can 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 way, the driver circuit 402 can be configured to calculate the input impedance of the temperature-dependent circuit element 406 based on one or more voltage measurements of the voltage sensing unit 416 and a known ratio in modulating the output impedance of the driver circuit. The low-ohmic path 417 can include a normal electrical path used in delivering control signals to the power switch 408, while the high-ohmic path 418 can 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 a known ohmic ratio defined by the high-ohmic path 418. A network of one or more resistors can be used to define the high-ohmic path 418, but other components can also be used to modulate the output impedance of the driver 412. For example, other components that can be used for such output impedance modulation can 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 timing associated with the on / off switching of the power switch. In some examples, 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 when the power switch 408 is stable and the power switch 408 is not in a transition state. In some examples, the driver 412 can determine that the voltage on the power switch 408 is stable based on determining that the driver 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 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 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, the voltage sensing unit 416 can be configured to suppress sensing when the power switch 408 is not stable or is operating in a transition state.

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

[0048] Similar to the example of Figure 3 In the example of Figure 4 In response to the temperature detection, a variety of driver control techniques can be used to control the power switch 408. In some examples, the driver circuit 402 includes logic (not shown in Figure 4 For example, the driver 412 can be configured to respond to one or more temperature-related changes in operation of the power switch circuit 404. For example, the logic can be configured to adjust a transition speed of the power switch 408 in response to one or more voltage measurements (and known ratios or impedances) indicative of a 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) indicative of a 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 the high-ohmic path indicative of a temperature of the power switch 408. Thus, in some examples, the logic (not shown in Figure 4

[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. Furthermore, in some examples, the voltage sensing unit 416 of the driver circuit 402 can be configured to perform multiple voltage measurements 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). Additionally, in some cases, the voltage sensing unit 416 of the driver circuit 402 can be configured to respond to a signal from the control unit (…). Figure 4 (not shown) commands or triggers to perform one or more voltage measurements.

[0050] Similar to Figure 3 In the example, Figure 4 In some examples, 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 switching node located between the high-side and low-side power switches. The techniques disclosed herein can be used for temperature detection and control of the high-side power switch, the low-side power switch, or both the high-side and low-side power switches. In other examples, a control unit (e.g., a digital control unit) may be used to control driver 412 and may deliver commands or triggers to initiate output impedance modulation and voltage measurement for temperature detection. Furthermore, this disclosure describes configurable parameters that can be used to configure driver circuitry 402, control unit, or other units. Additional details regarding exemplary control units, configurability, and other aspects of 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 according to this disclosure. In some cases, temperature-dependent circuit element 406 is electrically coupled to the control node of power switch 408 and the load node of power switch 408 (e.g., such as...). Figure 2 As shown in the example power switch circuit 204, the node is coupled between the node at Gint and the node at E. However, in other examples, the temperature-dependent circuit element 406 may be electrically coupled to a dedicated sensing node associated with the power switch circuit 404 and the load node of the power switch 408.

[0052] Figure 5 This is another block diagram of an example circuit device capable of performing paired voltage and current measurements. Circuit device 500 includes a power switching circuit 504, which may be similar to... Figure 2The illustrated circuit power switch circuit 204. The circuit device 500 also includes a control unit 522, which can include a digital processing unit such as a microprocessor, ASIC, FPGA, CPLD, or microcontroller. In addition, the circuit device 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 sense unit 514. In some examples, the units 512, 520, 524, 526, 516, and 514 can be part of a gate driver circuit, although one or more of these units can also be implemented as separate circuits, or part of the control unit 522.

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

[0054] In some examples, the current measurements and voltage measurements performed by the voltage and current sense unit 514 are within the same switching period of the power switch within the power switch circuit 504, although in other examples, the paired measurements can also span multiple switching periods. In addition, in some cases, the paired measurements can be performed periodically by the voltage and current sense unit 514, 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 results of several paired measurements to reduce noise effects or distortion of individual measurements.

