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

Abstract

The invention relates to the technical field of intelligent power modules, in particular to a temperature protection circuit based on a hysteresis comparator and an intelligent power module with the same, and the circuit is characterized in that a reference current source module is connected with a temperature detection circuit, and the temperature detection circuit is connected with the positive input end of the hysteresis comparator through a resistor R1; one end of the resistor R1 and the positive input end of the hysteresis comparator are connected with one end of the resistor Rf, and the other end of the resistor Rf is connected with the positive output end of the hysteresis comparator; the reference current source module is connected with the negative input end of the hysteresis comparator through a resistor R; the temperature detection circuit detects the real-time temperature of the high-voltage integrated circuit and outputs a corresponding voltage signal, and when the real-time temperature exceeds or is lower than a set threshold voltage, the hysteresis comparator controls the high-voltage integrated circuit to be disconnected or connected with the power supply through internal connection or disconnection. According to the invention, the anti-interference capability of the temperature protection circuit can be effectively improved, the integrated intelligent power module is protected from being damaged by high temperature, and the reliability and market competitiveness of the intelligent power module are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent power modules, and in particular to a temperature protection circuit based on a hysteresis comparator and an intelligent power module having the same. 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, temperature detection and temperature protection are important components of today's monolithic integrated intelligent power driver chips. The accuracy of temperature detection and temperature protection directly determines the efficiency and reliability of its application system in the actual application environment to a large extent. High precision, low power consumption and easy integration have become important design goals of temperature detection and temperature protection modules. High-voltage integrated intelligent power modules integrate high-voltage power switching devices such as LIGBT, medium and high-voltage high-power MOSFET, and these high-voltage power switching devices usually work under high voltage and high current, which will cause them to have large switching losses, causing the internal power density to continue to increase, and it is easy to increase the temperature inside the module. Due to the increase in module temperature, the on-resistance of LIGBT is based on its positive temperature characteristics, and its resistance value increases accordingly, which in turn increases the switching loss of LIGBT, thus forming a positive feedback. If there is no temperature monitoring measure, the further accumulation of heat will seriously affect the normal operation of the chip, and even cause the module to fail directly.

[0003] The existing temperature protection circuit uses a comparator for temperature control. When the input voltage signal related to temperature reaches the set threshold voltage, the output signal of the comparator will flip, cutting off the line between the intelligent power module and the power supply to achieve the purpose of temperature control. However, the traditional comparator is too sensitive. Any slight change near the threshold voltage will cause a jump in the output voltage, causing the power supply to be cut off by mistake, affecting the normal operation of the equipment. The comparator has poor anti-interference ability and is greatly affected by the temperature detection accuracy. Therefore, it is of great significance to design a temperature protection circuit with strong anti-interference ability and more accuracy. Summary of the invention

[0004] The present invention proposes a temperature protection circuit based on a hysteresis comparator and an intelligent power module equipped with the same, so as to solve the problem that the existing temperature protection circuit is easily affected by temperature detection accuracy and slight voltage changes, has poor anti-interference ability, and cannot perform more accurate temperature protection control on the intelligent power module.

[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 the resistor R1;

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

[0008] The reference current source module is connected to the negative input terminal of the hysteresis comparator through 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, and the hysteresis comparator is used to control the high-voltage integrated circuit to be disconnected or connected to the power supply by internal opening or closing when the voltage signal exceeds or falls below a set threshold voltage;

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

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

[0012] The current correction circuit includes: a resistor R 3a , resistor R 3b , MOS tube M3 and transistor Q3;

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

[0014] The current correction circuit MOS tube M3 is respectively connected to the reference current source circuit VCC power supply and the reference current source circuit MOS tube M2;

[0015] The current correction circuit transistor Q3 is connected to the resistor R 3a and resistor R 3b The other end and MOS tube 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 a zero temperature coefficient;

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

[0018] Preferably, the reference current source circuit includes: MOS tubes M1, M2, operational amplifier OP, resistor R 2a , R 2b, R11 and transistor group Q1, Q2;

[0019] The D pole of the MOS tube M1 and the D pole of the MOS tube M2 of the reference current source circuit are connected to the power supply VCC, and the G pole of the MOS tube M1 and the G pole of the MOS tube M2 are connected to the output end of the operational amplifier OP;

[0020] The S pole of the MOS tube M1 of the reference current source circuit, the negative input terminal of the operational amplifier OP, the resistor R 2a One end is connected to the C pole of transistor Q1;

[0021] The S pole of the MOS tube M2 of the reference current source circuit, the positive input terminal of the operational amplifier OP, the resistor R 2b One end of is connected to one end of resistor R11;

[0022] The reference current source circuit has the B pole, E pole of transistors Q1 and Q2, and resistor R 2a The other end of the resistor R 2b Connect the other end to GND.

