Temperature detection protection circuit and integrated chip

Abstract

The invention discloses a temperature detection protection circuit and an integrated chip, the temperature detection protection circuit comprises a switch control unit and a Schmidt trigger unit, the switch control unit comprises at least one triode, and the switch control unit outputs a temperature feedback voltage to the Schmidt trigger unit. The Schmidt trigger unit outputs a temperature detection signal based on the change of the temperature feedback voltage; the temperature in the integrated chip is collected and detected by utilizing the temperature characteristic of the triode, and the temperature feedback voltage output by the switch control unit is judged and noise and interference signals are removed through the hysteretic characteristic of the Schmidt trigger unit, so that the stability and reliability of the temperature detection protection circuit are improved; therefore, the temperature protection of the integrated chip is realized, and the integrated chip is prevented from being damaged due to overheating.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to a temperature detection protection circuit and an integrated chip. Background Art

[0002] With the development of industrial level and science and technology, the speed of power electronic products is getting faster and faster, and people's requirements for performance are getting higher and higher. Among them, the off-chip temperature detection module is an important part of today's monolithic integrated intelligent power driver chip. The characteristics of low power consumption and easy integration have become important design goals of the temperature detection module. However, devices such as thermocouples and thermistors are difficult to integrate and difficult to use in integrated chips. Therefore, it is of great significance to design a temperature detection circuit for integrated chips. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a temperature detection protection circuit and an integrated chip, which utilize the temperature characteristics of the transistor to detect the on-chip temperature of the integrated chip, and use a Schmitt trigger unit to judge the temperature feedback voltage output by the switch control unit, thereby improving the detection stability and realizing temperature protection of the integrated chip.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A temperature detection protection circuit includes a switch control unit, a Schmitt trigger unit, and a transistor Q1, wherein the transistor Q1 is used to detect temperature, the switch control unit is used to control the switch of the transistor Q1, the switch control unit outputs a temperature feedback voltage to the Schmitt trigger unit according to the switch condition of the transistor Q1, and the Schmitt trigger unit outputs a temperature detection signal based on the change of the temperature feedback voltage.

[0006] In the temperature detection protection circuit, the switch control unit includes a diode Z1, a diode Z2, a resistor R1, a resistor R2, a resistor R3, a field effect tube M1, a field effect tube M2, and a field effect tube M3. The emitter of the transistor Q1 is connected to the bus voltage, the base thereof is connected to the bus voltage through the resistor R3, the collector thereof is connected to the source of the field effect tube M2, the positive electrode of the diode Z1 is connected to the base of the transistor Q1, the negative electrode thereof is connected to the gate of the field effect tube M2, and the negative electrode of the diode Z2 is connected to the bus voltage. The voltage is connected, and its positive electrode is respectively connected to the drain of the field effect tube M1 and the gate of the field effect tube M2, the source of the field effect tube M1 is connected to its gate and is grounded, the drain of the field effect tube M2 is grounded through the resistor R2, and is connected to the drain of the field effect tube M3 through the resistor R1, the source of the field effect tube M3 is grounded, the gate of the field effect tube M3 is connected to the output end of the Schmitt trigger unit, and the drain of the field effect tube M2 is connected to the input end of the Schmitt trigger unit and outputs a temperature feedback voltage.

[0007] In the temperature detection protection circuit, the Schmitt trigger unit includes a transistor Q2, a transistor Q3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, and a resistor R8. The base of the transistor Q2 is connected to the drain of the field effect transistor M2, and its emitter is grounded through the resistor R7. Its collector is connected to the power supply voltage through the resistor R4 and to the base of the transistor Q3 through the resistor R8. The base of the transistor Q3 is grounded through the resistor R6, and its collector is connected to the power supply voltage through the resistor R5. Its emitter is connected to the emitter of the transistor Q2. The collector of the transistor Q3 is the output end of the Schmitt trigger unit and outputs a temperature detection signal.

[0008] In the temperature detection protection circuit, the transistor Q1 is a PNP transistor, and the transistor Q2 and the transistor Q3 are both NPN transistors.

[0009] In the temperature detection protection circuit, the diode Z1 and the diode Z2 are both voltage stabilizing diodes.

[0010] In the temperature detection protection circuit, the field effect transistor M1 and the field effect transistor M3 are both depletion-type PMOS transistors, and the field effect transistor M2 is a depletion-type NMOS transistor.