[0055] The synchronization unit 524 can 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 can receive signals (or a mirror of the signals) associated with the PWM control signals from the control unit 522, which are also delivered to the gate driver 512. In this way, the synchronization unit 524 can identify the time at which the power switch within the power switch circuit 504 is stable to trigger the paired measurements by the voltage and sense unit 514. The temperature function unit 516 can determine a 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 across and through the temperature dependent circuit element. In some cases, the calculated impedance can be used as an indicator of temperature itself, while in other cases, the calculated impedance can be mapped to a temperature, such as via a mathematical equation or a lookup table (LUT). In any case, the temperature function unit 516 can provide an indication of temperature to the 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. 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 the power switch within the power switch circuit 504 in response to the temperature, or possibly adjusting (increasing or decreasing) the transition time associated with the power switch in response to the measured temperature, or changing the timing and / or level of the current or voltage to charge or discharge the 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 noted above, the decision unit 526 can also be configured to cause a system-level reaction to the temperature. The system-level reaction can include adjusting the PWM control signal, for example, adjusting the duty cycle, based on the measured temperature. The driver-level reaction can be more sensitive to temperature variations, providing circuit protection based on the temperature or operating conditions of the power switch. The system-level reaction helps to 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 timing associated with on / off switching of the power switches within the power switch circuit 504, the measurement being controlled by a 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 voltage measurement can be performed at a particular time when the voltage across the power switches within the power switch circuit 504 is stable and the power switches are not in a transition state. Further, at other times when the power switches within the power switch circuit 504 are unstable or operating in a transition state, the voltage and current sensing unit 514 can refrain from sensing. Also, the voltage measurement and current measurement can be so-called “paired measurements” of current and voltage in that the current measurement and voltage measurement are proximate to each other in time, e.g., within a time window in which the temperature in the power switch circuit 504 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 voltage and current sensing unit 514 can be configured to perform the current measurement and voltage measurement within the same switching period of the power switches within the power switch circuit 504, although in other examples, the paired measurements can also span multiple switching periods. Further, in some cases, the paired measurements can be repeated within consecutive switching periods of the power switches, e.g., every period or every “Nth” period, where N is a positive integer. In other cases, the paired measurements can be taken in response to a trigger or command from the control unit 522. In some cases, a user can be able to cause the control unit 522 to initiate the trigger in order to provide the user with the ability to measure the temperature of the power switch circuit 504 when desired.

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

[0060] The first gate driver 612 delivers a modulated control signal to a high-side power switch within the power switch circuit 604, while the second gate driver 642 delivers a modulated control signal to a low-side power switch within 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. Gate driver power supplies 620 and 640 can provide the power needed to operate the gate drivers 612 and 642.

[0061] On the high-side, the gate driver 612 can be configured to control a power switch within the power switch circuit 604. Specifically, the gate driver 612 is configured to deliver a modulated signal to a 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-dependent circuit elements within the power switch circuit 604. As described herein, these voltage measurements and current measurements can be paired and timed according to switching periods associated with the on / off switching of the power switch within the power switch circuit 604. Moreover, the timing of the voltage measurements and current measurements on the high-side via the voltage and current sensing unit 614 can be coordinated relative to the timing of the voltage measurements and current measurements on the low-side via the voltage and current sensing unit 648.

[0062] On the low-side, the gate driver 642 can be configured to control a power switch within the power switch circuit 654. Specifically, the gate driver 642 is configured to deliver a modulated signal to a 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-dependent circuit elements within the power switch circuit 654. As described herein, these voltage measurements and current measurements can be paired and timed according to switching periods associated with the on / off switching of the power switch within the power switch circuit 654. Moreover, the timing of the voltage measurements and current measurements on the low-side via the voltage and current sensing unit 648 can be coordinated relative to the timing of the voltage measurements and current measurements on the high-side via the voltage and current sensing unit 614.

[0063] Again, in accordance with the present disclosure, the current measurement and voltage measurement performed by voltage and current sense unit 614 on the high side can include a pair measurement. Similarly, the current measurement and voltage measurement performed by voltage and current sense unit 648 on the low side can include a pair measurement. Moreover, in some cases, the pair measurement can be taken periodically by voltage and current sense units 614 and 648, such as every other switching period or periodically. In some cases, voltage and current sense units 614 and 648 can perform sensing in a complementary manner, such as voltage and current sense unit 614 operating for one switching period and voltage and current sense unit 648 operating for another (different) switching period, or voltage and current sense unit 614 operating for a portion or phase of a switching period and voltage and current sense unit 648 operating for another (different) portion or phase of a switching period.

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

[0065] On the high side, impedance function unit 636 can determine an impedance of the first temperature dependent circuit element having power switch circuit 604 based on the pair of 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 across and current through the temperature dependent circuit element. Similarly, on the low side, impedance function unit 650 can determine an impedance of the second temperature dependent circuit element having power switch circuit 654 based on the pair of current measurement and voltage measurement.

[0066] The impedance calculated by impedance function units 636 and 648 can be used as an indicator of temperature. Accordingly, impedance function units 636 and 648 can provide a signal indicative of the impedance calculation to local decision units 630 and 646, respectively. Local decision units 630 can control logic within gate driver 612 for the high side to provide an immediate driver reaction to temperature. In some cases, the logic within gate driver 612 can react to temperature related changes in the operation of the circuitry of the high side (e.g., due to high temperatures) by causing gate driver 612 to disable power to the power switches within power switch circuit 604 or adjust the transition times of the power switches within power switch circuit 604. Similarly, the logic within gate driver 642 can react to temperature related changes in the operation of the circuitry of the low side (e.g., due to high temperatures) by causing gate driver 642 to disable power to the power switches within power switch circuit 654 or adjust the transition times of the power switches within power switch circuit 654.