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

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

[0025] Preferably, the resistance value of any one of the resistor R1 or the resistor Rf is set, and 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] Where: 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 voltages of the high and low levels output by the hysteresis comparator.

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

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

[0031] Where: I REF 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] Where: VOH and VOL are the high and low level voltages output by the hysteresis comparator.

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

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

[0037] Wherein, the HVIC includes: high-side and low-side driving circuits and their corresponding input stage circuits, dead zone generating circuits, pulse generating circuits, level shifting circuits, output circuits, low-side delay circuits, undervoltage protection circuits, current protection ITRIP circuits and fault logic protection circuits;

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

[0039] Preferably, it also includes: a circuit aluminum substrate;

[0040] An insulating layer is arranged on the surface of the circuit aluminum substrate, and circuit wiring is arranged 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 driving circuits and their corresponding input stage circuits, dead zone generating circuits, pulse generating circuits, level shifting circuits, output circuits, low-side delay circuits, undervoltage protection circuits, current protection ITRIP circuits and fault logic protection circuits are fixed on the circuit wiring.

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

[0044] The present invention proposes a temperature protection circuit based on a hysteresis comparator and an intelligent power module having the same. The temperature detection accuracy is improved by adopting a reference current source module to output a reference current that is independent of temperature, thereby avoiding the influence of inaccurate temperature on temperature protection. At the same time, a hysteresis comparator is set to control the protection switch, and the hysteresis characteristics of the hysteresis comparator are utilized to effectively improve the anti-interference ability, protect the integrated intelligent power module from damage due to high temperature, and thus improve the reliability of the intelligent power module and its market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used 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 block diagram of the connection of HVIC components 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 showing the structure of an intelligent power module according to an embodiment of the present invention is shown;

[0052] Figure 7 The embodiment of the present invention is shown along Figure 6 A cross-sectional view taken along the line X-X';

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

[0054] In the figure, 22 - intelligent power module, 23 - circuit substrate, 24 - insulating layer, 25 - circuit wiring, 26 - texture, 27 - circuit element, 28 - metal wire, 29 - pin, 31 - resin, and 33 - reinforcing rib. DETAILED DESCRIPTION

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

[0056] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0057] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0058] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present 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 block diagram of the connection of HVIC components 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 showing the structure of an intelligent power module according to an embodiment of the present invention is shown; Figure 7 The embodiment of the present invention is shown along Figure 6 A cross-sectional view taken along the line X-X'; Figure 8 FIG. 2 shows a schematic diagram of the structure of the pins according to an embodiment of the present invention. 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 end of the hysteresis comparator through a resistor R1; one end of the resistor R1 and the positive input end 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 end of the hysteresis comparator; the reference current source module is connected to the negative input end 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, and the hysteresis comparator is used to control the high-voltage integrated circuit to be disconnected or connected to the power supply by internal opening or closing when the voltage signal exceeds or is lower than 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 reference current that is independent of temperature for the hysteresis comparator and the temperature detection circuit.

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

[0061] In the embodiment of the present invention, Figure 1 As shown in FIG. 1 , the temperature protection circuit based on the 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 determined by the reference current source I REF The output voltage signal V of the temperature detection circuit is obtained by combining the circuit and the resistor R2, and inputting the negative input terminal V- of the hysteresis comparator through the resistor R. R The positive input terminal V+ of the hysteresis comparator is input through the resistor R1, one end of the resistor R1 and the positive input terminal of the hysteresis comparator are connected to one end of the resistor Rf, the other end of the resistor Rf and one end of the pull-up resistor R3 are connected to the positive output terminal of the hysteresis comparator, and the other end of the resistor R3 is connected to VCC.