[0011] The present application also provides an integrated chip, including the temperature detection protection circuit, filter shaping circuit, dead zone interlock circuit, fault logic control circuit, drive circuit, and bootstrap circuit as described above, wherein the filter shaping circuit is connected to the drive circuit via the dead zone interlock circuit, the temperature detection protection circuit is connected to the drive circuit via the fault logic control circuit, and the bootstrap circuit is connected to the drive circuit.

[0012] The integrated chip further comprises an overload protection circuit, and the overload protection circuit is connected to the fault logic control circuit.

[0013] The integrated chip further comprises an undervoltage protection circuit, and the undervoltage protection circuit is connected to the fault logic control circuit.

[0014] The integrated chip further comprises a fault output circuit, and the fault output circuit is connected to the fault logic control circuit.

[0015] Beneficial effects:

[0016] The present invention provides a temperature detection protection circuit and an integrated chip. The temperature detection protection circuit utilizes the temperature characteristics of a transistor to collect and detect the on-chip temperature of an integrated chip, and through the hysteresis characteristics of a Schmitt trigger unit, determines the temperature feedback voltage output by a switch control unit, removes noise and interference signals, and improves the stability and reliability of the temperature detection protection circuit, thereby realizing temperature protection of the integrated chip and preventing the integrated chip from being damaged due to overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A circuit diagram of a temperature detection protection circuit provided by the present invention;

[0018] Figure 2 A topological structure diagram of the integrated chip provided by the present invention;

[0019] Figure 3 This is a signal timing diagram of the temperature detection protection circuit provided by the present invention.

[0020] Explanation of main component symbols: 1-temperature detection protection circuit, 11-switch control unit, 12-Schmitt trigger unit, 2-filter shaping circuit, 3-dead zone interlocking circuit, 4-fault logic control circuit, 5-drive circuit, 6-bootstrap circuit, 7-overload protection circuit, 8-undervoltage protection circuit, 9-fault output circuit. DETAILED DESCRIPTION

[0021] The present invention provides a temperature detection protection circuit and a high-voltage integrated chip. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] In the description of the present invention, it should be understood that the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0023] See also Figure 1 A temperature detection protection circuit includes a switch control unit 11, a Schmitt trigger unit 12, and a transistor Q1. The transistor Q1 is used to detect temperature. The switch control unit 11 is used to control the switch of the transistor Q1. The switch control unit 11 outputs a temperature feedback voltage to the Schmitt trigger unit 12 according to the switch status of the transistor Q1. The Schmitt trigger unit 12 outputs a temperature detection signal based on the change of the temperature feedback voltage.

[0024] Among them, the transistor has the following temperature characteristics. As the temperature rises, the amplification factor of the transistor will change, and its collector current will increase. In addition, the Schmitt trigger unit 12 is a Schmitt trigger. The Schmitt trigger has significant noise suppression and anti-interference capabilities based on its hysteresis characteristics. Preferably, the transistor Q1 can be set close to the main heat-generating module in the integrated chip to improve the accuracy of temperature detection.

[0025] See also Figure 3 The temperature detection protection circuit of the present invention utilizes the temperature characteristics of the transistor to collect and detect the temperature inside the integrated chip, and through the hysteresis characteristics of the Schmitt trigger unit 12, the temperature feedback voltage U1 output by the switch control unit 11 is judged. When the temperature feedback voltage U1 is higher than the positive threshold voltage UT+ of the Schmitt trigger unit 12 or lower than its negative threshold voltage UT-, the output temperature detection signal OTP jumps accordingly. Therefore, the Schmitt trigger unit 12 can effectively remove noise and interference signals, improve the stability and reliability of the temperature detection protection circuit, thereby realizing temperature protection of the integrated chip and preventing the integrated chip from being damaged due to overheating.