[0067] In addition, impedance function units 636 and 648 can provide a signal indicative of the impedance calculation to temperature function units 634 and 652, respectively. Temperature function units 634 and 652 can apply a mathematical function or a look up table (LUT) in order to calculate a temperature based on the measured impedance. The contents of the LUT can be populated with calculated values or can be populated with values detailed during reference measurements using known temperatures. The temperature indication can be delivered from temperature function units 634 and 652 (associated with the high side and low side switches, respectively) to system decision criteria unit 632. System decision criteria unit 632 can then provide a signal to control unit 622 for system level reactions, such 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, control unit 622 can adjust the PWM signal for first gate driver 612, second gate driver 642, or both gate drivers 612, 642 based on the calculated temperature. In some examples, temperature function units 634 and 652 can also be eliminated, in which case control unit 622 can be configured to adjust the modulation signal based on the determined impedance determined by impedance function units 636 and 650. However, from a digital perspective, it is often desirable to program control unit 822 in the temperature domain (rather than the impedance domain), even though the calculated input impedance of temperature related circuit elements can be mathematically related to temperature.

[0068] In some examples, various units within the circuit arrangement 600 can be configurable, e.g., to configure one or more configurable parameters that define a response of the circuit operation to temperature. For example, the configuration unit 644 (which can be an external programming unit) can be able to configure local reaction thresholds defined by the local decision criteria units 630 and 646. Alternatively or additionally, the configuration unit 644 can be able to configure temperature functions within the temperature function units 634 and 652, such as by defining or configuring a lookup table based on testing. Further, in some examples, the configuration unit 644 can be able to define one or more system reaction thresholds for the system decision criteria unit 632, such as by defining a temperature threshold at which a PWM signal should be adjusted, for example. For example, various configurable parameters can be derived from testing (e.g., during one or more production tests) and possibly stored in memory associated with the units or controller, such as 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 measurements based on a known ratio of voltages associated with the high-ohmic path 742.

[0070] The gate driver circuit 702 can 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 the power switch circuit 204 are provided that are similar to the power switch circuit 704.

[0071] The gate driver circuit 702 can be configured to be coupled to a gate driver supply circuit 720, and the gate driver circuit 702 can be configured to deliver a modulation signal to a control node of the power switch within the power switch circuit 704 to control on / off switching of the power switch. Further, the gate driver circuit 702 can 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 can be positioned between the gate driver circuit 702 and the power switch circuit 704. For example, the external gate resistor 730 can 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 switches 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 voltage sensing by controlling the switches 713A and 713B and providing signals to the voltage check / measurement unit 734. To modulate the output impedance of the gate driver circuit 702 at the control node of the power switches within the power switch circuit 704, the gate driver circuit 702 can include a low-ohmic path 744 from the gate driver supply 720 to the control node of the power switches within the power switch circuit 704 and a high-ohmic path 742 from the gate driver supply 720 to the control node. The 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 the 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 voltage sensing during such modulation) occurs at the appropriate time within the PWM period in which the power switches are stable. 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 an input impedance of a temperature-dependent circuit element within the power switch circuit 704. In this way, the gate driver circuit 702 can be configured to calculate an input impedance of a temperature-dependent circuit element within the power switch circuit 704 based on one or more voltage measurements of the voltage check measurement unit 734 and a ratio in modulating an output impedance of the gate driver circuit 702. The low-ohmic path 744 can include a normal electrical path used in delivering a control signal to the power switch circuit 704, while the high-ohmic path 742 can include an alternative path having 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 a measured voltage and a 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 an output impedance of the gate driver circuit 702. For example, other components that can be used for such output impedance modulation can 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 a timing associated with a turn-on / turn-off switching of the power switch. In some examples, 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 when the power switch within the power switch circuit 704 is stable and the power switch is not in a transition state. In some examples, the gate driver can determine that a driver supply voltage from the gate driver supply 720 is stable. In some examples, the voltage check measurement unit 734 can coordinate impedance modulation and voltage sensing based on a 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 turned 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 suppress 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 the low-ohmic path 744 to a state defining the high-ohmic path 742 and perform one or more voltage measurements multiple times within one switching period of the power switch. In other cases, the gate driver circuit 702 can be configured to modulate from a state defining the low-ohmic path 744 to a state defining the 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. Further, in other cases, the gate driver circuit 702 can be configured to modulate from a state defining the low-ohmic path 744 to a state defining the high-ohmic path 742 and perform one or more voltage measurements in response to a command or trigger from a control unit (not shown in FIG. 7). In some cases, the voltage check measurement unit 734 can include an analog-to-digital converter (ADC) or an analog amplifier or an analog comparator. Figure 7

