Power device and temperature detection method thereof

Abstract

The present application provides a power device and a temperature detection method thereof. The power device includes a power switch and a detection unit. The power switch is electrically connected between a first detection node and a second detection node. The detection nodes are electrically connected between a plurality of power source nodes. The detection nodes are substantially two terminals of the power switch. When the power switch is turned on, the power switch is used to transmit the current flowing through the power source nodes. The detection unit is electrically connected to the first detection node and the second detection node to detect the voltage across the two terminals of the power switch to generate a detection voltage.

Description

Technical Field

[0001] This disclosure relates to a power device and a method for detecting the temperature of the same, and more particularly to a technique for detecting the trans-voltage of the power device to determine its temperature. Background Technology

[0002] A power module is a structure that encapsulates power semiconductor elements and typically serves as the core of power conversion and circuit control in electronic devices. Applications of power modules include frequency conversion, rectification, voltage transformation, power amplification, and power control, while also offering energy-saving benefits. Therefore, they are widely used in mobile communications, consumer electronics, energy devices, and many other fields. Summary of the Invention

[0003] One embodiment of this disclosure is a power device comprising a power switch and a detection unit. The power switch is electrically connected between a first detection node and a second detection node, which are electrically connected between multiple power supply nodes. These detection nodes are essentially the two ends of the power switch. When the power switch is turned on, it transmits current flowing through the power supply nodes. The detection unit is electrically connected to the first and second detection nodes and is used to detect the voltage across the power switch to generate a detection voltage.

[0004] Another embodiment of this disclosure is a method for detecting the temperature of a power device, comprising the following steps: turning on a power switch to transmit current flowing through a plurality of power supply nodes, wherein the power switch is electrically connected between a first detection node and a second detection node, the first detection node and the second detection node are electrically connected between the power supply nodes, and the first detection node and the second detection node are essentially the two ends of the power switch; detecting the voltage across the two ends of the power switch through a detection unit to generate a detection voltage, wherein the detection unit is electrically connected to the detection nodes; and converting the detection voltage into a detection temperature value through a conversion unit.

[0005] Another embodiment of this disclosure is a power device comprising a plurality of power switches and at least one detection unit. Any one of the power switches is electrically connected between a plurality of detection nodes, and the detection nodes are electrically connected between a plurality of power supply nodes. The detection nodes are essentially the two ends of the power switches. When any of the power switches is turned on, the power switches transmit current flowing through the power supply nodes. The detection unit is electrically connected to the detection nodes to detect the voltage across the two ends of the power switches, thereby generating a detection voltage.

[0006] Since the detection unit is directly connected to both ends of the power switch and generates a detection voltage based on the cross voltage when the power switch is turned on, it can ensure that the detection voltage is not affected by the conductor impedance in the power device, so that the detection voltage can accurately reflect the current temperature of the power switch. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of a power device according to some embodiments of the present disclosure;

[0008] Figure 2 This is a schematic diagram of a detection unit according to some embodiments of the present disclosure;

[0009] Figure 3 This is a flowchart of a temperature detection method according to some embodiments of the present disclosure;

[0010] Figures 4A to 4D This is a schematic diagram of a power device according to some embodiments of the present disclosure;

[0011] Figures 5A-5C This is a schematic diagram of a power device according to some embodiments of the present disclosure.

