JP6298188B2 - Temperature detection device - Google Patents

Description

  The present invention relates to a temperature detection device, and more particularly to a temperature detection device for a switching element constituting an inverter device.

  The electric motor is used as a power source for a hybrid vehicle or an electric vehicle combined with an engine. When driving the electric motor, an inverter is used to obtain a predetermined torque and frequency. Inverters are incorporated in automobiles, and miniaturization and high power are desired for securing boarding space.

  The operating temperature of the inverter varies greatly depending on the driving environment of the automobile. In particular, in an automobile equipped with an inverter in the engine room, the inverter becomes hot due to the heat generated by the engine. The switching element in the inverter rises in temperature due to the steady loss caused by current flowing in the switching element itself and the switching loss caused by on / off in addition to the ambient temperature. There is a fear.

  The technique regarding suppression of a temperature rise is already disclosed (for example, refer patent documents 1-3).

JP 2011-7580 A JP-A-5-137255 JP 2010-199490 A

  As shown in Patent Document 1, a photocoupler includes a light emitting diode on the transmission side and a photodiode on the reception side. Since the light emitting diode is arranged on the temperature detection circuit side on the high voltage side and the photodiode is arranged on the low voltage substrate side, the operating voltage of the light emitting diode and the operating voltage of the photodiode are different, and the common substrate It was difficult to make the same package.

  In the technique disclosed in Patent Document 2, the circuit that generates an analog triangular wave is also affected by temperature changes in the external environment, power supply voltage fluctuations, and the like, and cannot generate a stable analog triangular waveform. There has been a problem that the accuracy of the duty cycle of the output pulse signal output from cannot be increased.

  In the prior art disclosed in Patent Document 3, the inverter circuit and the temperature detection diode are mounted on the same substrate to form a chip, and the temperature during operation of the IGBT of the inverter circuit is detected. Since the temperature detection circuit is a separate chip, there is a problem that the detection accuracy is lowered due to the influence of variations in semiconductor elements. Further, in the conventional chip formation using a silicon semiconductor, since the use limit temperature (junction temperature) is 150 ° C., there is a disadvantage that the temperature detection diode and the temperature detection circuit cannot be formed into one chip.

  An object of the present invention is to provide a temperature detection device that allows a temperature detection circuit and an insulating element to be formed on the same frame, and facilitates downsizing of the entire device.

  According to one aspect of the present invention for achieving the above object, a temperature detection circuit that outputs a first pulse signal corresponding to a temperature detected by a temperature sensor, and a temperature detection circuit provided between the temperature detection circuit and the integrated circuit are provided. And an insulating transformer that transmits the first pulse signal to an integrated circuit that operates at an operating voltage different from that of the temperature detecting circuit, and the temperature detecting circuit and the insulating transformer have a quadrangular shape and have a chip shape. Are arranged on the same frame so that one side of each chip faces, and a recess is provided in a boundary region of the frame between the chip of the insulating transformer and the chip of the temperature detection circuit. A temperature sensing device is provided.

  According to the present invention, it is possible to provide a temperature detection device that allows the temperature detection circuit and the insulating element to be formed on the same frame, and facilitates downsizing of the entire device.

The figure which shows the circuit structure of the insulation signal transmission circuit used for the temperature detection apparatus which concerns on 1st Embodiment. The figure which shows the circuit structure of the temperature detection apparatus which concerns on 1st Embodiment. The figure which shows the laminated structure example of the insulation transformer arrange | positioned at the temperature detection apparatus which concerns on 1st Embodiment. The figure which shows the mounting state of the circuit element of the temperature detection apparatus which concerns on 1st Embodiment. The figure which shows the structural example of the apparatus by which the temperature detection apparatus which concerns on 1st Embodiment is used. The figure which shows the circuit structural example of the temperature detection circuit which concerns on 1st Embodiment. The figure which shows the circuit structure of the temperature detection circuit which concerns on 2nd Embodiment. The figure which shows the time chart in the digital comparison circuit of the circuit of FIG. The figure which shows the block configuration of the drive system apparatus by which the power semiconductor module which concerns on 3rd Embodiment was used. The figure which shows the circuit structure of the power semiconductor module which concerns on 3rd Embodiment. The figure which shows the circuit structural example of the temperature detection circuit which concerns on 3rd Embodiment.

  Next, embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the embodiments of the present invention include the material, shape, structure, The layout is not specified as follows. Various modifications can be made to the embodiment of the present invention within the scope of the claims.