[0076] The result reaction unit 736 can generally represent any one of a variety of driver control techniques that can be used to control the 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 the power switch within the power switch circuit 704 in response to one or more voltage measurements and a known ratio indicative of a temperature of the power switch. For example, the unit 736 can be configured to respond to one or more temperature-related changes in operation of the power switch circuit 704. For example, the logic can be configured to adjust a transition speed of the power switch within the power switch circuit 704 in response to one or more voltage measurements (and a known ratio) indicative of a temperature of the power switch. As another example, the logic can be configured to disable the power switch within the power switch circuit 704 in response to one or more voltage measurements (and a known ratio) indicative of a temperature of the power switch, which can provide device protection. Disabling the power switch can include turning off the power switch, and in some cases, disabling the power switch can also include preventing the power switch from turning on. As noted above, in some cases, the circuit response can occur based on a calculation of an impedance (e.g., an input impedance of a temperature-dependent circuit element within the power switch circuit 704) indicative of a temperature of the power switch within the power switch circuit 704. Thus, in some examples, the logic within the unit 736 can be configured to control the power switch in response to a calculation of an impedance indicative of a temperature of the power switch, where the calculation of the impedance is based on the voltage measurements and the known ratio associated with the high-ohmic path 742. In further examples, 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 for system-level response to the temperature. In such cases, the control unit can be configured to control the power switch in response to the calculation of the impedance.​Figure 7 The PWM signal (e.g., duty cycle) can be adjusted based on temperature, which can be sent via a signal from the cell 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 a power switch within the power switch circuit 704. Further, in some examples, the voltage check measurement unit 734 of the gate driver circuit 702 can be configured to perform a voltage measurement multiple times within each switching period of a 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 an individual 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 consecutive switching periods (e.g., every period or every Nth period). Further, 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 a power switch within the power switch circuit 704 is unstable or in a transition state.

[0078] Figure 8 is another example of a block diagram consistent with the techniques of the present disclosure and including both a low-side power switch circuit with a low-side gate driver circuit and a high-side power switch with a high-side driver circuit. Figure 8 The example of includes a first power switch circuit 804 and a second power switch circuit 854, which can be referred to as high-side and low-side power switch circuits. A switching node between the first power switch circuit 804 and the second power switch circuit 854 delivers power to a load based on on / off switching of 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 modulated control signal to a high-side power switch within the power switch circuit 804, while the second gate driver 842 (which includes the ability to modulate to a high-ohmic path) delivers a modulated control signal to a low-side power switch within the power switch circuit 854. The control unit 822 can deliver PWM commands to the gate drivers 804 and 842 to coordinate 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 of less than 10 ohms. Gate driver power supplies 820 and 840 can provide the power needed to operate the gate drivers 812 and 842.

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

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

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

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

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

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

[0086] In addition, impedance function units 836 and 848 can provide a signal indicative of the impedance calculation to temperature function units 834 and 852, respectively. Temperature function units 834 and 852 can apply a mathematical function or a look up table (LUT) in order to calculate a temperature based on the measured impedance. For example, the contents of the LUT can be populated with calculated values, or can be populated with values detailed out during reference measurements using known temperatures. The temperature indication can be delivered from temperature function units 834 and 852 (associated with the high side and low side switches, respectively) to system decision criteria unit 832. System decision criteria unit 832 can then provide a signal to control unit 822 for system level reactions, such 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, control unit 822 can adjust the PWM signal for first gate driver 812, second gate driver 842, or both gate drivers 812, 842 based on the calculated temperature. In some examples, temperature function units 834 and 852 can also be eliminated, in which case control unit 822 can be configured to adjust the modulation signal based on the determined impedance determined by impedance function units 836 and 850. However, from a digital perspective, it is often desirable to program control unit 822 in the temperature domain (rather than the impedance domain), even though the calculated input impedance of the temperature related circuit elements can be mathematically related to temperature. Likewise, if a LUT is used, the data within the LUT can be determined using calculated values, or can be defined using values detailed out during reference measurements using known temperatures.

[0087] As with circuit arrangement 600 of Figure 6 , the circuit arrangement 700 of FIG. 7A can be used to monitor the temperature of the circuit arrangement 700. In this case, the circuit arrangement 700 includes a first gate driver 712 and a second gate driver 742. The first gate driver 712 is configured to drive a first power switch circuit 704, and the second gate driver 742 is configured to drive a second power switch circuit 754. The first power switch circuit 704 is coupled to a first power supply 702, and the second power switch circuit 754 is coupled to a second power supply 752. The first power switch circuit 704 and the second power switch circuit 754 are coupled to a load 706. The first power switch circuit 704 and the second power switch circuit 754 are coupled to a common ground 708. Figure 8The various units within the circuit arrangement 800 can be configurable, e.g., to configure one or more configurable parameters that define a circuit operating response to temperature. For example, a configuration unit 844 (which can be an external programming unit) can be able to configure the local reaction thresholds defined by the local decision criteria units 830 and 846. Alternatively or additionally, the configuration unit 844 can be able to configure the temperature functions within the temperature function units 834 and 852, such as by defining or configuring a lookup table based on testing. Further, in some examples, the configuration unit 844 can be able to define one or more system reaction thresholds for the system decision criteria unit 832, such as by defining a temperature threshold at which the PWM signal should be adjusted, for example. The various configurable parameters can be derived from testing (e.g., during one or more production tests), and possibly stored in memory associated with the units or controller, such as one-time programmable (OTP) memory, flash memory, electrically erasable programmable read-only memory (EEPROM), or any type of volatile or non-volatile memory, for example.