[0062] The reference current source module outputs a reference current that is independent of temperature and is transmitted to the temperature detection circuit and the hysteresis comparator through the line; 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 temperature detection circuit outputs a voltage signal V R , that is, when the input voltage Vot of the resistor R1 begins to be higher than the set threshold voltage (but not completely higher), it means that the temperature of the intelligent power module chip is high at this time, then the hysteresis comparator output voltage is low level, that is, the output voltage VOL=0V, and the intelligent power module is disconnected from the power supply; when the input voltage Vot begins to be lower than the threshold voltage (but not completely lower than), it means that the temperature of the intelligent power module chip is within the safe temperature, then the hysteresis comparator output voltage is high level, that is, the output voltage VOH=5V, and the intelligent power module is connected to the power supply.

[0064] In the present 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 , resistor R 3b , MOS tube M3 and transistor Q3; the resistor R 3a and resistor R 3b One end of the reference current source circuit operational amplifier OP is connected, and the other end is connected to the MOS tube M3; the current correction circuit MOS tube M3 is respectively connected to the reference current source circuit VCC power supply and the reference current source circuit MOS tube M2; the current correction circuit transistor Q3 is respectively connected to the resistor R 3a and resistor R 3bThe other end and the MOS tube 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 a zero temperature coefficient; the temperature detection circuit is connected to the reference current source circuit.

[0065] In the present invention, the reference current source circuit includes: MOS tubes M1, M2, operational amplifier OP, resistor R 2a , R 2b , R11 and transistor groups Q1, Q2; the D pole of the MOS tube M1 of the reference current source circuit and the D pole of the MOS tube M2 are connected to the power supply VCC, the G pole of the MOS tube M1 and the G pole of the MOS tube M2 are connected to the output end of the operational amplifier OP; the S pole of the MOS tube M1 of the reference current source circuit, the negative input end of the operational amplifier OP, the resistor R 2a One end of the reference current source circuit MOS tube M2 is connected to the C pole of the transistor Q1; the S pole of the reference current source circuit MOS tube M2, the positive input terminal of the operational amplifier OP, the resistor R 2b The reference current source circuit transistors Q1, Q2, the B pole, the E pole, the resistor R 2a The other end of the resistor R 2b Connect the other end to GND.

[0066] In the embodiment of the present invention, Figure 2 As shown in FIG. 1 , the reference current source circuit is composed of a MOS tube, an operational amplifier, a resistor, and a triode, wherein the D pole of the PMOS tube M1 and the D pole of the PMOS tube M2 are connected to the power supply VCC; the G pole of the PMOS tube M1 and the G pole of the PMOS tube M2 are connected to the output end of the operational amplifier OP; the S pole of the PMOS tube M1, the negative input end of the operational amplifier OP, and the resistor R 2a One end is connected to the C pole of transistor Q1, and the connection point is marked as X; the S pole of PMOS tube M2, the positive input terminal of op amp OP, and the resistor R 2b One end of the transistor is connected to one end of the resistor R11, and the connection point is marked as Y. The other end of the resistor R11 is connected to the C pole of Q2. The B pole and E pole of the transistors Q1 and Q2, and the resistor R 2a The other end of the resistor R 2b The other end is connected to GND.

[0067] The current correction circuit includes a resistor R 3a and R 3b And transistor Q3; the D pole of MOS tube M1, the D pole of MOS tube M2 and the D pole of MOS tube M3 are connected together to VCC; the resistor R 3b One end is connected to the negative input terminal of the op amp OP, and the resistor R 3a One end, R 2b One end of the resistor R is connected to the positive input terminal of the op amp OP;3b The other end, R 3a The other end of the resistor R 2b The other end of the transistor Q3 and the B pole and E pole are connected to GND; the MOS tubes M1 and M2 form a current mirror, and the MOS tubes M1 and M3 also form a current mirror; the S pole of the MOS tube M3 is connected to the C pole of the transistor Q3, and the current is not affected by VCC.