[First embodiment]
FIG. 1 shows a circuit configuration of an insulation signal transmission circuit portion in a temperature detection device according to a first embodiment of the present invention.

  The temperature detection device according to the first embodiment is provided between a temperature detection circuit 76 that outputs a first pulse signal corresponding to the temperature detected by the temperature sensor 35, and between the temperature detection circuit 76 and the integrated circuit. And insulation transformers 70 and 71 for transmitting the first pulse signal to an integrated circuit operating at an operating voltage different from that of the temperature detection circuit 76. The temperature detection circuit 76 and the insulation transformers 70 and 71 are provided on a common substrate. Has been implemented.

  In addition, the insulating transformers 70 and 71 are each composed of a primary coil through which a current flows based on a first pulse signal from the temperature detection circuit 76 side and a secondary coil that generates a current to be transmitted to the integrated circuit side. It can be formed up and down across the layer.

  The temperature detection circuit 76 outputs a second pulse signal when the temperature detected by the temperature sensor 35 reaches a predetermined limit value, and the isolation transformers 70 and 71 detect the second pulse signal as a temperature. The circuit 76 is configured to transmit to the integrated circuit.

  In addition, the pulse generators 4 and 5 for shaping the high-level pulse width and the low-level pulse width of the first pulse signal or the second pulse signal so as to be smaller than that of the pulse signal are provided as the isolation transformer 70, 71 is provided in front of the primary side coil.

  Also, a signal demodulating circuit for demodulating the pulse signal whose waveform has been shaped by the pulse generators 4 and 5 to the original pulse width after the secondary coil of the insulating transformers 70 and 71 for generating a current transmitted to the integrated circuit side. Can be configured.

  The insulation signal transmission circuit includes a primary side circuit 80 and a secondary side circuit 81.

  The insulation signal transmission circuit not only insulates the primary side circuit 80 and the secondary side circuit 81, but also transmits a signal from the primary side circuit 80 to the secondary side circuit 81, and conversely, the secondary side circuit Since a signal is transmitted from 81 to the primary side circuit 80, a circuit for controlling the signal transmission is included. In an actual apparatus, for example, the primary side circuit 80 is used as a high voltage side circuit, and the secondary side circuit 81 is used as a low voltage side circuit.

  Further, the primary side circuit 80 and the secondary side circuit 81 have symmetrical circuit configurations, and 80 may be a high voltage side circuit and 81 may be a low voltage side circuit.

  The primary circuit 80 includes a UVLO (low voltage malfunction prevention) circuit 1, inverters 2, 3, 6, 7, pulse generators 4, 5, an RS flip-flop 8, a buffer 9, and a resistor 10.

  The inverter 2 and the resistor 10 also serve as a buffer. The UVLO (low voltage malfunction prevention) circuit 1 monitors the power supply voltage VCC1, and when the power supply voltage VCC1 becomes lower than a predetermined voltage, the pulse generators 4 and 5 and the RS flip-flop 8 are stopped. Stops the I / O signal and locks out the operation. When the power supply voltage VCC1 returns to a normal voltage value, UVLO is canceled and normal operation is started.

  Insulating transformers 31 and 32 are provided so as to connect the primary side circuit 80 and the secondary side circuit 81. The insulating transformer 31 includes an inductor 31a and an inductor 31b insulated from the inductor 31a. The insulating transformer 32 includes an inductor 32a and an inductor 32b insulated from the inductor 32a.

  The isolation transformer 31 transmits the signal of the primary side circuit 80 to the secondary side circuit 81 while insulating the primary side circuit 80 and the secondary side circuit 81. Similarly, the isolation transformer 32 transmits the signal of the secondary side circuit 81 to the primary side circuit 80 while insulating the primary side circuit 80 and the secondary side circuit 81.

  On the other hand, the secondary circuit 81 includes a UVLO (low voltage malfunction prevention) circuit 11, inverters 12 and 13, pulse generators 14 and 15, inverters 16 and 17, RS flip-flop 18, buffer 19, and resistor 20. .

  The inverter 12 and the resistor 20 also serve as a buffer. The UVLO (low-voltage malfunction prevention) circuit 11 monitors the power supply voltage VCC2, and its operation is the same as that of the UVLO circuit 1, so that the description thereof is omitted.

