Temperature protection circuit based on hysteresis comparator and intelligent power module equipped with it

Abstract

This invention relates to the field of intelligent power module technology, and particularly to a temperature protection circuit based on a hysteresis comparator and an intelligent power module incorporating the same. The circuit includes: a reference current source module connected to a temperature detection circuit, which is connected to the positive input terminal of the hysteresis comparator via a resistor R1; one end of resistor R1 and the positive input terminal of the hysteresis comparator are connected to one end of resistor Rf, and the other end of resistor Rf is connected to the positive output terminal of the hysteresis comparator; the reference current source module is connected to the negative input terminal of the hysteresis comparator via a resistor R; the temperature detection circuit detects the real-time temperature of the high-voltage integrated circuit and outputs a corresponding voltage signal. When the temperature exceeds or falls below a set threshold voltage, the hysteresis comparator internally controls the high-voltage integrated circuit to disconnect or connect to the power supply. This invention effectively improves the anti-interference capability of the temperature protection circuit, protects the integrated intelligent power module from damage due to high temperatures, and thus improves the reliability and market competitiveness of the intelligent power module.

Description

Technical Field

[0001] This invention relates to the field of intelligent power module technology, and more particularly to a temperature protection circuit based on a hysteresis comparator and an intelligent power module having the same. Background Technology

[0002] With the development of industrial level and science and technology, the pace of upgrading of power electronic products is getting faster and faster, and people's requirements for performance are also getting higher and higher. Among them, temperature detection and temperature protection are important components of today's monolithic integrated intelligent power drive chips. The accuracy of these components largely determines the efficiency and reliability of the application system in the actual application environment. High precision, low power consumption, and easy integration have become important design goals for temperature detection and temperature protection modules. High-voltage integrated intelligent power modules integrate high-voltage power switching devices such as LIGBTs and medium-high voltage high-power MOSFETs. These high-voltage power switching devices usually operate under high voltage and high current, which will result in large switching losses and a continuous increase in internal power density. This can easily cause the internal temperature of the module to rise. As the module temperature rises, the on-resistance of the LIGBT, based on its positive temperature characteristic, also increases, which in turn increases the switching losses of the LIGBT, thus forming a positive feedback. If there are no temperature monitoring measures, the further accumulation of heat will seriously affect the normal operation of the chip, or even cause the module to fail directly.

[0003] Existing temperature protection circuits use comparators for temperature control. When the input temperature-related voltage signal reaches a set threshold voltage, the comparator's output signal flips, cutting off the line between the intelligent power module and the power supply to achieve temperature control. However, traditional comparators are too sensitive; any tiny change near the threshold voltage will cause a jump in the output voltage, leading to false power cut-offs and affecting the normal operation of the equipment. Comparators also have poor anti-interference capabilities and are greatly affected by the accuracy of temperature detection. Therefore, designing a more accurate temperature protection circuit with stronger anti-interference capabilities is of great importance. Summary of the Invention

[0004] This invention proposes a temperature protection circuit based on a hysteresis comparator and an intelligent power module incorporating it, in order to solve the problems of existing temperature protection circuits being easily affected by the accuracy of temperature detection and small voltage changes, having poor anti-interference capabilities, and being unable to provide more precise temperature protection control for intelligent power modules.

[0005] According to one aspect of the present invention, a temperature protection circuit based on a hysteresis comparator is provided, comprising: a reference current source module, a temperature detection circuit, and a hysteresis comparator;

[0006] The reference current source module is connected to the temperature detection circuit, and the temperature detection circuit is connected to the positive input terminal of the hysteresis comparator through resistor R1;

[0007] One end of resistor R1 and the positive input terminal of the hysteresis comparator are connected to one end of resistor Rf, and the other end of resistor Rf is connected to the positive output terminal of the hysteresis comparator.

[0008] The reference current source module is connected to the negative input terminal of the hysteresis comparator via a resistor R;

[0009] The temperature detection circuit is used to detect the real-time temperature of the high-voltage integrated circuit and output a corresponding voltage signal. The hysteresis comparator is used to control the high-voltage integrated circuit to disconnect or connect to the power supply by internally turning on or off when the voltage signal exceeds or falls below a set threshold voltage.

[0010] The reference current source module is connected to resistor R2, and the reference current source module is used to provide a temperature-independent reference current for the hysteresis comparator and temperature detection circuit.

[0011] Preferably, the reference current source module includes: a reference current source circuit and a current correction circuit;

[0012] The current correction circuit includes: resistor R 3a Resistance R 3b MOSFET M3 and transistor Q3;

[0013] The resistor R 3a and resistance R 3b One end is connected to the operational amplifier OP of the reference current source circuit, and the other end is connected to the MOS transistor M3;

[0014] The current correction circuit MOSFET M3 is connected to the reference current source circuit VCC power supply and the reference current source circuit MOSFET M2, respectively.

[0015] The transistor Q3 in the current correction circuit is connected to the resistor R. 3a and resistance R 3b The other end and MOSFET M3;

[0016] The current correction circuit is used to eliminate the nonlinear term in the base voltage of the transistor inside the reference current source circuit, so that the reference current source circuit outputs a reference current with zero temperature coefficient.

[0017] The temperature detection circuit is connected to the reference current source circuit.

[0018] Preferably, the reference current source circuit includes: MOSFETs M1 and M2, operational amplifier OP, and resistor R. 2a R 2bR11 and transistors Q1 and Q2;

[0019] The drain of MOSFET M1 and the drain of MOSFET M2 in the reference current source circuit are connected to the power supply VCC, and the gates of MOSFET M1 and MOSFET M2 are connected to the output terminal of the operational amplifier OP.