[0026] See also Figure 1Specifically, the switch control unit 11 includes a diode Z1, a diode Z2, a resistor R1, a resistor R2, a resistor R3, a field effect transistor M1, a field effect transistor M2, and a field effect transistor M3. The emitter of the transistor Q1 is connected to the bus voltage VB, the base thereof is connected to the bus voltage VB through the resistor R3, the collector thereof is connected to the source of the field effect transistor M2, the anode of the diode Z1 is connected to the base of the transistor Q1, the cathode thereof is connected to the gate of the field effect transistor M2, and the cathode of the diode Z2 is connected to the bus voltage VB. Its positive electrode is respectively connected to the drain of the field effect tube M1 and the gate of the field effect tube M2, the source of the field effect tube M1 is connected to its gate and is grounded GND, the drain of the field effect tube M2 is grounded GND through the resistor R2, and is connected to the drain of the field effect tube M3 through the resistor R1, the source of the field effect tube M3 is grounded GND, the gate of the field effect tube M3 is connected to the output end of the Schmitt trigger unit 12, and the drain of the field effect tube M2 is connected to the input end of the Schmitt trigger unit and outputs a temperature feedback voltage.

[0027] Preferably, the diode Z1 and the diode Z2 are both voltage-stabilizing diodes, and the diode Z2 can ensure the voltage between the gate and the source of the field effect transistor M2.

[0028] The switch control unit 11 is based on the aforementioned circuit design. When the temperature in the chip continues to rise, the collector current of the transistor Q1 increases, that is, the current flowing into the source of the field effect M2 increases, then the drain voltage output by the field effect M2 increases, that is, the temperature feedback voltage U1 increases, thereby reaching the positive threshold voltage UT+ of the Schmitt trigger unit 12, triggering the temperature detection signal OTP to jump. On the contrary, the temperature feedback voltage U1 decreases to below the positive threshold voltage UT- of the Schmitt trigger unit 12, triggering the temperature detection signal OTP to jump.

[0029] In addition, the field effect tube M1 is equivalent to a variable resistor based on its wiring method. In practical applications, those skilled in the art can adjust the size parameters of the resistor R3 and the field effect tube M1 so that below a certain temperature, the voltage drop on the resistor R3 causes the transistor Q1 to be cut off or weakly turned on, and then the temperature feedback voltage U1 output by the switch control unit 11 is not enough to cause the temperature detection signal OTP output by the Schmitt trigger unit 12 to jump. On the contrary, when the temperature is above a certain temperature, the transistor Q1 is turned on, and the temperature detection signal OTP output by the Schmitt trigger unit 12 jumps. Preferably, the aforementioned temperature threshold can be controlled between 140 degrees Celsius and 160 degrees Celsius by adjusting the size parameters of the resistor R3 and the field effect tube M1.

[0030] See also Figure 1 Specifically, the Schmitt trigger unit 12 includes a transistor Q2, a transistor Q3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, and a resistor R8. The base of the transistor Q2 is connected to the drain of the field effect transistor M2, and its emitter is grounded GND through the resistor R7. The collector is connected to the power supply voltage VCC through the resistor R4 and to the base of the transistor Q3 through the resistor R8. The base of the transistor Q3 is grounded GND through the resistor R6, and its collector is connected to the power supply voltage VCC through the resistor R5. The emitter is connected to the emitter of the transistor Q2. The collector of the transistor Q3 is the output end of the Schmitt trigger unit 12 and outputs a temperature detection signal.

[0031] Based on the circuit design of the Schmitt trigger unit 12, when the temperature feedback voltage U1 is lower than the forward threshold voltage UT-, the transistor Q2 is turned off due to the lack of base bias current, and the power supply voltage VCC provides the base bias current for the transistor Q3 through the resistor R4 and the resistor R8, and the transistor Q3 is turned on. At the same time, the voltage drop generated by the resistor R7 makes the circuit stable in the state where the transistor Q3 is turned on and the transistor Q2 is turned off, and the temperature detection signal OTP is flipped from a low level and maintained at a high level. On the contrary, when the temperature feedback voltage U1 is higher than the forward threshold voltage UT+, the transistor Q2 is turned on, so that the transistor Q3 is turned off. At the same time, the voltage drop generated by the resistor R7 makes the circuit stable in the state where the transistor Q2 is turned on and the transistor Q3 is turned off, and the temperature detection signal OTP is flipped from a high level and maintained at a low level.

[0032] Preferably, the transistor Q1 is a PNP transistor, and the transistor Q2 and the transistor Q3 are both NPN transistors.

[0033] Preferably, the field effect transistor M1 and the field effect transistor M3 are both depletion-type PMOS transistors, and the field effect transistor M2 is a depletion-type NMOS transistor.