  If the square wave pulse signal input to the terminal IN1 of the primary side circuit 80 is transmitted to the secondary side circuit 81 through the insulating transformer 31 as it is, a current corresponding to the time of the pulse width of the pulse signal is generated. Since the current flows through the insulating transformer 31, the power consumption increases if the pulse width is long. In order to prevent this, the pulse generators 4 and 5 shape and output the pulse width of the input pulse signal to be narrow. Since the pulse signal is formed by alternately forming a high level pulse and a low level pulse, the pulse generator 4 for narrowing the width of the high level pulse and the width of the low level pulse are narrowed. The pulse generator 5 is provided.

  Similarly, when a square wave pulse signal input to the terminal IN2 of the secondary side circuit 81 is transmitted as it is to the primary side circuit 80 via the insulation transformer 32, the pulse width of the pulse signal is changed according to the time. Therefore, if the pulse width is long, the power consumption increases. In order to prevent this, the pulse generators 14 and 15 shape and output the pulse width of the input pulse signal to be narrow. A pulse generator 14 for narrowing the width of the high level pulse and a pulse generator 15 for narrowing the width of the low level pulse are provided.

  Here, the pulse generators 4, 5, 14, and 15 generate a pulse having a narrower width than the original signal by using the rising edge of the pulse signal as a trigger, and can all have the same circuit configuration. The primary side circuit 80 is grounded at GND1, and the secondary side circuit 81 is grounded at GND2. The common ground line is not because the ground potential of the primary side circuit 80 and the ground potential of the secondary side circuit 81 are different.

  Next, the operation of the insulation signal transmission circuit will be described. The pulse signal input to the terminal IN1 of the primary side circuit 80 is inverted by the inverter 2. The inverted signal is input to the pulse generator 5, and a pulse having a narrower width than the original pulse signal is generated using the rising edge of the inverted signal as a trigger, and is output to the primary side of the isolation transformer 31. A change in current due to the pulse supplied to the primary inductor 31a of the insulation transformer 31 generates a current in the secondary inductor 31b of the insulation transformer 31, which is supplied to the RS flip-flop 18 via the inverters 16 and 17. Is done.

  The direction of the current flowing through the secondary inductor 31b determines whether a high level signal is input to the S terminal of the RS flip-flop 18 or a high level signal is input to the R terminal. In the above case, a high level signal is input to the R terminal of the RS flip-flop 18, a low level signal is input to the S terminal, and the output Q is a low level signal. The low level signal from the output Q is output to OUT1 through the buffer 19.

  Since the pulse supplied to the primary inductor 31a of the isolation transformer 31 is based on the inverted signal of the pulse signal input to the IN1 terminal, at the falling edge of the pulse signal input to the IN1 terminal. This is a correspondingly generated pulse. The isolation transformer 31 is operated based on the low level pulse of the pulse signal input to the IN1 terminal, and the low level pulse is generated by the RS flip-flop 18, which is input to the IN1 terminal. That is, the low level pulse portion of the pulse signal is demodulated.

  On the other hand, the inverted signal inverted by the inverter 2 is further inverted by the inverter 3 to return to the original state, that is, the state of the pulse signal input to the terminal of IN1. Using the rise of this pulse signal as a trigger, the pulse generator 4 generates a pulse having a narrower pulse width than the original signal and outputs it to the primary side of the isolation transformer 31. A change in current due to the pulse supplied to the primary inductor 31a of the insulation transformer 31 generates a current in the secondary inductor 31b of the insulation transformer 31, which is supplied to the RS flip-flop 18 via the inverters 16 and 17. Is done.

  In this case, since the direction of the current flowing through the primary inductor 31a is reversed from that when the pulse is generated by the pulse generator 4, the direction of the current flowing through the secondary inductor 31b is also reversed. A high level signal is input to the S terminal of the group 18, a low level signal is input to the R terminal, and the output Q becomes a high level signal. The high level signal from the output Q is output to OUT1 through the buffer 19.

  In the above description, the isolation transformer 31 is operated based on the high level pulse of the pulse signal input to the IN1 terminal, and the high level pulse is generated by the RS flip-flop 18. This is because the IN1 terminal The high-level pulse portion of the pulse signal input to is demodulated.

  As described above, by using the pulse generators 4 and 5, the RS flip-flop 18, and the like, the pulse signal input to the primary side circuit 80 is secondarily reduced while suppressing power consumption for driving the insulating transformer 31. The side circuit 81 can demodulate.