[0068] In the embodiment of the present invention, the resistor R11 and the resistor R 2a , resistor 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] Where: K is the Boltzmann constant, which is 1.380×10 -23 J / K; N is the ratio of the emitter areas of transistors Q1 and Q2; q is the charge of the electron, which is 1.602×10 -19 C; Vg0 is the potential difference between the bottom of the conduction band and the top of the valence band of silicon at temperature T = 0K; V BE(Tr) is the voltage at temperature Tr; Tr is the reference temperature; η is a constant related to the process.

[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 current flowing through the resistor R 3a , R 3b Nonlinear term I in current NL , thus obtaining a reference current with zero temperature coefficient. The specific working principle is as follows:

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

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

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

[0076] Since the resistor R 2a and R 2b The resistance value is the same, point X (R 2a , Q1, M1, op amp connection node) and Y point (op amp, R11, M2, R 2b , R 3a The voltage at the connection node is equal, then the current flows through the resistor R 2a and R 2b The current flowing through transistor Q1 is the same as the current flowing through transistor Q2. It can be seen from equation (6) that they are both P TAT The base-emitter voltage V BE1 for:

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

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

[0079] Then the resistor R 2a The current I2 generated on is:

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

[0081] Because of the replication effect of the current mirror composed of MOS tubes 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), we can get 3a The current I NL for:

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

[0085] Combining equations (6), (8) and (10), we can obtain the reference current I with zero temperature coefficient: 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 formula (11), as long as equations (5-1) and (5-2) are satisfied, the setting resistors R11 and R 2a , resistor R 3a The resistance value at that time is set, and the reference current source circuit outputs a reference current with a zero temperature coefficient that is independent of temperature. Since the output is a reference current with a zero temperature coefficient that is independent of temperature, the detection result of the temperature detection circuit can be more accurate, preventing the hysteresis comparator from malfunctioning due to the influence of inaccurate temperature; at the same time, the reference current with a zero temperature coefficient is used to power the hysteresis comparator, which can improve the accuracy of the temperature sampling of the hysteresis comparator.

[0088] In the present 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 make the reference current output by the reference current source module pass through the temperature characteristic resistor R(T) to output a voltage signal corresponding to the temperature.

[0089] In the embodiment of the present invention, 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 REFAnd a Poly resistor with temperature characteristics. Constant current I REF Provided by the reference current source circuit and the current correction circuit, when the current I output by the reference current source circuit and the current correction circuit REF The voltage V is obtained by flowing through the temperature characteristic Poly resistor, that is, the temperature detection resistor R(T). R , V R It is the voltage corresponding to the real-time temperature when driving the intelligent power module. 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 are usually correlated with the external temperature within a certain temperature range. The temperature coefficient of resistance is generally used to represent the correlation between the resistance value and temperature. The temperature coefficient of resistance α TCR It refers to the relative change of resistance value when the temperature changes by 1°C, and the unit is ppm / °C. Usually, the correlation between resistance and temperature can be expressed as:

[0092] R(T)=R 0 (1+α TCR1 (T-Tr)+α TCR2 (T-Tr) 2 ) (12);

[0093] Where: R 0 is the resistance value at temperature T=Tr, α TCR1 is the first-order temperature coefficient of resistance, α TCR2 is the second-order temperature coefficient of resistance, Tr represents the reference temperature, and both T and Tr represent thermodynamic temperature in K.

[0094] Among the Poly resistors with positive / negative temperature coefficients and the N-Well resistors with positive temperature coefficients, the Poly resistors are resistors made of the Poly layer used as the gate of the MOS tube, and are divided into low-resistance Poly resistors and high-resistance Poly resistors. The temperature coefficient of the Poly resistor can be positive or negative, mainly depending on the impurity ions (such as P+ or N+) injected into it, and a larger temperature coefficient can be obtained by reducing the doping concentration of impurity ions such as P+ / N+. For the high-resistance Poly resistor, it is precisely because of its lower doping concentration that the high-resistance Poly resistor usually has a larger negative temperature coefficient; while the N-Well resistor is a resistor realized by the N-Well in the P substrate process, and usually has a larger square resistance value. It is precisely because the N-Well resistor generally has a very low P+ doping concentration that it has a larger positive temperature coefficient, and like the Poly resistor, a larger positive temperature coefficient can be obtained by reducing the P+ injection concentration. The high-resistance Poly resistor has a negative temperature coefficient of -3050ppm / ℃, and the N-Well resistor has a positive temperature coefficient of 5600ppm / ℃. Therefore, in the integrated circuit process, both Poly resistors and N-Well resistors can be used as temperature sensing devices in temperature sensing circuits to detect temperature.