[0020] The source (S) of MOSFET M1, the negative input terminal of op-amp OP, and resistor R in the reference current source circuit are... 2a One end is connected to the collector (C) of transistor Q1;

[0021] The source (S) of MOSFET M2, the positive input of op-amp OP, and resistor R in the reference current source circuit are... 2b One end of it is connected to one end of resistor R11;

[0022] The base (B), emitter (E), and resistor R of transistors Q1 and Q2 in the reference current source circuit 2a The other end is connected to resistor R 2b The other end is connected to GND.

[0023] Preferably, the temperature detection circuit includes: a temperature characteristic resistor;

[0024] The temperature characteristic resistor is connected to the reference current source module. The temperature characteristic resistor is used to output a voltage signal corresponding to the temperature after the reference current output by the reference current source module passes through the temperature characteristic resistor.

[0025] Preferably, if the resistance value of either resistor R1 or resistor Rf is set, the resistance value of the other resistor is determined according to formula (1) or (2).

[0026] VotH=(R1 / Rf)(Vref-VOL)+Vref (1);

[0027] VotL=(R1 / Rf)(Vref-VOH)+Vref (2);

[0028] In the formula: VotH and VotL are the turn-on threshold and turn-off threshold in the set threshold voltage; Vref is the reference voltage; VOH and VOL are the high and low level voltages of the hysteresis comparator output.

[0029] Preferably, the reference voltage is determined according to the following formula (3);

[0030] Vref=I REF *R2 (3);

[0031] In the formula: I REF This is the reference current.

[0032] Preferably, the voltage hysteresis of the hysteresis comparator is determined according to the following formula (4);

[0033] VotH-VotL=(R1 / Rf )*(VOH-VOL) (4);

[0034] In the formula: VOH and VOL are the high and low level voltages of the hysteresis comparator output.

[0035] Preferably, the positive output terminal of the hysteresis comparator is connected to one end of resistor R3, and the other end of resistor R3 is connected to power supply VCC.

[0036] According to one aspect of the present invention, a smart power module with a temperature protection circuit is provided, including the temperature protection circuit based on a hysteresis comparator as described above, specifically including: a high-voltage integrated circuit HVIC;

[0037] The HVIC includes: high-side and low-side drive circuits and their corresponding input stage circuits, dead-time generation circuits, pulse generation circuits, level shifting circuits, output circuits, low-side delay circuits, undervoltage protection circuits, current protection ITRIIP circuits, and fault logic protection circuits.

[0038] The temperature protection circuit is connected to the input stage circuits corresponding to the fault logic control circuit, undervoltage protection circuit, high-side drive circuit, dead-zone generation circuit, and pulse generation circuit.

[0039] Preferably, it further includes: an aluminum circuit substrate;

[0040] An insulating layer is provided on the surface of the circuit aluminum substrate, and circuit wiring is provided on the insulating layer;

[0041] The bottom surface of the circuit aluminum substrate has a texture;

[0042] The temperature protection circuit, high-side and low-side drive circuits and their corresponding input stage circuits, dead-zone generation circuit, pulse generation circuit, level shifting circuit, output circuit, low-side delay circuit, undervoltage protection circuit, current protection ITRIIP circuit, and fault logic protection circuit are fixed on the circuit wiring.

[0043] The present invention has at least the following beneficial effects:

[0044] This invention proposes a temperature protection circuit based on a hysteresis comparator and an intelligent power module incorporating it. By employing a reference current source module to output a reference current independent of temperature, the accuracy of temperature detection is improved, avoiding the impact of inaccurate temperature on temperature protection. Simultaneously, by setting up a hysteresis comparator for protection switch control, the hysteresis characteristic of the hysteresis comparator is utilized to effectively improve anti-interference capability, protect the integrated intelligent power module from damage due to high temperature, and thus improve the reliability and market competitiveness of the intelligent power module. Attached Figure Description

[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention and, together with the specification, serve to explain the technical solutions of the present invention.

[0046] Figure 1 A circuit schematic diagram of a hysteresis comparator according to an embodiment of the present invention is shown;

[0047] Figure 2 A schematic diagram of a reference current source circuit according to an embodiment of the present invention is shown;

[0048] Figure 3 A schematic diagram of a temperature detection circuit according to an embodiment of the present invention is shown;

[0049] Figure 4 A connection block diagram of an HVIC component with a temperature protection circuit according to an embodiment of the present invention is shown;

[0050] Figure 5 A circuit diagram of an intelligent power module according to an embodiment of the present invention is shown;

[0051] Figure 6 A schematic diagram of the structure of an intelligent power module according to an embodiment of the present invention is shown;

[0052] Figure 7 The following is illustrated according to an embodiment of the present invention. Figure 6 A cross-sectional view of X-X';

[0053] Figure 8 A schematic diagram of the pin structure according to an embodiment of the present invention is shown.

[0054] In the diagram, 22-intelligent power module, 23-circuit board, 24-insulating layer, 25-circuit wiring, 26-texture, 27-circuit element, 28-metal wire, 29-pin, 31-resin, 33-reinforcing rib. Detailed Implementation

[0055] Various exemplary embodiments, features, and aspects of the present invention will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0056] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0057] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0058] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art will understand that the present invention can be practiced without certain specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art have not been described in detail in order to highlight the spirit of the invention.