  On the other hand, the operation in which the pulse signal input to IN2 of the secondary side circuit 81 is transmitted to OUT2 of the primary side circuit 80 via the pulse generators 14 and 15 and the RS flip-flop 8 is input to the above-described IN1. Since this is the same as the operation for transmitting the pulse signal, the description is omitted.

  Next, an example of the temperature detection circuit configuration is shown in FIG. First, the external temperature sensor 35 has a configuration in which two diodes are connected in series. The temperature sensor 35 is provided in the vicinity of a switching element such as a power transistor. When the temperature sensor 35 is formed of a diode as in this embodiment, the diode as the temperature sensor has a characteristic that the forward voltage decreases as the temperature rises under constant current conditions. The temperature of a switching element such as a power transistor can be measured by supplying a constant current to the diode and measuring the forward voltage.

  As described above, since it is necessary to flow a constant current through the diode of the temperature sensor 35, the constant current source is constituted by an amplifier 41 using an operational amplifier, an FET 42, and a current mirror circuit 43. The current mirror circuit 43 includes P-type MOS FETs 43a and 43b. The gate of the FET 43a and the gate of the FET 43b are connected, and the drain of the FET 43a and the drain of the FET 43b are connected. The FET 43b is diode-connected.

  When the current flowing between the drain and source of the FET 43b is determined, the current flowing between the drain and source of the FET 43a is also determined. The amplifier 41 and the N-type MOS FET 42 constitute a power amplifier.

  Next, the temperature detection voltage TAIN detected by the temperature sensor 35 is input to the AD conversion circuit 44. The AD conversion circuit 44 is configured by a so-called successive approximation AD conversion circuit or the like. The TAIN signal converted into a digital value by the AD conversion circuit 44 is input to the digital comparison circuit 45.

  The digital comparison circuit 45 includes a counter, a digital comparator, and the like. The oscillation circuit 46 generates a clock pulse of a predetermined frequency, and a digital triangular wave signal is generated by counting the clock from the oscillation circuit 46 with a counter in the digital comparison circuit 45. The digital comparison circuit 45 includes a digital comparator, and compares the digital triangular wave signal with the TAIN signal converted into a digital value. When the digital TAIN signal is larger than the digital triangular wave signal, a high level signal is output. When the digital TAIN signal is smaller than the digital triangular wave signal, a low level signal is output.

  The output signal of the digital comparison circuit 45 is then output to the inverter circuit. The inverter circuit includes an N-type MOS FET 37 and a P-type MOS FET 36. The source of the FET 36 and the drain of the FET 37 are connected, and the gate of the FET 36 and the gate of the FET 37 are connected. The output signal of the digital comparison circuit 45 is input to the gate of the FET 36 and the gate of the FET 37.

  The output signal of the digital comparison circuit 45 is inverted by an inverter formed of FETs 36 and 37 and output as a TOUT signal. The signal at the VTO terminal indicates the high level value of the TOUT signal. Thus, the magnitude of the temperature from the temperature sensor 35 is detected by the pulse width of the TOUT signal or the duty signal.

  Here, the FAL signal also present at the connection terminal will be described. This indicates that the temperature detected by the temperature sensor 35 is very high and the temperature detection voltage signal TAIN is extremely low. Thus, this signal is generated when the temperature detected by the temperature sensor 35 reaches the limit value.

  A DC power source is connected to the negative terminal of the comparator 49. The voltage value of the DC power source is set to a voltage corresponding to the temperature limit value. On the other hand, the temperature detection voltage signal TAIN is input to the plus terminal of the comparator 49. When the temperature detection voltage signal TAIN is higher than the voltage value of the DC power supply, a high level signal is output from the comparator 49. The high level signal from the comparator 49 is input to the gate of the N-type MOS FET 38. As a result, the FET 38 is turned on, and the FAL terminal is in a low level state.

  On the other hand, when the detected temperature decreases and the temperature detection voltage signal TAIN becomes lower than the voltage value of the DC power supply, the output of the comparator 49 is inverted to a low level signal. The low level signal from the comparator 49 is input to the gate of the N-type MOS FET 38. As a result, the FET 38 is turned off, and the FAL terminal is in a high level state. In this way, it is notified that the temperature rise of the temperature detection target has reached the limit. This FAL signal is taken into an external control device or the like and used as a control signal for stopping the operation of the temperature detection target.