[0095] The present invention adopts a high-resistance Poly resistor with a negative temperature coefficient as a temperature sampling device in a temperature detection circuit to realize temperature detection.

[0096] Combining the above, we get V R =I REF *R=I REF *R 0 (1+α TCR1 (T-Tr)+α TCR2 (T-Tr) 2 );

[0097] Since the second-order temperature coefficient of resistance α TCR2 Very small, usually a few ppm / ℃, so compared to its first-order temperature coefficient α TCR1 , α TCR2 can be directly ignored, and the final calculation formula for the real-time temperature T of the intelligent power module is as shown in formula (13).

[0098] V R =I REF *R 0 (1+α TCR1 (T-Tr)) (13);

[0099] Where: V R is the voltage generated by the resistor R(T); I REFis the constant current (reference current) output after passing through the reference current source circuit and the current correction circuit; R 0 is the resistance value at temperature T=Tr, Tr is the reference temperature; α TCR1 is the first-order temperature coefficient of resistance.

[0100] In the present invention, the resistance value of any one of the resistor R1 or the 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] Where: 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 voltages of the high and low levels output by the hysteresis comparator.

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

[0105] When the input voltage Vot starts to be higher than the turn-on threshold, the hysteresis comparator outputs a low-level VOL=0V temperature protection signal, shutting down the HVIC output; when the input voltage Vot starts to be lower than the shut-off threshold, the hysteresis comparator outputs a high-level VOH=5V temperature protection signal, restoring the HVIC output. The turn-on threshold and the shut-off threshold are set according to the voltage value corresponding to the maximum temperature allowed when the intelligent power module is running.

[0106] According to the set turn-on threshold and turn-off threshold, as well as the resistance value of resistor R1 or Rf, by substituting them into formula (1) or (2), the resistance value of another resistor R1 or Rf can be calculated, and the circuit configuration is performed according to the calculated resistance value.

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

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

[0109] Where: I REF is the reference current.

[0110] In the embodiment of the present invention, the reference current required by the hysteresis comparator output by the reference current source circuit when running can be calculated according to formula (3).

[0111] In the present 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] Where: VOH and VOL are the high and low level voltages output by the hysteresis comparator.

[0114] In the embodiment of the present invention, when the input voltage reaches the set threshold voltage, the comparator output signal will flip, but any slight change near the threshold voltage will cause a jump in the output voltage, so although the comparator is relatively sensitive, it has poor anti-interference ability. The hysteresis comparator has a hysteresis characteristic, and when the voltage rises to a certain level, that is, the set threshold, it will flip, that is, it has a certain inertia, and thus has a certain anti-interference ability.

[0115] In the present invention, an intelligent power module with a temperature protection circuit is also proposed, including the temperature protection circuit based on the hysteresis comparator as mentioned above, specifically including: a high-voltage integrated circuit HVIC; wherein the HVIC includes: a high-side and a low-side drive circuit and its corresponding input stage circuit, a dead zone generation circuit, a pulse generation circuit, a level shift circuit, an output circuit, a low-side delay circuit, an undervoltage protection circuit, a current protection ITRIP circuit and a fault logic protection circuit; the temperature protection circuit is connected to the fault logic control circuit, the undervoltage protection circuit, the input stage circuit corresponding to the high-side drive circuit, the dead zone generation circuit and the pulse generation circuit.

[0116] In the embodiment of the present invention, Figure 4 As shown, the temperature protection circuit channel based on the hysteresis comparator drives the HVIC, that is, Figure 5 The 0101 in the circuit includes three channels HIN1, HIN2, and HIN3 for high-side driving circuits and three channels LIN1, LIN2, and LIN3 for low-side driving circuits.

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

[0118] The LIN1, LIN2, and LIN3 input drive signals pass through the input stage circuit, the dead zone generation circuit, and the output OUT_L pulse signal; pass through the low-side delay circuit to achieve consistency between the high-side and low-side drive signals; and output the low-side drive pulse signals LHO and LLO through the output circuit.