[0059] Figure 1 A circuit schematic diagram of a hysteresis comparator according to an embodiment of the present invention is shown; Figure 2 A circuit schematic diagram of a reference current source module according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of a temperature detection circuit based on a hysteresis comparator according to an embodiment of the present invention is shown. Figure 4 A connection block diagram of an HVIC component with a temperature protection circuit according to an embodiment of the present invention is shown; Figure 5 A circuit diagram of an intelligent power module according to an embodiment of the present invention is shown; Figure 6 A schematic diagram of the structure of an intelligent power module according to an embodiment of the present invention is shown; Figure 7 The following is illustrated according to an embodiment of the present invention. Figure 6 A cross-sectional view of X-X'; Figure 8 A schematic diagram of the pin structure according to an embodiment of the present invention is shown. Figure 1-8 As shown, a temperature protection circuit based on a hysteresis comparator includes: a reference current source module, a temperature detection circuit, and a hysteresis comparator; the reference current source module is connected to the temperature detection circuit, and the temperature detection circuit is connected to the positive input terminal of the hysteresis comparator through a resistor R1; one end of the resistor R1 and the positive input terminal of the hysteresis comparator are connected to one end of a resistor Rf, and the other end of the resistor Rf is connected to the positive output terminal of the hysteresis comparator; the reference current source module is connected to the negative input terminal of the hysteresis comparator through a resistor R; the temperature detection circuit is used to detect the real-time temperature of the high-voltage integrated circuit and output a corresponding voltage signal; the hysteresis comparator is used to control the high-voltage integrated circuit to disconnect or connect to the power supply through internal switching when the voltage signal exceeds or falls below a set threshold voltage; the reference current source module is connected to a resistor R2, and the reference current source module is used to provide a temperature-independent reference current for the hysteresis comparator and the temperature detection circuit.

[0060] In this invention, the positive output terminal of the hysteresis comparator is connected to one end of resistor R3, and the other end of resistor R3 is connected to power supply VCC.

[0061] In embodiments of the present invention, such as Figure 1 As shown, the temperature protection circuit based on a hysteresis comparator mainly consists of a hysteresis comparator, a reference current source circuit, and a temperature detection circuit. The reference voltage Vref of the hysteresis comparator is supplied by the reference current source I... REF The circuit, combined with resistor R2, is input to the negative input terminal V- of the hysteresis comparator via resistor R. The output voltage signal V of the temperature detection circuit is... R The positive input terminal V+ of the hysteresis comparator is input through resistor R1. One end of resistor R1, the positive input terminal of the hysteresis comparator, is connected to one end of resistor Rf. The other end of resistor Rf, one end of pull-up resistor R3, is connected to the positive output terminal of the hysteresis comparator. The other end of resistor R3 is connected to VCC.

[0062] The reference current source module outputs a temperature-independent reference current, which is transmitted through the circuit to the temperature detection circuit and the hysteresis comparator. The temperature detection current detects the real-time temperature of the intelligent power module and outputs a voltage signal V corresponding to the temperature. R .

[0063] When the voltage signal V output by the temperature detection circuit R When the input voltage Vot of resistor R1 starts to exceed the set threshold voltage (but not completely), it indicates that the temperature of the smart power module chip is high. In this case, the output voltage of the hysteresis comparator is low, i.e., the output voltage VOL=0V, and the smart power module is disconnected from the power supply. When the input voltage Vot starts to fall below the threshold voltage (but not completely), it indicates that the temperature of the smart power module chip is within the safe temperature range. In this case, the output voltage of the hysteresis comparator is high, i.e., the output voltage VOH=5V, and the smart power module is connected to the power supply.

[0064] In this invention, the reference current source module includes: a reference current source circuit and a current correction circuit; the current correction circuit includes: a resistor R. 3a Resistance R 3b MOSFET M3 and transistor Q3; the resistor R 3a and resistance R 3b One end of the current correction circuit is connected to the operational amplifier OP of the reference current source circuit, and the other end is connected to the MOSFET M3; the MOSFET M3 of the current correction circuit is connected to the VCC power supply of the reference current source circuit and the MOSFET M2 of the reference current source circuit respectively; the transistor Q3 of the current correction circuit is connected to the resistor R respectively. 3a and resistance R 3bThe other end and MOS transistor M3; the current correction circuit is used to eliminate the nonlinear term in the base voltage of the transistor inside the reference current source circuit, so that the reference current source circuit outputs a reference current with zero temperature coefficient; the temperature detection circuit is connected to the reference current source circuit.

[0065] In this invention, the reference current source circuit includes: MOS transistors M1 and M2, operational amplifier OP, and resistor R. 2a R 2b The reference current source circuit includes R11 and transistors Q1 and Q2; the drains of MOSFETs M1 and M2 are connected to the power supply VCC, and the gates of MOSFETs M1 and M2 are connected to the output of the operational amplifier OP; the source of MOSFET M1, the negative input of the operational amplifier OP, and resistor R11 are also connected to the reference current source circuit. 2a One end is connected to the collector (C) of transistor Q1; the source (S) of MOSFET M2, the positive input of operational amplifier OP, and resistor R in the reference current source circuit are connected. 2b One end is connected to one end of resistor R11; the base (B) and emitter (E) of transistors Q1 and Q2 in the reference current source circuit, and resistor R11 are connected to the other end of the reference current source circuit. 2a The other end is connected to resistor R 2b The other end is connected to GND.

[0066] In embodiments of the present invention, such as Figure 2 As shown, the reference current source circuit consists of MOSFETs, operational amplifiers, resistors, and transistors. The drain (D) of PMOS transistor M1 and the drain of PMOS transistor M2 are connected to the power supply VCC. The gates (G) of PMOS transistors M1 and M2 are connected to the output of the operational amplifier (OP). The source (S) of PMOS transistor M1, the negative input of the operational amplifier (OP), and the resistor R... 2a One end is connected to the collector (C) of transistor Q1, and the connection point is denoted as X; the source (S) of PMOS transistor M2, the positive input terminal of op-amp OP, and resistor R 2b One end of the transistor is connected to one end of resistor R11, and the connection point is denoted as Y. The other end of resistor R11 is connected to the collector (C) of transistor Q2. The base (B) and emitter (E) of transistors Q1 and Q2 are connected to resistor R11. 2a The other end is connected to resistor R 2b The other end is connected to GND.