[0012] Explanation of reference numerals in the attached figures

[0013] 100: Power device

[0014] 200: Detection Unit

[0015] 210: Withstand voltage circuit

[0016] 211: Withstand Voltage Switch

[0017] 220: Clamping circuit

[0018] 230: Output Circuit

[0019] 231: Voltage divider circuit

[0020] 232: Filtering circuit

[0021] 300: Conversion Unit

[0022] 310: Processor

[0023] 320: Memory

[0024] 321: Conversion Table

[0025] 410-440: Power devices

[0026] 500: Power Device

[0027] 511: First power switch

[0028] 512: Second power switch

[0029] 513: Third Power Switch

[0030] 520: Selection Circuit

[0031] 530: Conversion Unit

[0032] MS: Power Switch

[0033] Na: First detection node

[0034] Nb: Second detection node

[0035] N1-N2: Power supply nodes

[0036] D1: Zener diode

[0037] D2: Zener diode

[0038] Rpd: Stray resistance

[0039] Lpd: Stray inductance

[0040] Rps: Stray resistance

[0041] Lps: Stray inductance

[0042] P: Circuit board

[0043] De: Chip

[0044] Dg: Driver chip

[0045] Dp: Circuit board

[0046] MS1: First power switch

[0047] MS2: Second power switch

[0048] MS3: Third Power Switch Detailed Implementation

[0049] Several embodiments of the present invention will be disclosed below with reference to the accompanying drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and elements will be shown in the drawings in a simple schematic manner.

[0050] In this document, when an element is referred to as a “connection” or “coupled,” it may mean an “electrical connection” or “electrical coupling.” “Connection” or “coupled” can also be used to indicate the operation or interaction between two or more elements. Furthermore, although terms such as “first,” “second,” etc., are used herein to describe different elements, these terms are merely used to distinguish elements or operations described using the same technical terminology. Unless the context clearly indicates otherwise, these terms do not specifically refer to or imply any order or sequence, nor are they intended to limit the invention.

[0051] Figure 1 This is a schematic diagram of a power device 100 according to a partial embodiment of the present disclosure. The power device 100 includes at least a power switch MS (main switch). The power switch MS can be implemented using power semiconductor elements and can be electrically connected to an external device to provide functions such as frequency conversion, rectification, voltage transformation, power amplification, or power control. Figure 1 In the circuit shown, the power switch MS is a metal-oxide-semiconductor field-effect transistor (MOSFET), but this disclosure is not limited thereto. In other embodiments, the power switch MS can also be implemented by an insulated gate bipolar transistor (IGBT).

[0052] In one embodiment, the power switch MS is electrically connected to a driver die. To ensure proper operation of the power switch MS, a power-type thermistor (NTC) or diode can be incorporated within the power device 100 to determine the temperature of the power switch MS based on voltage changes. However, both NTC and diode-based temperature detection methods are not ideal.

[0053] Please see Figure 1 As shown, this disclosure describes a method where the detection unit 200 directly detects the voltage across the power switch MS to calculate the current temperature of the power switch MS based on the voltage-temperature relationship. In this embodiment, the power switch MS is electrically connected between the first detection node Na and the second detection node Nb, and the first detection node Na and the second detection node Nb are located between two power supply nodes N1 and N2.

[0054] like Figure 1As shown, at least one stray resistance Rpd, Rps and at least one stray inductance Lpd, Lps exist between power nodes N1, N2 and detection nodes Na, Nb. The stray resistances Rpd, Rps and the stray inductances Lpd, Lps are connected in series between power nodes N1, N2 and detection nodes Na, Nb, and are formed by conductors in the power device 100. In other words, detection nodes Na, Nb are essentially the two ends of the power switch MS, and there is no extra conductor impedance between detection nodes Na, Nb and the power switch MS (or the impedance is too small to be ignored). When the power switch MS is turned on, it transmits current, allowing the current to flow through the power nodes N1, N2.

[0055] The detection unit 200 is directly connected to the first detection node Na and the second detection node Nb to detect the voltage across the power switch MS and generate a detection voltage based on the detection result. The current temperature of the power switch MS can be determined based on the relative relationship between its voltage and temperature. Furthermore, since the detection unit 200 is directly connected in parallel across the power switch MS (i.e., the first detection node Na and the second detection node Nb), rather than connected to power supply nodes N1 and N2, the detection voltage obtained by the detection unit 200 directly reflects the voltage across the power switch MS without being affected by impedance or parasitic inductance on the conductors.

[0056] like Figure 1 As shown, in some embodiments, the power device 100 further includes a conversion unit 300. The conversion unit 300 is electrically connected to the detection unit 200 and is used to receive the detection voltage value transmitted from the detection unit 200. The conversion unit 300 includes a processor 310 and a memory 320, and the memory 320 pre-stores a conversion table 321. The conversion table 321 records the temperature values ​​of the power switch MS under various voltage conditions. The processor 310 can look up the conversion table 321 based on the detection voltage value to find the detection temperature value corresponding to the detection voltage.