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

[0089] Figure 9 is a timing diagram illustrating temperature sensing of a high-side and low-side switch (e.g., Figure 6 the power switch circuits 604 and 654 of FIG. 6, or Figure 8 the power switch circuits 804 and 854 of FIG. 8). Figure 9 is just one example, and many other timing sequences for temperature sensing can be used based on the on / off switching of the power switch, as described herein. In Figure 9In a specific example, Figure 901 illustrates the switching period of the high-side power switch, and Figure 902 illustrates the complementary switching period of the low-side power switch. For the high-side switch, temperature sensing Figure 903 illustrates sensing events 905A, 905B, and 905C. For the low-side switch, temperature sensing Figure 904 illustrates sensing events 906A, 906B, and 906C. In this example, temperature sensing events 905A, 905B, and 905C associated with the high-side switch are executed when the high-side switch is stable and on, and when the low-side switch is stable and off. Furthermore, in this example, temperature sensing events 906A, 906B, and 906C associated with the low-side switch are executed when the low-side switch is stable and on, and when the high-side switch is stable and off. In some examples, events 905A, 905B, and 905C may correspond to current sensing events and multiple voltage sensing events, and events 906A, 906B, and 906C may 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 high-side driver output impedance, and events 906A, 906B, and 906C may correspond to voltage sensing events corresponding to modulation of the low-side driver output impedance. Many other timing schemes can be used to provide sensing events for each switching period, to provide sensing events periodically every Nth switching period, to provide sensing events in response to a trigger or command, to provide sensing events across multiple switching periods, or to provide timing schemes based on the on / off switching of one or more power switches. Again, in some examples, filter structures can be used to filter the results of several pairs of measurements to reduce the noise effect or distortion of a single measurement.

[0090] Figure 10 and 11 These are two exemplary flowcharts consistent with this disclosure, employing temperature sensing and control techniques using paired voltage and current measurements. (From...) Figure 3 Angular description of the driver circuit 304 of the circuit device 300 in the middle. Figure 10 Although other circuits or circuit devices can also be used to perform this task. Figure 10 The technology. Figure 10 This 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, the temperature-dependent circuit element 306 being electrically coupled to at least one node of the power switch. For example... Figure 10As shown, driver 312 of driver circuit 302 delivers a modulation signal to a control node of power switch 308 to control on / off switching of power switch 308 (1001). Current sense unit 314 performs a current measurement associated with temperature dependent circuit element 306 (1002), and voltage sense unit 314 performs a voltage measurement associated with temperature dependent circuit element 306 (1003). The current and voltage measurements can be paired and can be performed based on the timing of the on / off switching of power switch 308, e.g., when power switch 308 is stable and not in a transition state. Driver circuit 312 can then control power switch 308 based at least in part on the current and voltage measurements (1004). In some examples, controlling the power switch can include controlling the power switch circuit in response to the current and voltage measurements indicative of a temperature of the power switch. In some examples, Figure 10 The method of Figure 10 may also include a step of calculating an impedance (e.g., an input impedance of temperature dependent circuit element 306) based on the current and voltage measurements, and controlling the power switch based on the calculated impedance. In some examples, Figure 10 The method of

[0091] Figure 11 is another flowchart of temperature sensing and control techniques using paired voltage and current measurements consistent with the present disclosure. It will be described from the perspective of circuit arrangement 600 in Figure 6 , although other circuits or circuit arrangements can also be used to perform the techniques of Figure 11 . Figure 1