[0067] The current correction circuit includes resistor R 3a and R 3b And transistor Q3; the drains of MOSFET M1, M2, and M3 are connected together to VCC; resistor R 3b One end is connected to the negative input terminal of the operational amplifier (OP), and resistor R 3a One end, R 2b One end is connected to the positive input terminal of the operational amplifier (OP); resistor R3b The other end, R 3a The other end, the source (S) of MOSFET M3, is connected to the collector (C) of transistor Q3; resistor R 2b At the other end, the base (B) and emitter (E) of transistor Q3 are connected to GND; MOSFETs M1 and M2 form a current mirror, and MOSFETs M1 and M3 also form a current mirror; the source (S) of MOSFET M3 is connected to the collector (C) of transistor Q3, and the current is not affected by VCC.

[0068] In this embodiment of the invention, resistor R11 and resistor R 2a Resistance R 3a The resistance value satisfies equations (5-1) and (5-2);

[0069] KlnN / (qR11)=(Vg0-V BE(Tr) ) / (Tr*R 2a (5-1);

[0070] (η-1) / R 2a =1 / R 3a (5-2);

[0071] In the formula: K is the Boltzmann constant, with a value of 1.380 × 10⁻⁶. -23 J / K; N is the ratio of the emitter areas of transistors Q1 and Q2; q is the magnitude of the electron charge, which is 1.602 × 10⁻⁶. -19 C; Vg0 is the potential difference between the conduction band bottom and valence band top of silicon at temperature T=0K; V BE(Tr) η is the voltage at temperature Tr; Tr is the reference temperature; η is a process-related constant.

[0072] The sum of the current I1 (with a positive temperature coefficient) and the current I2 (with a negative temperature coefficient) is subtracted from the resistance R. 3a R 3b Nonlinear term I in current NL This yields a reference current with zero temperature coefficient. The specific working principle is as follows:

[0073] Due to the virtual short and virtual open effects of the operational amplifier OP in the reference current source circuit, the voltage at point X and the voltage at point Y are equal. Combining with equation (6), the positive temperature coefficient current I1 flowing through resistor R11 can be obtained as:

[0074] I1=(V BE1 -V BE2 ) / R11=(KT / (qR11))lnN (6);

[0075] In the formula: K is the Boltzmann constant, with a value of 1.380 × 10⁻⁶. -23J / K; q is the magnitude of the electron charge, which is 1.602 × 10⁻⁶. -19 C; N is the ratio of the emitter areas of the two transistors Q2 and Q1; T is the temperature; V BE2 This is the voltage of Q2.

[0076] Due to resistance R 2a and R 2b With the same resistance, point X (R) 2a Q1, M1, op-amp connection nodes) and Y point (op-amp, R11, M2, R) 2b R 3a If the voltages at the connection nodes are equal, then current flows through resistor R. 2a and R 2b The currents are the same; and after being replicated by current mirrors (M1 and M2), the temperature characteristics of the current flowing through transistor Q1 are the same as those of the current flowing through transistor Q2. From equation (6), it can be seen that they are both P TAT The current, then the base-emitter voltage V of transistor Q2 BE1 for:

[0077] V BE1 =Vg0-(Vg0-V BE(Tr) )T / Tr*(η-1)V NL (7);

[0078] In the formula: Vg0 is the potential difference between the conduction band bottom and valence band top of silicon at T=0K, η is a process-related constant, Tr is the reference temperature, and both T and Tr represent thermodynamic temperature in K; V BE(Tr) V is the voltage at temperature Tr; NL For resistor R 3b The voltage.

[0079] Then in resistor R 2a The current I2 generated above is:

[0080] I2=V BE2 / R 2a =[Vg0-(Vg0-V BE(Tr) )T / Tr*(η-1)V NL ] / R 2a (8);

[0081] Furthermore, due to the replication effect of the current mirror formed by MOSFETs M1 and M3, the current flowing through transistor Q3 is a current I with zero temperature coefficient. REF3 The base-emitter voltage V of transistor Q3 BE3 for:

[0082] V BE3 =Vg0-(Vg0-V BE(Tr) )T / Tr*ηVNL (9);

[0083] Combining equations (7) and (9), the flow through resistor R can be obtained. 3a Current I on NL for:

[0084] I NL =(V BE2 -V BE3 ) / R 3a =V NL / R 3a (10);

[0085] Combining equations (6), (8), and (10), the reference current I with zero temperature coefficient can be obtained. REF for:

[0086] I REF =(KT / (qR11))lnN+[Vg0-(Vg0-V BE(Tr) )T / Tr*(η-1)V NL ] / R 2a +V NL / R 3a =Vg0 / R 2a (11);

[0087] According to equation (11), as long as equations (5-1) and (5-2) are satisfied, the values ​​of resistor R11 and resistor R can be obtained. 2a Resistance R 3a The resistance value at that time is used to enable the reference current source circuit to output a reference current with zero temperature coefficient, which is independent of temperature. Because the output is a reference current with zero temperature coefficient, the temperature detection circuit can detect more accurately and prevent the hysteresis comparator from malfunctioning due to inaccurate temperature. At the same time, the reference current with zero temperature coefficient powering the hysteresis comparator can improve the accuracy of the hysteresis comparator's temperature sampling.

[0088] In this invention, the temperature detection circuit includes a temperature characteristic resistor R(T); the temperature characteristic resistor R(T) is connected to the reference current source module, and the temperature characteristic resistor R(T) is used to output a voltage signal corresponding to the temperature after the reference current output by the reference current source module passes through the temperature characteristic resistor R(T).

[0089] In embodiments of the present invention, such as Figure 3 As shown, the temperature characteristic resistor R(T) is a Poly resistor or an N-Well resistor.