  The temperature detection device 90 of FIG. 2 is configured by combining the insulation signal transmission circuit of FIG. 1 and the temperature detection circuit of FIG. 6 are the same as those of the circuit of FIG. 6, and therefore the description of the temperature detection circuit which is a high voltage side circuit is omitted.

  In FIG. 2, unlike the insulation signal transmission circuit of FIG. 1, bidirectional signal transmission is not performed between the primary side circuit and the secondary side circuit separated by the insulation transformer circuit 101. This is a temperature detection device in which a signal is transmitted in one direction from the 100 side to the signal demodulation circuit 102 side.

  Therefore, in order to suppress the power consumption of the isolation transformers 70 and 71 described with reference to FIG. 1, a pulse generator for shaping and outputting the pulse width of the input pulse signal is provided only on the temperature detection circuit 100 side. . The signals output from the temperature detection circuit 100 are two systems, that is, a TOUT signal that is a temperature detection signal and an FAL signal that informs that a limit temperature has been reached. As for the signal transmission path of one system, as described in FIG. 1, there are a pulse generator for narrowing the width of the high level pulse of the input pulse signal and a pulse generator for narrowing the width of the low level pulse. is necessary.

  For this reason, as shown in FIG. 2, a first pulse generator 52 and a second pulse generator for transmitting a pulse signal corresponding to the detected temperature output from the digital comparison circuit 45 are provided. Further, a third pulse generator 54 and a fourth pulse generator 55 are provided for transmitting an FAL signal notifying that the limit temperature output from the comparator 49 has been reached.

  1 and FIG. 2 are as follows. The inverter 2 of FIG. 1 is the inverter 47 of FIG. 2, the inverter 3 is the inverter 48, the pulse generator 4 is the first pulse generator 52, the pulse generator 5 is the second pulse generator 53, and the insulation transformer 31 is The isolation transformer 70 corresponds to the inverter 56, the inverter 17 corresponds to the inverter 57, the RS flip-flop 18 corresponds to the RS flip-flop 60, and the buffer 19 corresponds to the buffer 62.

  Accordingly, since the operation is the same as that described with reference to FIG. 1, the description of the above-described circuit of FIG. 2 and the description of the signal demodulation circuit 102 are also omitted. In addition, an inverter 50, an inverter 51, a third pulse generator 54, a fourth pulse generator 55, an insulating transformer 71, an inverter 58, an inverter 59, RS, which constitute a signal system for transmitting and demodulating the FAL signal output from the comparator 49 Since the flip-flop 61 and the buffer 63 are the same as those described above, this description is also omitted.

  Here, the temperature detection circuit 100 and the isolation transformer circuit 101 are formed on the same substrate (same frame). The insulating transformer circuit 101 does not need to supply a power supply voltage and can obtain a current signal by magnetic mutual induction, and thus can be used as a common substrate with the temperature detection circuit 100.

  FIG. 4 shows a mounting state on a substrate in which the temperature detection device of FIG. 2 is packaged.

  FIG. 4A shows an internal photographic image viewed from the top surface of the package. FIG. 4B is an enlarged photographic image of FIG. 4A, and the middle position corresponds to the insulating transformer circuit 101. Further, the arrangement on the left side corresponds to the temperature detection circuit 100, and the arrangement on the right side corresponds to the signal demodulation circuit 102.

  A plastic mold is formed in a portion S between the insulating transformer and the signal demodulating circuit.

  The insulating transformer is formed as a chip, formed on the same substrate as the temperature detection circuit, and a copper island is formed on the back surface. The structure seen through from the back surface on which the copper island is formed is shown in FIG. A bonding pad is formed on the copper island, and a copper coil is formed inside the copper island.

  FIG. 3 shows a laminated structure of the insulating transformer formed into a chip.

  A silicon (Si) substrate is formed on the copper island, and a primary or secondary copper coil is formed on the silicon substrate.

  A dielectric layer made of SiO2 or the like is laminated so as to cover the copper coil. A secondary-side or primary-side copper coil is formed on the dielectric layer. Thus, the primary side coil and the secondary side coil are electrically insulated by the dielectric layer. FIG. 4C shows a view seen through this from the back side.

  Next, an example of an apparatus to which the temperature detection apparatus according to the present embodiment is applied is shown in FIG. FIG. 5 shows an example in which signals are transmitted bidirectionally between a low-voltage side substrate 410 and a high-voltage side substrate 511 of an automobile. The low voltage side substrate 410 is mainly configured by the ECU 72. The ECU is called an electronic control unit or an engine control unit, and is a unit that performs engine control, drive system control, steering system control, and the like by a computer.