[0034] See also Figure 2The present application also provides an integrated chip, including the temperature detection protection circuit 1, the filter shaping circuit 2, the dead zone interlock circuit 3, the fault logic control circuit 4, the drive circuit 5, and the bootstrap circuit 6 as described above, wherein the filter shaping circuit 2 is connected to the drive circuit 5 through the dead zone interlock circuit 3, the temperature detection protection circuit 1 is connected to the drive circuit 5 through the fault logic control circuit 4, and the bootstrap circuit 6 is connected to the drive circuit 5. The filter shaping circuit 2 is used to filter and shape the input high-voltage signal HIN and low-voltage signal LIN, the dead zone interlock circuit 3 is used to protect the circuit and its system, the bootstrap circuit 6 is used to boost the drive circuit 5, and the fault logic control circuit 4 is used to output fault signals of different fault conditions to control or regulate the working state of the drive circuit 5.

[0035] For those skilled in the art, the filtering and shaping circuit 2 can use existing technologies such as RC filters and Schmitt triggers composed of resistors and capacitors to achieve the effect of filtering and shaping. The dead zone interlocking circuit 3 can use existing technologies such as RC delay circuits and Schmitt triggers to introduce dead time to the input signal, and the interlocking between signals can be realized by logic circuits such as AND gates, NOT gates, and OR gates, among which a CMOS inverter composed of PMOS tubes and NMOS tubes can be used as an example of NOT gates. The bootstrap circuit 6, that is, the boost circuit, can use energy storage elements such as capacitors and inductors, cooperate with elements such as triodes and MOS tubes to realize the switching function, control the charging and discharging of the energy storage elements, and boost the signal output by the driving circuit 5. The fault logic control circuit 4 can be composed of switch control elements such as triodes and MOS tubes, and is realized by using existing logic circuits such as AND gates, NOT gates, and OR gates, such as Schmitt triggers, CMOS inverters, etc., when a fault signal occurs, that is, the fault signal is "1" or "0" or reaches a certain threshold voltage trigger.

[0036] Thermocouples, thermistors and other devices in the prior art are difficult to integrate and difficult to use in integrated chips. Existing integrated chips mainly detect the chip temperature through an off-chip temperature detection circuit to control the temperature chip operation. If the off-chip temperature detection circuit fails, the chip will be damaged by overheating. The integrated chip provided by the present application integrates the temperature detection protection circuit 1 in the chip. The temperature detection protection circuit 1 is designed with easy-to-integrate devices such as transistors and field effect transistors. The temperature characteristics of the transistor are used to collect and detect the on-chip temperature of the integrated chip, and the hysteresis characteristics of the Schmitt trigger unit 12 are used to judge the temperature feedback voltage U1 output by the switch control unit 11, remove noise and interference signals, and improve the stability and reliability of the temperature detection protection circuit, thereby realizing temperature protection of the integrated chip and avoiding damage to the integrated chip due to overheating.

[0037] Furthermore, the integrated chip also includes an overload protection circuit 7, which is connected to the fault logic control circuit 4; the overload protection circuit 7 can prevent the integrated chip from burning or failing due to overload. Specifically, the overload protection circuit 7 can be implemented using existing components such as voltage regulator diodes and thyristors, or using a potential clamping circuit in the prior art to limit the voltage.

[0038] Furthermore, the integrated chip further includes an undervoltage protection circuit 8, which is connected to the fault logic control circuit 4 to prevent the high-voltage integrated chip from failing due to undervoltage. Specifically, the undervoltage protection circuit 8 can be implemented by using a voltage comparator in the prior art, and a signal is fed back to the fault logic control circuit 4 when the collected voltage is lower than the threshold voltage. Furthermore, a hysteresis comparator, such as a Schmitt trigger, can be used to reduce signal interference and noise.

[0039] Furthermore, the integrated chip further includes a fault output circuit 9, which is connected to the fault logic control circuit 4; the fault output circuit 9 is used to receive a fault signal output by an off-chip module to prevent the normal operation of the chip from being affected by a fault generated outside the chip. Specifically, the fault output circuit 9 can be implemented by a single MOS tube, triode or other switch control element. When a fault signal is input, the switch control element is turned on or off and feeds back a signal to the fault logic control circuit 4.