[0090] The temperature detection circuit mainly consists of a constant current I that is independent of absolute temperature. REFIt consists of a poly resistor with temperature-sensitive characteristics. A constant current I... REF Provided by a reference current source circuit and a current correction circuit, when the current I output through the reference current source circuit and the current correction circuit... REF A voltage V is obtained by flowing through a poly resistor with temperature characteristics, i.e., a temperature sensing resistor R(T). R V R This is the voltage corresponding to the real-time temperature when driving the intelligent power module. Based on the voltage signal V... R The size can determine the corresponding temperature value, that is, the real-time temperature of the intelligent power module.

[0091] In semiconductors, integrated resistors typically exhibit a temperature dependence on ambient temperature within a certain temperature range. This relationship is generally expressed using the temperature coefficient of resistance (TCR), α. TCR This refers to the relative change in resistance for every 1°C change in temperature, expressed in ppm / °C. Typically, the correlation between resistance and temperature can be expressed as:

[0092] R(T) = R0(1 + α) TCR1 (T-Tr)+α TCR2 (T-Tr) 2 (12);

[0093] In the formula: R0 is the resistance value at temperature T=Tr, α TCR1 Let α be the first-order temperature coefficient of the resistance. TCR2 Tr represents the second-order temperature coefficient of resistance, Tr represents the reference temperature, and both T and Tr represent thermodynamic temperature, with units of K.

[0094] Among poly resistors with positive / negative temperature coefficients and N-Well resistors with positive temperature coefficients, poly resistors are resistors made of the poly layer used as the gate of a MOSFET, and are divided into low-resistance poly resistors and high-resistance poly resistors. The temperature coefficient of a poly resistor can be positive or negative, mainly depending on the implanted impurity ions (such as P+ or N+). A larger temperature coefficient can be obtained by reducing the doping concentration of P+ / N+ impurity ions. For high-resistance poly resistors, due to their lower doping concentration, they typically have a larger negative temperature coefficient. N-Well resistors, on the other hand, are resistors implemented using N-Well technology on a P-substrate. They typically have a larger sheet resistance value. Because N-Well resistors generally have a very low P+ doping concentration, they have a larger positive temperature coefficient. And like poly resistors, a larger positive temperature coefficient can be obtained by reducing the P+ implantation concentration. High-resistance poly resistors have a negative temperature coefficient of -3050 ppm / ℃, while N-Well resistors have a positive temperature coefficient of 5600 ppm / ℃. Therefore, in integrated circuit technology, both poly resistors and N-Well resistors can be used as temperature sensing devices in temperature detection circuits to achieve temperature detection.

[0095] This invention uses a high-resistance Poly resistor with a negative temperature coefficient as the temperature sensing device in a temperature detection circuit to achieve temperature detection.

[0096] Based on the above, we get V R =I REF *R=I REF *R0(1+α TCR1 (T-Tr)+α TCR2 (T-Tr) 2 );

[0097] Due to the second temperature coefficient α of the resistance TCR2 It is very small, typically a few ppm / ℃, so compared to its first-order temperature coefficient α TCR1 α TCR2 If it can be ignored, the final calculation formula for the real-time temperature T of the intelligent power module is shown in equation (13).

[0098] V R =I REF *R0(1+α TCR1 (T-Tr)) (13;

[0099] In the formula: V R I is the voltage generated through resistor R(T); REFThe constant current output after passing through the reference current source circuit and the current correction circuit (reference current); R0 is the resistance value at temperature T=Tr, where Tr is the reference temperature; α TCR1 is the first-order temperature coefficient of the resistance.

[0100] In this invention, the resistance value of either resistor R1 or resistor Rf is set, and the resistance value of the other resistor is determined according to formula (1) or (2).

[0101] VotH=(R1 / Rf)(Vref-VOL)+Vref (1);

[0102] VotL=(R1 / Rf)(Vref-VOH)+Vref (2);

[0103] In the formula: VotH and VotL are the turn-on threshold and turn-off threshold in the set threshold voltage; Vref is the reference voltage; VOH and VOL are the high and low level voltages of the hysteresis comparator output.

[0104] In this embodiment of the invention, the threshold voltage includes an on-threshold and an off-threshold. Based on the "virtual short" and "virtual open" operations of the operational amplifier (OP), the calculation formulas for the threshold voltage of the temperature protection circuit of the hysteresis comparator can be obtained as shown in equations (1) and (2).

[0105] When the input voltage Vot exceeds the turn-on threshold, the hysteresis comparator outputs a low-level voltage (VOL = 0V) as a temperature protection signal, shutting off the HVIC output. When the input voltage Vot falls below the turn-off threshold, the hysteresis comparator outputs a high-level voltage (VOH = 5V) as a temperature protection signal, restoring the HVIC output. The turn-on and turn-off thresholds are set based on the voltage values ​​corresponding to the highest permissible temperature during operation of the intelligent power module.

[0106] Based on the set turn-on threshold and turn-off threshold, and the resistance value of resistor R1 or Rf, substitute into equation (1) or (2) to calculate the resistance value of another resistor R1 or Rf, and configure the circuit according to the calculated resistance value.

[0107] In this invention, the reference voltage is determined according to the following formula (3);

[0108] Vref=I REF *R2 (3);

[0109] In the formula: I REF This is the reference current.

[0110] In this embodiment of the invention, the reference current required for the hysteresis comparator output by the reference current source circuit to run can be calculated according to equation (3).

[0111] In this invention, the voltage hysteresis (hysteresis width) of the hysteresis comparator is determined according to the following formula (4);

[0112] VotH-VotL=(R1 / Rf )*(VOH-VOL) (4);

[0113] In the formula: VOH and VOL are the high and low level voltages of the hysteresis comparator output.

[0114] In this embodiment of the invention, when the input voltage reaches the set threshold voltage, the comparator output signal flips. However, any small change near the threshold voltage will cause a jump in the output voltage. Therefore, although the comparator is relatively sensitive, its anti-interference capability is poor. In contrast, the hysteresis comparator has hysteresis characteristics. It only flips when the voltage rises to a certain level, i.e., the set threshold, thus having a certain inertia and therefore a certain anti-interference capability.