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

[0093] ​In operation, the gate driver 612 delivers a modulation control signal to a control terminal of the power switch circuit 604, e.g., through an external gate resistor 621 (1102), which can control on / off switching of power switches within the power switch circuit 604. The voltage and current sensing unit 614 performs one or more voltage measurements based on the timing of the modulation signal (1104), and performs one or more current measurements based on the timing of the modulation signal (1105), which can define paired measurements for temperature determination and control. In Figure 11 In examples, logic within the local decision criteria unit 630 can be configured to disable operation of the power switches within the power switch circuit 604 if the measurements indicate a temperature-related change in circuit operation (1105). For example, the temperature-related change in circuit operation can be indicated by a high temperature, which can be defined or determined locally, e.g., by the driver circuitry, via impedance indications computed by the impedance function unit 636. For example, the computed impedance can include a measurement of input impedance of temperature- dependent circuit elements 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 response to impedance computation) can be faster than a system response in order to provide circuit and system protection against temperature changes in circuit operation. In addition to this immediate local response, Figure 11 The method of Figure 11 may also facilitate a system response to temperature, which can 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 based on the current and voltage measurements (1106), such as by applying a LUT to map the computed impedance to a temperature indication. Since the computed impedance is based on paired current and voltage measurements, the temperature indication is ultimately also based on paired measurements. In other examples, the computed impedance can also be used to elicit a system-level reaction, but can require use of temperature for system-level configuration, so can need to map the computed impedance to a temperature indication via the temperature function unit 634. The control unit 622 can then adjust the modulation signal based on the determined temperature (1107), e.g., by increasing or decreasing a duty cycle, which can in turn allow for predictive or preventative protection against temperature rise trends. These steps, as well as many other details described above, can also apply to the method shown in

[0094] Figure 12 and 13 are flowcharts of temperature sensing and control techniques using modulation of driver output impedance and one or more voltage measurements consistent with the present disclosure. It will be described from the perspective of the driver circuit 404 of the circuit arrangement 400 in Figure 4 Figure 12 ​Although other circuits or circuitry can be used to perform the techniques of Figure 12 . Figure 12 is one 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. As shown in Figure 12 , a driver 412 of a driver circuit 402 delivers a modulation signal to a control node of the power switch 408 to control on / off switching of the power switch 408 (1001). The driver 412 modulates its output impedance at the control node (1202), such as by switching from a low-ohmic path 417 to a high-ohmic path 418. The low-ohmic path 417 and the high-ohmic path 418 can 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 can 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, 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 timing associated with on / off switching of the power switch 408, when the power switch 408 is stable and the power switch 408 is not in a transition state.

[0095] The driver circuit 412 can control the power switch 408 based at least in part on the 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 an input impedance of the temperature-dependent circuit element 406, and that input impedance or voltage ratio can be indicative of a 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 the one or more voltage measurements (and ratios) indicative of a temperature of the power switch. In some examples, Figure 12 The method of Figure 12 may also include the steps of calculating an impedance (e.g., 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, Figure 12 The method of Figure 12 may also include the step of determining a temperature of the power switch based on the one or more voltage measurements, where controlling the power switch includes adjusting the modulation signal via the controller based on the determined temperature. Many of the other details described above can also apply to the method shown in

[0097] Figure 13 is another flowchart of temperature sensing and control techniques using modulation of the driver output impedance and one or more voltage measurements consistent with the present disclosure. The modulation of the output impedance of the gate driver 812 and the one or more voltage measurements performed by the voltage (ratio) sensing unit 814 will be described from the perspective of the circuit arrangement 800 in Figure 8 Figure 13 , although other circuits or circuit arrangements can be used to perform the techniques of Figure 13 .

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

[0099] In operation, the gate driver 812 delivers a modulation control signal to a control terminal of the power switch circuit 804 (1302), for example, through an 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 its output impedance to a high ohmic path in order to modulate the output impedance of the gate driver 812 at the control node of the power switch associated with the power switch circuit 804 (1303). While the gate driver 812 modulates its output impedance to a high ohmic path to define a high driver output impedance, the voltage (ratio) sensing unit 814 performs one or more voltage measurements based on the timing of the modulation signal (1304). The timing of the modulation of the output impedance of the gate driver 812 (1303) and the performance of the one or more voltage measurements (1304) can be based on the timing of the modulation control signal defining 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 the example of Figure 11 , in Figure 13 ​In the example of FIG. 8, the logic within the local decision criteria unit 830 can be configured to disable operation of the power switch within the power switch circuit 804 if the measurement indicates a temperature-related change in circuit operation (1305). For example, the temperature-related change in circuit operation can be indicated by a high temperature, which can be defined or determined locally (e.g., by the driver circuitry) via an impedance indication computed by the impedance function unit 836. For example, the computed impedance can include a measurement of an input impedance of a temperature-related 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 impedance computation) can be faster than a system response in order to provide circuit and system protection against temperature-related changes in circuit operation. In addition to this immediate local response, Figure 13 The method of FIG. 8 can also facilitate a system response to temperature, which can 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 based on the current measurement and the voltage measurement (1306), such as by applying a LUT to map the computed impedance or voltage ratio to a temperature indication. Since the computed impedance or voltage ratio is based on paired measurements, the temperature indication is ultimately also based on paired measurements. In other examples, the computed impedance or voltage ratio can also be used to cause a system-level reaction, but can require a system-level configuration using temperature, so the computed impedance or voltage ratio can need to be mapped to a temperature indication via the temperature function unit 834. The control unit 822 can then adjust the modulation signal based on the determined temperature (1107), for example, by increasing or decreasing the duty cycle, which can in turn allow for predictive or preventative protection against temperature rise trends. These steps, as well as many other details described above, can also apply to the method shown in FIG. 9. Figure 13

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

[0102] Example 1 - A circuit comprising a driver circuit configured to control a power switch circuit, the power switch circuit comprising a power switch and a temperature-related circuit element 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 a current measurement and a voltage measurement associated with the temperature-related circuit element and control the power switch based at least in part on the current measurement and the voltage measurement, 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. ​

[0103] Example 2 - The circuit of example 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.