[0057] On the other hand, the power switch MS is in a conducting or turning-off state depending on the operation of the external device (or driver chip). The voltage across the power switch MS differs significantly when it is conducting or turning off. Specifically, when the power switch MS is off, the voltage across its terminals is much greater than when it is conducting. If the detection unit 200 receives both extremely large and extremely small voltages during the detection process, the extremely small voltage (i.e., the voltage across the power switch MS when it is conducting) will be ignored or miscalculated when the conversion unit 300 calculates the detected temperature value, leading to inaccurate results. Therefore, in some embodiments, the detection unit 200 only receives the voltage across the power switch MS when it is "conducting" and obtains the detected voltage value based on this voltage. Conversely, the detected temperature value obtained by the conversion unit 300 also corresponds to the voltage across the power switch MS when it is "conducting".

[0058] Figure 2 This is a schematic diagram of a detection unit 200 according to a partial embodiment of the present disclosure. In some embodiments, the detection unit 200 includes a withstand voltage circuit 210, a clamping circuit 220, and an output circuit 230. The withstand voltage circuit 210 is electrically connected to the first detection node Na and includes a withstand voltage switch 211. When the power switch MS is turned off, the voltage across the power switch MS will cause the withstand voltage switch 211 to turn off (i.e., form an open circuit), but the voltage across the power switch MS is less than the rated voltage of the withstand voltage switch 211 to ensure that the withstand voltage switch 211 is not damaged.

[0059] Clamping circuit 220 is electrically connected between withstand voltage circuit 210 and second detection node Nb, and withstand voltage switch 211 is electrically connected between first detection node Na and clamping circuit 220. In other words, the first terminal (drain) of withstand voltage switch 211 is connected to the first detection point Na, and the second terminal (source) of withstand voltage switch 211 is connected to clamping circuit 220. When power switch MS is turned on and withstand voltage switch 211 is turned on accordingly, clamping circuit 220 is used to clamp the output of withstand voltage circuit 210 (e.g., the source voltage of withstand voltage switch 211) to form clamping voltage V1.

[0060] In some embodiments, the clamping circuit 220 includes at least one Zener diode D1, such that the clamping voltage V1 connected to one end of the withstand voltage circuit 210 is less than the voltage across the two ends when the power switch MS is turned off. Therefore, the clamping circuit 220 further ensures that the clamping voltage V1 remains within a certain voltage range to avoid damage to the detection unit 200. In other embodiments, the clamping circuit 220 includes multiple Zener diodes D1 and D2, wherein the node between Zener diodes D1 and D2 is connected to the control terminal (gate) of the withstand voltage switch 211, and Zener diode D2 is connected to the second terminal (source) of the withstand voltage switch 211.

[0061] Output circuit 230 is electrically connected to the second terminal of clamping circuit 220 and withstand voltage switch 211 to receive clamping voltage V1 and generate detection voltage V2 based on clamping voltage V1. In some embodiments, output circuit 230 also includes voltage divider circuit 231. Voltage divider circuit 231 receives clamping voltage V1 and divides clamping voltage V1 through multiple resistors of different impedances to convert clamping voltage V1 into detection voltage V2. Detection voltage V2 will correspond to the operating voltage range of processor 310 of conversion unit 300 (e.g., reducing clamping voltage V1 to a certain proportion).

[0062] In other embodiments, the output circuit 230 further includes a filter circuit 232 composed of resistors and capacitors. The output circuit 230 first filters out high-frequency noise in the clamping voltage V1 through the filter circuit, and then transmits the filtered voltage to the voltage divider circuit 231 to output the detection voltage V2.

[0063] Figure 3 This is a flowchart of a temperature detection method according to a partial embodiment of the present disclosure. In step S301, the power switch MS is turned on to transmit current through power nodes N1 and N2. The power switch MS is connected to an external device or chip and is controlled to be in an on or off state as the external device or chip operates.

[0064] In step S302, it is determined whether the power switch MS is on. If the power switch MS is off, then in step S303, the voltage across the power switch MS will cause the withstand voltage switch 211 in the withstand voltage circuit 210 to turn off, thus creating an open circuit in the withstand voltage circuit 210.