[0115] In this invention, a smart power module with a temperature protection circuit is also proposed, including the temperature protection circuit based on a hysteresis comparator as described above, specifically including: a high-voltage integrated circuit (HVIC); wherein, the HVIC includes: high-side and low-side drive circuits and their corresponding input stage circuits, dead-time generation circuits, pulse generation circuits, level shifting circuits, output circuits, low-side delay circuits, undervoltage protection circuits, current protection ITRIIP circuits, and fault logic protection circuits; the temperature protection circuit is connected to the fault logic control circuit, the undervoltage protection circuit, the input stage circuits corresponding to the high-side drive circuit, the dead-time generation circuit, and the pulse generation circuit.

[0116] In embodiments of the present invention, such as Figure 4 As shown, the temperature protection circuit based on the hysteresis comparator drives the HVIC, which is... Figure 5 The 0101 in the diagram includes three channels of high-side drive circuit: HIN1, HIN2, and HIN3, and three channels of low-side drive circuit: LIN1, LIN2, and LIN3.

[0117] The input drive signals of HIN1, HIN2, and HIN3 pass through the input stage circuit, dead-time generation circuit, and pulse generation circuit to output the OUT_H pulse signal. The rising and falling edges of the OUT_H pulse signal are used to output the SET and RESET short pulse signals, respectively. The low-to-high voltage conversion is achieved through the level shifting circuit. The high-side drive pulse signals HHO and HLO are output through the output circuit.

[0118] The input drive signals LIN1, LIN2, and LIN3 pass through the input stage circuit, dead-time generation circuit, and output OUT_L pulse signal; after passing through the low-side delay circuit, the consistency of high and low-side drive signals is achieved; and after passing through the output circuit, the low-side drive pulse signals LHO and LLO are output.

[0119] Vot is the output signal of the temperature detection circuit driving the HVIC. This signal reflects the real-time temperature status of the driving HVIC, and the application system can design reasonable temperature protection based on Vot.

[0120] The drive signals HO and LO are protected by undervoltage protection circuit, ITRIP current protection circuit, temperature protection circuit, and fault logic circuit (fault output circuit). The fault output circuit 0114 outputs a fault signal.

[0121] like Figure 5As shown, the HO1, HO2, HO3, LO1, LO2, and LO3 ports of the integrated 6-channel driver HVIC0101 are connected to the G ports of GaN FET1, GaN FET3, GaN FET5, GaN FET2, GaN FET4, and GaN FET6, respectively. The D ports of GaN FET1, GaN FET3, and GaN FET5 are connected together, leading out pin 1 (VCC) of the (action) module. The S terminal of GaN FET1, the D terminal of GaN FET2, the U,VS1 of the 6-channel driver HVIC0101, and one end of the bootstrap capacitor C1 are connected to the anode of the bootstrap clamping Zener diode ZD1, leading out as pin 6 (U,VS1) of the module. The S terminal of GaN FET3, the D terminal of GaN FET4, and the 6-channel driver HVIC0101 are connected together. The V, VS2 pins of the 0101 and one end of the bootstrap capacitor C2 are connected to the anode of the bootstrap clamping Zener diode ZD2, forming pin 8 (V, VS2) of the module. The source (S) of GaN FET5, the drain (D) of GaN FET6, the W, VS3 pins of the 6-channel driver HVIC0101, and one end of the bootstrap capacitor C3 are connected to the anode of the bootstrap clamping Zener diode ZD3, forming pin 10 (W, VS3) of the module. The source (S) of GaN FET2 forms pin 2 (U-) of the module. The source (S) of GaN FET4 forms pin 3 (V-) of the module. The source (S) of GaN FET6 forms pin 4 (W-) of the module. The VB1 pin of the 6-channel driver HVIC0101 and the other end of the bootstrap capacitor C1 are connected to the cathode of the bootstrap clamping Zener diode ZD1, forming pin 5 (VB1) of the module. The other end of VB2 of the 0101 and the bootstrap capacitor C2 are connected to the cathode of the bootstrap clamping Zener diode ZD2, and brought out as pin 7 (VB2) of the module; the other end of VB3 of the 6-channel driver HVIC 0101 and the bootstrap capacitor C3 are connected to the cathode of the bootstrap clamping Zener diode ZD3, and brought out as pin 9 (VB3) of the module; the HIN1 of the 6-channel driver HVIC 0101 is brought out as pin 11 (HIN1) of the module; the HIN2 of the 6-channel driver HVIC 0101 is brought out as pin 12 (HIN2) of the module; the HIN3 of the 6-channel driver HVIC 0101 is brought out as pin 13 (HIN3) of the module; the LIN1 of the 6-channel driver HVIC 0101 is brought out as pin 14 (LIN1) of the module; the LIN2 of the 6-channel driver HVIC 0101 is brought out as pin 15 (LIN2) of the module; the 6-channel driver HVIC... The LIN3 pin of the 0101 is used as the LIN3 port, pin 16 of the module; the Vot pin of the 6-channel HVIC 0101 is used as the Vot port, pin 21 of the module.The ITRIP of the 6-channel driver HVIC 0101 is connected to one end of the filter capacitor C4, and this connection is used as pin 18 of the IPM (ITRIP port). The other end of the filter capacitor C4 is connected to VSS. A filter capacitor C5 is connected between VDD and VSS. VDD is used as pin 19 of the IPM (VDD port), and VSS is used as pin 20 of the IPM (VSS port).

[0122] The invention further includes: an aluminum circuit substrate; an insulating layer is disposed on the surface of the aluminum circuit substrate, and circuit wiring is disposed on the insulating layer; the bottom surface of the aluminum circuit substrate has a texture; the temperature protection circuit, the high-side and low-side driving circuits and their corresponding input stage circuits, dead-zone generation circuits, pulse generation circuits, level shifting circuits, output circuits, low-side delay circuits, undervoltage protection circuits, current protection ITRIIP circuits and fault logic protection circuits are fixed on the circuit wiring.