[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 on.

[0105] Example 4 - The circuit of example 1 or 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.

[0106] Example 5 - The circuit of any of examples 1-4, wherein the current measurement and the voltage measurement are pair measurements.

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

[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 indicative of the temperature of the power switch.

[0113] Example 12 - The circuit of 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 comprises 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 an input to the lookup table is the current measurement and the voltage measurement.

[0117] Example 16 - The circuit of any of examples 1-14, further comprising a control unit configured to adjust the modulation signal based on the determined temperature.

[0118] Example 17 - The circuit of any of examples 1-16, wherein the driver circuit comprises 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 within a same switching period of the power switch.

[0123] Example 22 - The circuit of 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 - The circuit of 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 - The circuit of any one of Examples 1-23, wherein the power switch circuit comprises a high-side power switch circuit, the power switch comprises a high-side power switch, the temperature-dependent circuit element comprises a first temperature-dependent circuit element, the modulation signal comprises a high-side modulation signal, and the driver circuit comprises a high-side driver circuit, the circuit further comprising a low-side driver circuit configured to deliver a low-side modulation signal to a control node of a low-side power switch to control on / off switching of the low-side power switch, wherein the low-side driver circuit is further configured to perform current and voltage measurements associated with a second temperature-dependent circuit element and control the low-side power switch based at least in part on the current and voltage measurements associated with the second temperature-dependent circuit element.

[0126] Example 25 - The circuit of Example 24, wherein the current and voltage measurements 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 on, and one of the high-side switch and the low-side switch is off.

[0127] Example 26 - The circuit of Example 24 or 25, wherein the current and voltage measurements 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 on, and one of the high-side switch and the low-side switch is off.

[0128] Example 27 - 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 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; and controlling the power switch based at least in part on the current measurement and the voltage measurement.

[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 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 comprising determining a temperature of the power switch based on the current measurement and the voltage measurement, wherein controlling the power switch comprises adjusting the modulation signal via a controller based on the determined temperature.

[0133] Example 32 - The method of any of examples 27-31, wherein performing the current measurement and the voltage measurement comprises 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 paired manner 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 comprising configuring one or more parameters associated with controlling the power switch circuit, wherein the one or more parameters define one or more temperature-dependent functions associated with controlling the power switch.

[0136] Example 35 - A circuit arrangement 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; and a driver circuit 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 a current measurement and a voltage measurement associated with the temperature-dependent circuit element and control the power switch based at least in part on the current measurement and the voltage measurement, 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.

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

[0138] Example 37 - The circuit arrangement of 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 - The circuit arrangement of 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 - The circuit arrangement of any of examples 35-38, wherein the driver circuit comprises an analog-to-digital converter configured to perform the current measurement.

[0141] Example 40 - The circuit arrangement of any of examples 35-39, wherein the driver circuit comprises 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 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 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.

[0143] Example 42 - The circuit of example 41, wherein the driver circuit is configured to calculate an 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 - The circuit of example 41 or 42, wherein the driver circuit comprises: 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 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 an input impedance of the temperature dependent circuit element.

[0145] Example 44 - The circuit of 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 turn-on / turn-off switching of the power switch.

[0146] Example 45 - The circuit of 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 - The circuit of any of examples 41-45, wherein the one or more voltage measurements are performed when the power switch is turned on.

[0148] Example 47 - The circuit of 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 - The circuit of 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 one switching period of the power switch.

[0150] Example 49 - The circuit of any of examples 41-48, wherein the driver circuit comprises 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 of the lookup table is based on the one or more voltage measurements.

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

[0153] Example 52 - The circuit of any of examples 41-51, wherein the driver circuit comprises logic configured to control the power switch in response to the voltage measurements indicative of a 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 - The circuit of 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 - The circuit of 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 - The circuit of any of examples 41-58, wherein the power switch circuit comprises a high-side power switch circuit, the power switch comprises a high-side power switch, the power supply circuit comprises a high-side power supply circuit, the temperature dependent circuit element comprises a first temperature dependent circuit element, and the driver circuit comprises a high-side driver circuit, and the circuit further comprises a low-side driver circuit configured to be coupled to a low-side power supply circuit, wherein the low-side driver circuit is configured to deliver a modulation signal to a control node of a low-side power switch to control on / off switching of the low-side power switch, wherein the low-side driver circuit is further configured to modulate an 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 of controlling a power switch circuit, the power switch circuit comprising a power switch and a temperature dependent circuit element 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 an 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 - The method of example 60 or 61, wherein modulating the output impedance comprises switching a path of the driver circuit delivering the modulating signal from a low ohmic path to a high ohmic path, wherein the low ohmic path and the high ohmic path are alternate electrical paths through the driver circuit to the control node.