[0119] Vot is the output signal of the temperature detection circuit that drives HVIC. This signal reflects the temperature condition of the driving HVIC at all times. The application system can design reasonable temperature protection for the system based on Vot.

[0120] The drive signal HO and LO outputs 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 through the G ports of the gallium nitride field effect transistors 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 to lead out the 1st pin VCC of the (action) module; the S pole of GaNFET1, the D pole of GaN FET2, the U, VS1 of the 6-channel driver HVIC 0101, one end of the bootstrap capacitor C1 and the anode of the bootstrap clamping diode ZD1 are connected together to lead out the 6th pin U, VS1 of the module; the S pole of GaN FET3, the D pole of GaN FET4, the 6-channel driver HVIC 0101's V, VS2, one end of the bootstrap capacitor C2 is connected to the anode of the bootstrap clamping diode ZD2, and is led out as the 8th pin V, VS2 of the module; the S pole of GaN FET5, the D pole of GaN FET6, the W, VS3 of the 6-channel driver HVIC0101 and one end of the bootstrap capacitor C3 are connected to the anode of the bootstrap clamping diode ZD3, and are led out as the 10th pin W, VS3 of the module; the S pole of GaN FET2 is led out as the 2nd pin U- of the module; the S pole of GaN FET4 is led out as the 3rd pin V- of the module; the S pole of GaN FET6 is led out as the 4th pin W- of the module; the VB1 of the 6-channel driver HVIC 0101, the other end of the bootstrap capacitor C1 is connected to the cathode of the bootstrap clamping diode ZD1, and is led out as the 5th pin VB1 of the module; the 6-channel driver HVIC 0101's VB2 and the other end of the bootstrap capacitor C2 are connected to the cathode of the bootstrap clamping diode ZD2, and are brought out as the module's 7th pin VB2; the 6-channel driver HVIC 0101's VB3 and the other end of the bootstrap capacitor C3 are connected to the cathode of the bootstrap clamping diode ZD3, and are brought out as the module's 9th pin VB3; the 6-channel driver HVIC 0101's HIN1 is brought out as the module's 11th pin HIN1 port; the 6-channel driver HVIC 0101's HIN2 is brought out as the module's 12th pin HIN2 port; the 6-channel driver HVIC0101's HIN3 is brought out as the module's 13th pin HIN3 port; the 6-channel driver HVIC 0101's LIN1 is brought out as the module's 14th pin LIN1 port; the 6-channel driver HVIC 0101's LIN2 is brought out as the module's 15th pin LIN2 port; the 6-channel driver HVIC The LIN3 lead of 0101 is used as the 16th pin LIN3 port of the module; the Vot lead of 6-channel driver HVIC 0101 is used as the 21st pin Vot port of the module;The ITRIP of the 6-channel driver HVIC 0101 is connected to one end of the filter capacitor C4, and is led out as the 18th pin ITRIP port of the IPM. The other end of the filter capacitor C4 is connected to VSS; the filter capacitor C5 is connected between VDD and VSS; VDD is led out as the 19th pin VDD port of the IPM; VSS is led out as the 20th pin VSS port of the IPM. ;

[0122] In the present invention, it also includes: a circuit aluminum substrate; an insulating layer is arranged on the surface of the circuit aluminum substrate, and circuit wiring is arranged on the insulating layer; the bottom surface of the circuit aluminum substrate has a texture; the temperature protection circuit, the high-side and low-side drive circuits and their corresponding input stage circuits, the dead zone generation circuit, the pulse generation circuit, the level shift circuit, the output circuit, the low-side delay circuit, the undervoltage protection circuit, the current protection ITRIP circuit and the fault logic protection circuit are fixed on the circuit wiring.

[0123] In the embodiment of the present invention, Figure 7 The figure shows a cross-sectional view of an intelligent power module including an integrated temperature protection circuit HVIC based on a hysteresis comparator. The module comprises: a circuit aluminum substrate 23; a circuit wiring 25 formed on an insulating layer 24 on the surface of the circuit aluminum substrate 23; and the overall circuit wiring is as shown in FIG. Figure 1-4 shown.