[0123] In embodiments of the present invention, such as Figure 7 The image shows a cross-sectional view of a smart power module including an integrated hysteresis comparator-based temperature protection circuit (HVIC). It includes: a circuit aluminum substrate 23; and circuit wiring 25 formed on an insulating layer 24 disposed on the surface of the circuit aluminum substrate 23, the overall circuit wiring as shown... Figure 1-4 As shown.

[0124] The bottom surface of the circuit aluminum substrate 23 has an uneven texture 26; circuit elements 27 are fixed on the circuit wiring 25; metal wires 28 connect the circuit elements 27 and the circuit wiring 25; pins 29 are connected to the circuit wiring 25, and the rest is covered by an electroplating layer; the entire intelligent power module 22 is sealed with sealing resin 31.

[0125] The manufacturing method of the intelligent power module 22 is as follows: An aluminum material is formed into a circuit board 23 of appropriate size, and a texture 26 is formed on its back side through laser etching, polishing, etc. An insulating layer 24 is set on the surface of the circuit board 23, and copper foil is formed on the insulating layer 24. Circuit wiring 25 is formed on the copper foil through etching. Solder paste is applied to specific locations of the circuit wiring 25. A copper material is formed into an appropriate shape and surface-plated to serve as pins 29, such as… Figure 8As shown, to prevent electrostatic damage to circuit element 27 during subsequent processing, specific positions of pins 29 are connected by reinforcing ribs 33. Circuit element 27 and pins 29 are placed on solder paste; the solder paste is cured to fix circuit element 27 and pins 29 to circuit wiring 25. Residual flux on the circuit board 23 is removed by cleaning methods such as spraying or ultrasonic cleaning. A connection is formed between circuit element 27 and circuit wiring 25 using bonding wires. If the circuit board 23 needs to be connected to ground potential, the process further includes drilling through the insulating layer 24 via a through-hole and forming a connection between the ground potential of the circuit wiring 25 and the circuit board 23 using bonding wires. The hardware is sealed using injection molding with thermoplastic resin or transfer molding with thermosetting resin, such as... Figure 6 As shown. The reinforcing rib 33 of pin 29 is cut off and shaped as required. The intelligent power module undergoes necessary tests; those that pass the tests become intelligent power modules with a temperature protection circuit based on a hysteresis comparator.

[0126] Meanwhile, the intelligent power module of this invention uses third-generation semiconductor devices, GaN FETs, as its switching devices. GaN FETs are third-generation semiconductors, and their built-in FRD (freewheeling diode chip) eliminates the need for anti-parallel FRDs compared to Si-based IGBTs. The advantages of third-generation GaN FETs over silicon-based IGBTs and MOSFETs include superior breakdown capability, higher electron density and mobility, and higher operating temperature. This results in lower losses and higher switching frequencies: lower losses reduce heat generation from conduction resistance, helping to reduce the size of the application module. Furthermore, GaN FETs have a smaller Qg, allowing for easy frequency increases and reduced drive losses. Compared to silicon-based IGBTs, gallium nitride crystals have stronger chemical bonds, allowing them to withstand electric fields many times higher than silicon devices without collapse. This means we can shorten the distance between the transistor terminals by ten times. This results in lower resistive losses and shorter electron switching times. In summary, gallium nitride devices offer advantages such as fast switching, low power consumption, and low cost, making them ideal for high-performance integrated power modules.

[0127] It is understood that the various embodiments mentioned above in this invention can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this invention will not elaborate further.

[0128] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0129] If an abnormal situation occurs during the operation of the intelligent power module, its internal temperature may rise sharply. If the temperature detection is inaccurate at this time, that is, the output value of the temperature detection module differs greatly from the actual value, it will cause a series of malfunctions in the microcontroller that receives the temperature signal at the front end of the system, reducing the system's working efficiency. If the protection circuit fails to make a corresponding protection response in time, the heat will accumulate further, damaging the reliability of the module and ultimately causing the module to fail.

[0130] This invention designs a temperature protection circuit and an intelligent power module based on a hysteresis comparator. The high-precision temperature detection circuit primarily uses a low-temperature drift coefficient reference source to provide a constant current Iref, improving the accuracy of temperature detection and the sampling accuracy of the hysteresis comparator. A precise real-time temperature is acquired through a temperature detection resistor and converted into a voltage input. This voltage is compared with a temperature protection threshold by the hysteresis comparator-based temperature protection circuit. The temperature protection circuit utilizes the hysteresis characteristic of the comparator for temperature protection. When the internal temperature of the intelligent power module exceeds the temperature corresponding to the turn-on threshold VotH, the hysteresis comparator's temperature protection circuit outputs a temperature protection signal to shut down the module output, protecting the module and its application system. When the internal temperature of the intelligent power module drops to the temperature corresponding to the turn-off threshold VotL, the hysteresis comparator's temperature protection circuit outputs a temperature protection signal to restore the module output, allowing the module and its application system to resume normal operation. This hysteresis comparator-based temperature protection circuit can protect the integrated intelligent power module and its application system from damage caused by high temperatures, thereby improving the reliability and market competitiveness of the intelligent power module.