[0164] Example 63 - The method of any of examples 60-62, further comprising 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 comprising 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 within a switching period of the power switch.

[0167] Example 66 - The method of any of examples 60-65, wherein modulating the output impedance comprises switching a path of the driver circuit delivering the modulating signal from a low ohmic path to a high ohmic path, wherein the low ohmic path and the high ohmic 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 comprises disabling the power switch via a logic of the driver circuit in response to the one or more voltage measurements.

[0170] Example 69 - The method of any of examples 60-68, wherein controlling the power switch based in part on the one or more voltage measurements comprises adjusting a transition speed of the power switch in response to the voltage measurement indicative of 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 comprises adjusting the modulation signal via a controller based on the determined temperature.

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

[0174] Example 73 - A circuit arrangement 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; 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 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 in part on the one or more voltage measurements.

[0175] Example 74 - The circuit arrangement of example 73, wherein the driver circuit is configured to calculate an 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 - The circuit arrangement of example 73 or 74, wherein the driver circuit comprises: 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 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 an input impedance of the temperature dependent circuit element.

[0177] Example 76 - The circuit arrangement of 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 - The circuit arrangement of 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 - The circuit arrangement of any of examples 73-77, wherein the temperature dependent circuit element comprises a temperature dependent resistor.

[0180] Example 79 - The circuit arrangement of 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 - The circuit arrangement of 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 - The circuit arrangement of any of examples 73-80, wherein the driver circuit comprises an analog-to-digital converter for performing the one or more voltage measurements.

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

Claims

1. A circuit configured to control a power switching circuit, the power switching circuit comprising 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 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 a turn-on / off switching of the power switch, wherein 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; wherein the driver circuit comprises: 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.

2. The circuit of claim 1, wherein the driver circuit is configured to calculate an 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.

3. The circuit of claim 1: wherein 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 an input impedance of the temperature dependent circuit element.

4. The circuit of claim 3, 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 turn-on / off switching of the power switch.

5. The circuit of claim 4, 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.

6. 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 one or more voltage measurements.

7. The circuit of claim 6, wherein the circuit further comprises a control unit configured to adjust the modulation signal based on the determined temperature.

8. The circuit of claim 1, wherein the driver circuit comprises logic configured to control the power switch in response to the voltage measurements indicative of a temperature of the power switch.

9. The circuit of claim 8, wherein the logic is configured to adjust a transition speed of the power switch in response to the one or more voltage measurements.

10. The circuit of claim 8, wherein the logic is configured to disable the power switch in response to the one or more voltage measurements.

11. 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 electrically coupled to at least one node of the power switch, the method comprising: delivering, by a driver circuit, a modulation signal to a control node of the power switch to control on / off switching of the power switch; modulating, at the control node, an output impedance of the driver circuit by switching a path of the driver circuit delivering 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; 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.

12. The method of claim 11, further comprising: calculating, based on the one or more voltage measurements, an input impedance of the temperature-dependent circuit element while modulating the output impedance of the driver circuit.

13. The method of claim 11, further comprising: switching the path of the driver circuit and performing the one or more voltage measurements according to a timing sequence based on timing associated with the on / off switching of the power switch.

14. The method of claim 11, further comprising 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.

15. The method of claim 11, further comprising: controlling the power switch based at least in part on the one or more voltage measurements.

16. The method of claim 15: controlling the power switch based in part on the one or more voltage measurements includes: disabling, via logic of a driver circuit, the power switch in response to the one or more voltage measurements.

17. The method of claim 15, wherein controlling the power switch based in part on the one or more voltage measurements comprises: adjusting a transition speed of the power switch in response to the voltage measurements indicative of a temperature of the power switch.

18. The method of claim 11, further comprising: determining a temperature of the power switch based on the one or more voltage measurements.

19. The method of claim 18, controlling the power switch based in part on the one or more voltage measurements includes: adjusting, via a controller, the modulation signal based on the determined temperature.

20. A circuit apparatus, comprising: a power switch circuit comprising 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; and a driver circuit configured to: deliver a modulation signal to a control node of the power switch to control on / off switching of the power switch; modulate, at the control node, an output impedance of the driver circuit by switching a path of the driver circuit delivering 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; and perform one or more voltage measurements while modulating the output impedance of the driver circuit. a driver circuit configured to be coupled to the 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 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; wherein the driver circuit comprises: 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.

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