[0124] The bottom surface of the circuit aluminum substrate 23 has an uneven texture 26; a circuit element 27 fixed on the circuit wiring 25; a metal wire 28 connecting the circuit element 27 and the circuit wiring 25; a pin 29 connected to the circuit wiring 25, the rest of which is covered by a plating layer; and the entire intelligent power module 22 is sealed by a sealing resin 31.

[0125] The manufacturing method of the intelligent power module 22 is as follows: forming an aluminum material into a suitable size as a circuit substrate 23, and forming a texture 26 on the back thereof by laser etching, polishing, etc., providing an insulating layer 24 on the surface of the circuit substrate 23, and forming a copper foil on the insulating layer 24, and etching the copper foil to form a circuit wiring 25; applying solder paste at a specific position of the circuit wiring 25. Forming the copper material into a suitable shape and performing surface plating treatment as a pin 29, such as Figure 8As shown, in order to prevent the circuit element 27 from being damaged by static electricity in subsequent processing steps, specific positions of the pins 29 are connected by reinforcing ribs 33. The circuit element 27 and the pins 29 are placed on the solder paste; the circuit element 27 and the pins 29 are fixed to the circuit wiring 25 by solidifying the solder paste. The flux remaining on the circuit substrate 23 is removed by spraying, ultrasonic cleaning or other cleaning methods. A connection is formed between the circuit element 27 and the circuit wiring 25 through bonding wires. If the circuit substrate 23 needs to be connected to the ground potential, it also includes a process of transferring the insulating layer 24 through a transfer hole and forming a connection between the ground potential of the circuit wiring 25 and the circuit substrate 23 through bonding wires. The above hardware is sealed by injection molding using a thermoplastic resin or transfer molding using a thermosetting resin, such as Figure 6 As shown. The reinforcing rib 33 of the pin 29 is cut off and formed into a desired shape. The necessary tests are carried out on the intelligent power module, and those that pass the test become intelligent power modules with temperature protection circuits based on hysteresis comparators.

[0126] At the same time, the intelligent power module of the present invention adopts the third-generation semiconductor device GaN FET as its switch device. GaNFET is a third-generation semiconductor, and its built-in FRD (freewheeling diode chip) does not need to be reversed and paralleled with the IGBT made of Si material. Compared with the IGBT and MOSFET made of silicon material, the third-generation semiconductor GaN FET has the advantages of more outstanding breakdown ability, higher electron density and electron mobility, and higher operating temperature. It can bring low loss and high switching frequency: low loss can reduce the heat caused by the resistance, which helps to reduce the volume of the application module. At the same time, GaN FET has a smaller Qg, which can easily increase the frequency and reduce the driving loss. Compared with the IGBT made of silicon material, because the crystal of gallium nitride has stronger chemical bonds, it can withstand electric fields many times higher than silicon devices without collapse. This means that we can shorten the distance between the electrical terminals of the transistor by ten times. This can achieve lower resistance loss and shorter conversion time for electrons. In general, gallium nitride devices have the advantages of fast switching, power loss and low cost. It is very suitable for high-performance integrated power modules.

[0127] It can be understood that the above-mentioned various embodiments mentioned in the present invention can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present invention will not go into details.

[0128] Those skilled in the art will appreciate that, in the above method of specific implementation, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of the steps should be determined by their functions and possible internal logic.

[0129] Once an abnormal situation occurs during the operation of the intelligent power module, it may cause its internal temperature to rise sharply. If the temperature detection is inaccurate at this time, that is, the output value of the temperature detection module is significantly different from the actual value, the microcontroller that receives the temperature signal at the front end of the system will cause a series of erroneous operations, reducing the system's working efficiency; if the protection circuit cannot 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] The present invention designs a temperature protection circuit and an intelligent power module based on a hysteresis comparator. The high-precision temperature detection circuit mainly provides a constant current Iref from a reference source with a low temperature drift coefficient, thereby improving the accuracy of the temperature detection circuit detecting the temperature and the accuracy of the hysteresis comparator sampling; the temperature detection resistor collects accurate real-time temperature, converts it into a voltage input, and compares it with the temperature protection threshold value based on the temperature protection circuit of the hysteresis comparator; the temperature protection circuit uses the hysteresis characteristic of the hysteresis comparator for temperature protection; when the internal temperature of the intelligent power module is higher than the temperature corresponding to the turn-on threshold VotH, the temperature protection circuit of the hysteresis comparator 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 is reduced to the temperature corresponding to the turn-off threshold VotL, the temperature protection circuit of the hysteresis comparator outputs a temperature protection signal to restore the module output, allowing the module and its application system to resume normal operation. The temperature protection circuit based on the hysteresis comparator of the present invention can protect the integrated intelligent power module and its application system from damage caused by high temperature, thereby improving the reliability and market competitiveness of the intelligent power module.