[0065] If the power switch MS is turned on, in step S304, the voltage across the power switch MS will turn on the withstand voltage switch 211 in the withstand voltage circuit 210, and the clamping circuit 220 will clamp the output voltage of the withstand voltage circuit 210 to generate a clamping voltage V1.

[0066] In step S305, the output circuit 230 performs voltage division based on the clamping voltage V1 to detect the voltage value V2. The detected voltage value V corresponds to the voltage across the power switch MS and falls within the operating voltage range of the processor in the conversion unit 300. In step S306, the conversion unit 300 receives the detected voltage. The conversion unit 300 has a pre-stored conversion table 321 showing the correspondence between the detected voltage V2 and temperature. The processor 310 looks up the conversion table 321 to find the temperature value corresponding to the detected voltage, which is then used as the detected temperature value for the current temperature of the corresponding power switch MS.

[0067] Figure 1In the illustrated embodiment, the power device 100 includes a power switch MS, but in other embodiments, the power device 100 may encapsulate multiple power switches MS. Figures 4A to 4D These are different embodiments of power devices 410 to 440. Figures 4A to 4D In, with Figure 1 Similar elements related to the embodiments are denoted by the same reference numerals for ease of understanding, and the specific principles of the similar elements have been described in detail in the preceding paragraphs. Figures 4A to 4D The components that work together in a coordinated manner will not be elaborated upon here.

[0068] Please see Figure 4A As shown, the power device 410 includes multiple power switches MS and detection units 200, each power switch MS being electrically connected between two detection nodes (e.g., Figure 1 The first detection node Na and the second detection node Nb are shown, and each detection node is electrically connected between two power supply nodes (e.g., ...). Figure 1 The power nodes N1 and N2 are shown. In other words, each power switch MS has a detection node at both ends. When the power switch MS is turned on, it transmits current flowing between the power nodes to perform its function (e.g., controlling or adjusting the current output to external devices or chips). The detection unit 200 is electrically connected to these power switches MS to detect the voltage across each power switch MS and generate a corresponding detection voltage.

[0069] like Figure 4A As shown, the power switches MS are uniformly packaged on a separate circuit board P, while the detection unit 200 is located on another chip De. The circuit board P and the chip De are electrically connected, so that the detection unit 200 can be electrically connected to these power switches MS through the chip De and detect the voltage across the two ends of the power switches MS.

[0070] like Figure 4B As shown, in other embodiments, the detection unit 200 and the power switches MS are all disposed on a circuit board P and electrically connected to each other through the circuit board P. Each detection unit 200 corresponds to a certain number of power switches MS to detect the voltage across its terminals. The circuit details of the connection between the detection unit 200 and the multiple power switches MS will be described in a later paragraph.

[0071] like Figure 4C As shown, in some embodiments, the power switch MS is uniformly packaged on a separate circuit board P, the detection unit 200 and the driver chip Dg (Gate Driver IC) are packaged as one unit, and the driver chip Dg is electrically connected to the circuit board P.

[0072] like Figure 4DAs shown, in some embodiments, the power switch MS is uniformly packaged on a separate circuit board P, while the detection unit 200 and the conversion unit 300 are packaged on the setting driver chip ( Figure 4D (Not shown in the image) On another circuit board Dp. Circuit board Dp is electrically connected to these power switches MS via circuit board P.

[0073] Figure 5A This is a schematic diagram of a power device 500 according to other embodiments of the present disclosure. The power device 500 includes multiple power switches MS1-MS3, multiple detection units 511-513, a selection circuit 520, and a conversion unit 530. Each detection unit 511-513 corresponds to one power switch MS1-MS3 to detect the voltage across the corresponding power switch MS1-MS3 and obtain the corresponding detection voltage. For example, the first detection unit 511 detects the first detection voltage of the first power switch MS1, the second detection unit 512 detects the second detection voltage of the second power switch MS2, and the third detection unit 513 detects the third detection voltage of the third power switch MS3. The conversion unit 300 is selectively electrically connected to the detection units 511-513 via the selection circuit 520 (e.g., a dataselector) to receive the detection voltages.