[0040] In summary, the present application provides a temperature detection protection circuit and an integrated chip. The temperature detection protection circuit uses the temperature characteristics of the transistor to collect and detect the temperature inside the integrated chip, and through the hysteresis characteristics of the Schmitt trigger unit 12, the temperature feedback voltage U1 output by the switch control unit 11 is judged. When the temperature feedback voltage U1 is higher than the positive threshold voltage UT+ of the Schmitt trigger unit 12 or lower than its negative threshold voltage UT-, the output temperature detection signal OTP jumps accordingly. Therefore, the Schmitt trigger unit 12 can effectively remove noise and interference signals, improve the stability and reliability of the temperature detection protection circuit, thereby realizing temperature protection of the integrated chip and preventing the integrated chip from being damaged due to overheating.

[0041] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A temperature detection protection circuit, characterized in that: It includes a switch control unit, a Schmitt trigger unit, and a transistor Q1. The transistor Q1 is used to detect temperature. The switch control unit is used to control the switch of the transistor Q1. The switch control unit outputs a temperature feedback voltage to the Schmitt trigger unit according to the switch status of the transistor Q1. The Schmitt trigger unit outputs a temperature detection signal based on the change of the temperature feedback voltage.

2. The temperature detection protection circuit according to claim 1, characterized in that: The switch control unit includes a diode Z1, a diode Z2, a resistor R1, a resistor R2, a resistor R3, a field effect transistor M1, a field effect transistor M2, and a field effect transistor M3. The emitter of the transistor Q1 is connected to the bus voltage, the base of the transistor Q1 is connected to the bus voltage through the resistor R3, and the collector of the transistor Q1 is connected to the source of the field effect transistor M2. The anode of the diode Z1 is connected to the base of the transistor Q1, and the cathode of the diode Z1 is connected to the gate of the field effect transistor M2. The cathode of the diode Z2 is connected to the bus voltage. The positive electrode is respectively connected to the drain of the field effect tube M1 and the gate of the field effect tube M2, the source of the field effect tube M1 is connected to its gate and is grounded, the drain of the field effect tube M2 is grounded through the resistor R2, and is connected to the drain of the field effect tube M3 through the resistor R1, the source of the field effect tube M3 is grounded, the gate of the field effect tube M3 is connected to the output end of the Schmitt trigger unit, and the drain of the field effect tube M2 is connected to the input end of the Schmitt trigger unit and outputs a temperature feedback voltage.

3. The temperature detection protection circuit according to claim 2, characterized in that: The Schmitt trigger unit includes a transistor Q2, a transistor Q3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, and a resistor R8. The base of the transistor Q2 is connected to the drain of the field effect transistor M2, and its emitter is grounded through the resistor R7. The collector is connected to the power supply voltage through the resistor R4 and to the base of the transistor Q3 through the resistor R8. The base of the transistor Q3 is grounded through the resistor R6, and its collector is connected to the power supply voltage through the resistor R5. The emitter is connected to the emitter of the transistor Q2. The collector of the transistor Q3 is the output end of the Schmitt trigger unit and outputs a temperature detection signal.

4. The temperature detection protection circuit according to claim 3, characterized in that: The transistor Q1 is a PNP transistor, and the transistor Q2 and the transistor Q3 are both NPN transistors.

5. The temperature detection protection circuit according to claim 3, characterized in that: The diode Z1 and the diode Z2 are both voltage stabilizing diodes.

6. The temperature detection protection circuit according to claim 3, characterized in that: The field effect transistor M1 and the field effect transistor M3 are both depletion-type PMOS transistors, and the field effect transistor M2 is a depletion-type NMOS transistor.

7. An integrated chip, characterized in that: It includes a temperature detection protection circuit, a filter shaping circuit, a dead zone interlock circuit, a fault logic control circuit, a drive circuit, and a bootstrap circuit as described in any one of claims 1 to 6, wherein the filter shaping circuit is connected to the drive circuit via the dead zone interlock circuit, the temperature detection protection circuit is connected to the drive circuit via the fault logic control circuit, and the bootstrap circuit is connected to the drive circuit.

8. The integrated chip according to claim 7, characterized in that: It also includes an overload protection circuit, which is connected to the fault logic control circuit.

9. The integrated chip according to claim 7, characterized in that: It also includes an undervoltage protection circuit, which is connected to the fault logic control circuit.

10. The integrated chip according to claim 7, characterized in that: It also includes a fault output circuit, which is connected to the fault logic control circuit.

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