[0131] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill 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 the resistor R1; One end of the resistor R1 and the positive input end of the hysteresis comparator are connected to one end of the resistor Rf, and the other end of the resistor Rf is connected to the positive output end 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, and the hysteresis comparator is used to control the high-voltage integrated circuit to be disconnected or connected to the power supply by internal opening or closing when the voltage signal exceeds or falls below a set threshold voltage; The reference current source module is connected to the resistor R2, and is used to provide a reference current that is independent of temperature for the hysteresis comparator and the temperature detection circuit.

2. The temperature protection circuit based on hysteresis comparator according to claim 1, characterized in that: The reference current source module comprises: a reference current source circuit and a current correction circuit; The current correction circuit includes: a resistor R 3a , resistor R 3b , MOS tube M3 and transistor Q3; The resistor R 3a and resistor R 3b One end is connected to the reference current source circuit operational amplifier OP, and the other end is connected to the MOS tube M3; The current correction circuit MOS tube M3 is respectively connected to the reference current source circuit VCC power supply and the reference current source circuit MOS tube M2; The current correction circuit transistor Q3 is connected to the resistor R 3a and resistor R 3b The other end and MOS tube 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 a zero temperature coefficient; The temperature detection circuit is connected to the reference current source circuit.

3. The temperature protection circuit based on hysteresis comparator according to claim 2, characterized in that: The reference current source circuit includes: MOS tubes M1, M2, operational amplifier OP, resistor R 2a , R 2b , R11 and transistor group Q1, Q2; The D pole of the MOS tube M1 and the D pole of the MOS tube M2 of the reference current source circuit are connected to the power supply VCC, and the G pole of the MOS tube M1 and the G pole of the MOS tube M2 are connected to the output end of the operational amplifier OP; The S pole of the MOS tube M1 of the reference current source circuit, the negative input terminal of the operational amplifier OP, the resistor R 2a One end is connected to the C pole of transistor Q1; The S pole of the MOS tube M2 of the reference current source circuit, the positive input terminal of the operational amplifier OP, the resistor R 2b One end of is connected to one end of resistor R11; The reference current source circuit has the B pole, E pole of transistors Q1 and Q2, and resistor R 2a The other end of the resistor R 2b Connect the other end to GND.

4. The temperature protection circuit based on hysteresis comparator according to claim 1, characterized in that: The temperature detection circuit comprises: a temperature characteristic resistor; The temperature characteristic resistor is connected to the reference current source module, and the temperature characteristic resistor is used to make the reference current output by the reference current source module output a voltage signal corresponding to the temperature after passing through the temperature characteristic resistor.

5. The temperature protection circuit based on hysteresis comparator according to claim 1, characterized in that: The resistance value of any one of the resistor R1 or the resistor Rf is set, and 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); Where: 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 voltages of the high and low levels output by the hysteresis comparator.

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

7. The temperature protection circuit based on hysteresis comparator according to claim 1, 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); Where: VOH and VOL are the high and low level voltages output by the hysteresis comparator.

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

9. An intelligent power module with a temperature protection circuit, comprising the temperature protection circuit based on a hysteresis comparator according to any one of claims 1 to 8, characterized in that: Specifically include: High voltage integrated circuit HVIC; Wherein, the HVIC includes: high-side and low-side driving circuits and their corresponding input stage circuits, dead zone generating circuits, pulse generating circuits, level shifting circuits, output circuits, low-side delay circuits, undervoltage protection circuits, current protection ITRIP 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 circuit corresponding to the high-side drive circuit, the dead zone generation circuit and the pulse generation circuit.

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

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