[0131] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A temperature protection circuit based on a hysteresis comparator, characterized in that, include: Reference current source module, temperature detection circuit, and hysteresis comparator; The reference current source module is connected to the temperature detection circuit, and the temperature detection circuit is connected to the positive input terminal of the hysteresis comparator through resistor R1; The reference current source module includes: a reference current source circuit and a current correction circuit; The current correction circuit includes: resistor R 3a Resistance R 3b MOSFET M3 and transistor Q3; resistor R 3a and resistance R 3b One end of the current correction circuit is connected to the operational amplifier OP of the reference current source circuit, and the other end is connected to the MOSFET M3; the MOSFET M3 of the current correction circuit is connected to the VCC power supply of the reference current source circuit and the MOSFET M2 of the reference current source circuit respectively; the transistor Q3 of the current correction circuit is connected to the resistor R respectively. 3a and resistance R 3b The other end and MOSFET M3; The reference current source circuit includes: MOSFETs M1 and M2, operational amplifier OP, and resistor R. 2a R 2b R11 and transistors Q1 and Q2; the drains of MOSFETs M1 and M2 are connected to the power supply VCC, and the gates of MOSFETs M1 and M2 are connected to the output of the operational amplifier (OP); the source of MOSFET M1, the negative input of the OP, and resistor R... 2a One end is connected to the collector (C) of transistor Q1; the source (S) of MOSFET M2, the positive input of op-amp OP, and resistor R 2b One end is connected to one end of resistor R11; the base (B) and emitter (E) of transistors Q1 and Q2 are connected to resistor R11. 2a The other end is connected to resistor R 2b The other end is connected to GND; The resistor R11, resistor R 2a Resistance R 3a The resistance value satisfies equations (5-1) and (5-2); KlnN / (qR11)=(Vg0-V BE(Tr) ) / (Tr*R 2a ) (5-1); (n-1) / R 2a =1 / R 3a (5-2); In the formula: K is the Boltzmann constant, with a value of 1.380 × 10⁻⁶. -23 J / K; N is the ratio of the emitter areas of transistors Q1 and Q2; q is the magnitude of the electron charge, which is 1.602 × 10⁻⁶. -19 C; Vg0 is the potential difference between the conduction band bottom and valence band top of silicon at temperature T=0K; V BE(Tr) η is the voltage at temperature Tr; Tr is the reference temperature; η is a process-related constant. One end of resistor R1 and the positive input terminal of the hysteresis comparator are connected to one end of resistor Rf, and the other end of resistor Rf is connected to the positive output terminal of the hysteresis comparator. The reference current source module is connected to the negative input terminal of the hysteresis comparator via a resistor R; The temperature detection circuit is used to detect the real-time temperature of the high-voltage integrated circuit and output a corresponding voltage signal. The hysteresis comparator is used to control the high-voltage integrated circuit to disconnect or connect to the power supply when the voltage signal exceeds or falls below a set threshold voltage. The reference current source module is connected to resistor R2, and the reference current source module is used to provide a temperature-independent reference current for the hysteresis comparator and temperature detection circuit.

2. The temperature protection circuit based on a hysteresis comparator according to claim 1, characterized in that: The current correction circuit is used to eliminate the nonlinear term in the base voltage of the transistor inside the reference current source circuit, so that the reference current source circuit outputs a reference current with zero temperature coefficient. The temperature detection circuit is connected to the reference current source circuit.

3. The temperature protection circuit based on a hysteresis comparator according to claim 1, characterized in that, The temperature detection circuit includes: a temperature-sensitive resistor; The temperature characteristic resistor is connected to the reference current source module. The temperature characteristic resistor is used to output a voltage signal corresponding to the temperature after the reference current output by the reference current source module passes through the temperature characteristic resistor.

4. The temperature protection circuit based on a hysteresis comparator according to claim 1, characterized in that: If the resistance value of either resistor R1 or resistor Rf is set, the resistance value of the other resistor is determined according to formula (1) or (2). VotH=(R1 / Rf)(Vref-VOL)+Vref (1); VotL=(R1 / Rf)(Vref-VOH)+Vref (2); In the formula: VotH and VotL are the turn-on threshold and turn-off threshold in the set threshold voltage; Vref is the reference voltage; VOH and VOL are the high and low level voltages of the hysteresis comparator output.

5. The temperature protection circuit based on a hysteresis comparator according to claim 4, characterized in that: The reference voltage is determined according to the following formula (3); Vref=I REF *R2 (3); In the formula: I REF This is the reference current.

6. The temperature protection circuit based on a hysteresis comparator according to claim 4, characterized in that: The voltage hysteresis of the hysteresis comparator is determined according to the following formula (4); VotH-VotL=(R1 / Rf )*(VOH-VOL) (4); In the formula: VOH and VOL are the high and low level voltages of the hysteresis comparator output.

7. The temperature protection circuit based on a hysteresis comparator according to any one of claims 1-6, characterized in that: The positive output of the hysteresis comparator is connected to one end of resistor R3, and the other end of resistor R3 is connected to the power supply VCC.

8. A smart power module with a temperature protection circuit, comprising the temperature protection circuit based on a hysteresis comparator as described in any one of claims 1-7, characterized in that, Specifically, it includes: High-voltage integrated circuit HVIC; The HVIC includes: high-side and low-side drive circuits and their corresponding input stage circuits, dead-time generation circuits, pulse generation circuits, level shifting circuits, output circuits, low-side delay circuits, undervoltage protection circuits, current protection ITRIIP circuits, and fault logic protection circuits. The temperature protection circuit is connected to the input stage circuits corresponding to the fault logic control circuit, undervoltage protection circuit, high-side drive circuit, dead-zone generation circuit, and pulse generation circuit.

9. The intelligent power module with temperature protection circuit according to claim 8, characterized in that, Also includes: Aluminum substrate for circuitry; An insulating layer is provided on the surface of the circuit aluminum substrate, and circuit wiring is provided on the insulating layer; The bottom surface of the circuit aluminum substrate has a texture; The temperature protection circuit, high-side and low-side drive circuits and their corresponding input stage circuits, dead-zone generation circuit, pulse generation circuit, level shifting circuit, output circuit, low-side delay circuit, undervoltage protection circuit, current protection ITRIIP circuit, and fault logic protection circuit are fixed on the circuit wiring.

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