[0074] Figure 5B and Figure 5C This is a schematic diagram of selection circuit 520 according to a partial embodiment of this disclosure. Please refer to... Figure 5B As shown, in one embodiment, the selection circuit 520 includes multiple controllable switches T1 to T3, each controllable switch T1 to T3 corresponding to one of the detection units 511 to 513, and simultaneously connected to the conversion unit 530. The power device 500 turns on the control terminal of any of the controllable switches T1 to T3, so that the conversion unit 500 receives only one detection voltage at a time. Accordingly, the power device 500 can periodically or sequentially measure the voltage across each power switch MS1 to MS3 and determine the corresponding temperature value.

[0075] like Figure 5CAs shown, in other embodiments, the selection circuit 520 includes multiple unidirectional switches Ta to Tc (e.g., diodes). These unidirectional switches Ta to Tc are electrically connected to detection units 511 to 513 to receive the detection voltages output by these units. Each unidirectional switch Ta to Tc corresponds to one of the detection units 511 to 513 and is also connected to the conversion unit 530. Since the unidirectional switches Ta to Tc only conduct in one direction, when all detection units 511 to 513 output their corresponding detection voltage values, the conversion unit 300 will only receive the highest detection voltage. In other words, the conversion unit 300 will look up the corresponding temperature value using a conversion table based on the highest current detection voltage.

[0076] The elements, method steps, or technical features in the foregoing embodiments can be combined with each other, and are not limited to the order of textual description or the order of presentation of the drawings in this disclosure.

[0077] Although the present disclosure has been described above with reference to embodiments, it is not intended to limit the present disclosure. Any person skilled in the art may make various modifications and refinements without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims.

Claims

1. A power device, comprising: A power switch is electrically connected between a first detection node and a second detection node, and multiple detection nodes are electrically connected between multiple power supply nodes. The multiple detection nodes are essentially the two ends of the power switch. When the power switch is turned on, the power switch is used to transmit the current flowing through the multiple power supply nodes. as well as The detection unit is electrically connected to the first detection node and the second detection node to detect the voltage across the power switch and generate a detection voltage. At least one stray resistor and at least one stray inductor are connected in series between one of the plurality of power supply nodes and one of the plurality of detection nodes; The detection unit includes: A withstand voltage circuit is electrically connected to the first detection node, wherein the withstand voltage circuit is used to form an open circuit based on the cross voltage across the power switch when the power switch is turned off; A clamping circuit is electrically connected to the withstand voltage circuit and is used to clamp the output of the withstand voltage circuit to generate a clamping voltage. as well as An output circuit, electrically connected to the clamping circuit, is used to receive the clamping voltage output by the clamping circuit and generate the detection voltage based on the clamping voltage. A conversion unit, electrically connected to the detection unit, is used to receive the detection voltage. The conversion unit includes a processor, which looks up a conversion table based on the detection voltage to obtain a temperature value corresponding to the detection voltage, as the detection temperature value.

2. The power device according to claim 1, wherein the clamping circuit is electrically connected between the withstand voltage circuit and the second detection node, and the withstand voltage circuit comprises: A withstand voltage switch, wherein a first terminal of the withstand voltage switch is electrically connected to the first detection node, and a second terminal of the withstand voltage switch is electrically connected to the clamping circuit, wherein when the power switch is turned off, the voltage across the power switch is less than the rated voltage of the withstand voltage switch.

3. The power device of claim 1, wherein the clamping circuit comprises at least a Zener diode, and the clamping voltage of the clamping circuit is less than the voltage across the power switch when the power switch is turned off.

4. The power device according to claim 1, wherein the detection unit comprises: A withstand voltage circuit is electrically connected to the first detection node, wherein the withstand voltage circuit is used to form an open circuit based on the cross voltage across the power switch when the power switch is turned off; A clamping circuit is electrically connected to the withstand voltage circuit and is used to clamp the output of the withstand voltage circuit to generate a clamping voltage. as well as The output circuit is electrically connected to the clamping circuit to receive the clamping voltage output by the clamping circuit and generate the detection voltage based on the clamping voltage.

5. The power device according to claim 4, wherein the clamping circuit is electrically connected between the withstand voltage circuit and the second detection node, and the withstand voltage circuit comprises: A withstand voltage switch, wherein a first terminal of the withstand voltage switch is electrically connected to the first detection node, and a second terminal of the withstand voltage switch is electrically connected to the clamping circuit, wherein when the power switch is turned off, the voltage across the power switch is less than the rated voltage of the withstand voltage switch; and The clamping circuit described therein includes at least: A Zener diode, wherein the clamping voltage of the clamping circuit is less than the voltage across the power switch when the power switch is turned off.

6. A temperature detection method applicable to a power device as described in any one of claims 1-5, comprising: A power switch is turned on to transmit current flowing through multiple power nodes, wherein the power switch is electrically connected between a first detection node and a second detection node, the first detection node and the second detection node are electrically connected between the multiple power nodes, and the first detection node and the second detection node are essentially the two ends of the power switch. The detection unit detects the voltage across the two ends of the power switch to generate a detection voltage, wherein the detection unit is electrically connected to the plurality of detection nodes; as well as The detection voltage is converted into a detection temperature value by a conversion unit.

7. The temperature detection method according to claim 6, further comprising: Turn off the power switch to create an open circuit in the withstand voltage circuit within the detection unit based on the voltage across the power switch when it is turned off.

8. The temperature detection method according to claim 7, wherein the method for generating the detection voltage value comprises: The output of the withstand voltage circuit is clamped by a clamping circuit to generate a clamping voltage; and The clamping voltage is converted into a detection voltage corresponding to the processor's operating voltage range by a voltage divider circuit.

9. The temperature detection method according to claim 6, wherein the method of converting the detection voltage into the detection temperature value comprises: According to the conversion table, find the temperature value corresponding to the detection voltage, and use it as the detection temperature value.

10. A power device comprising: Multiple power switches, any one of which is electrically connected between multiple detection nodes, and the multiple detection nodes are electrically connected between multiple power supply nodes, wherein the multiple detection nodes are essentially the two ends of the multiple power switches, and when any one of the power switches is turned on, the power switch is used to transmit current flowing through the multiple power supply nodes; as well as At least one detection unit is electrically connected to the plurality of detection nodes to detect the voltage across the two ends of the plurality of power switches in order to generate a detection voltage; The plurality of power switches include a first power switch and a second power switch, and the at least one detection unit includes a first detection unit and a second detection unit. The first detection unit is used to detect a first detection voltage of the first power switch, and the second detection unit is used to detect a second detection voltage of the second power switch. The conversion unit is electrically connected to the first detection unit and the second detection unit through a plurality of unidirectional switches to receive the first detection voltage or the second detection voltage. The detection unit includes: A withstand voltage circuit is electrically connected to the first detection node, wherein the withstand voltage circuit is used to form an open circuit based on the cross voltage across the power switch when the power switch is turned off; A clamping circuit is electrically connected to the withstand voltage circuit and is used to clamp the output of the withstand voltage circuit to generate a clamping voltage. as well as An output circuit, electrically connected to the clamping circuit, is used to receive the clamping voltage output by the clamping circuit and generate the detection voltage based on the clamping voltage. A conversion unit, electrically connected to the at least one detection unit, is used to look up a conversion table based on the detection voltage to output a detection temperature value corresponding to the detection voltage.

11. The power device according to claim 10, wherein the detection unit is disposed on a chip, and the chip is electrically connected to the plurality of power switches.

12. The power device according to claim 10, wherein the detection unit and the plurality of power switches are all disposed on a circuit board.

13. The power device according to claim 10, wherein the detection unit is packaged as an integral unit with the driver chip.

14. The power device according to claim 10, wherein the detection unit and the conversion unit are both disposed on a circuit board, and the circuit board is electrically connected to the plurality of power switches.

15. The power device of claim 10, wherein the plurality of power switches includes a first power switch and a second power switch, the at least one detection unit includes a first detection unit and a second detection unit, the first detection unit is configured to detect a first detection voltage of the first power switch, the second detection unit is configured to detect a second detection voltage of the second power switch, and the conversion unit selectively receives the first detection voltage or the second detection voltage.

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