  A power semiconductor module 77 for driving the motor 112 is mounted on the high voltage side substrate 411. As a power switching element of the power semiconductor module 77, an insulated gate bipolar transistor (IGBT) is illustrated. The gate of each IGBT is connected to the gate driver 75.

  A control signal output from the ECU 72 is transmitted to the gate driver 75 via the isolator 73. A drive signal is output from the gate driver 75 in accordance with a control signal from the ECU 72. PWM control is performed by this drive signal, and the six IGBTs of the power semiconductor module 77 are turned on and off at a desired timing, and three-phase AC power for driving the motor 112 is generated.

  On the other hand, the temperature is detected by a temperature sensor (not shown) installed near the IGBT of the power semiconductor module 77, the detection signal is input to the temperature detection circuit 76, converted into a pulse signal and output, and the isolator 74 is output. Is transmitted to the ECU 72. Conventionally, a photocoupler has been used as an isolator. However, in this embodiment, an insulating transformer is used, and the temperature detection device 90 in which the temperature detection circuit 76 and the isolator 74 are packaged is used. The temperature detection device 90 of FIG. 5 is the temperature detection device 90 shown in FIG.

(Comparative example)
As a comparative example, in an in-vehicle system that uses a vehicle body equipped with a power switching element as a reference potential, a low-voltage board and a high-voltage board are connected, and the low-voltage board and the high-voltage board are insulated. On the side, a power card is mounted.

  The power card is packaged with a power switching element and a diode as a temperature sensor.

  Here, a power switching element comprises the inverter connected to the rotary electric machine for vehicle travel. The rotating electric machine for vehicle traveling is a rotating electric machine as an in-vehicle main machine, a generator for charging a high voltage battery that supplies electric power to the rotating electric machine as an in-vehicle main machine, or the like. On the other hand, the temperature sensor is disposed in the vicinity of the power switching element and detects its temperature.

  Further, a temperature detection circuit that converts the temperature detection signal into a PWM signal is mounted on the high voltage substrate side. The low voltage substrate and the high voltage substrate are insulated by a photocoupler, and are insulating means for transmitting a signal from one to the other while insulating the low voltage substrate and the high voltage substrate.

  Usually, since a photocoupler is used as an insulating element that insulates a low voltage substrate from a high voltage substrate, the photocoupler and the temperature detection circuit are not arranged on the same substrate but are built in separate packages.

  The photocoupler includes a light emitting diode on the transmission side and a photodiode on the reception side. The light emitting diode is arranged on the temperature detection circuit side on the high voltage side, and the photodiode is arranged on the low voltage substrate side. Thus, the operating voltage of the light emitting diode and the operating voltage of the photodiode are different, and cannot be manufactured on a common substrate, making it difficult to form the same package.

  According to the temperature detection device according to the first embodiment, the temperature detection circuit 100 that outputs the first pulse signal corresponding to the temperature detected by the temperature sensor 35 and the temperature detection circuit 100 that outputs the first pulse signal. Insulating transformers 70 and 71 are formed between the integrated circuit that operates at an operating voltage different from the above, and the first pulse signal is transmitted from the temperature detection circuit 100 to the integrated circuit while maintaining insulation.

  Thus, since the isolation transformers 70 and 71 are used, it is not necessary to supply different voltages to the isolation transformers 70 and 71, and signal transmission is performed by magnetic change. For this reason, the temperature detection circuit 100 and the insulating transformers 70 and 71 can be mounted on a common substrate, and the apparatus can be downsized.

[Second Embodiment]
FIG. 7 shows a circuit configuration of the temperature detection circuit 210 according to the second embodiment of the present invention.

  The temperature detection circuit according to the second embodiment includes an A / D conversion circuit 44 that converts a temperature detection signal from the temperature sensor 35 into a digital value, and a triangular wave generation that outputs a digital signal corresponding to a triangular waveform in time series. Digital comparator (digital comparison circuit) that compares the circuit (first counter 162 and oscillation circuit 163) and the digital temperature detection signal output from the A / D conversion circuit 44 with the digital signal output from the triangular wave generation circuit 45, and a duty signal is output from the digital comparator 45.

  The period in which the comparison process is performed by the digital comparator 45 is composed of four cycles, with one cycle from the maximum value of the triangular waveform to the next maximum value or from the minimum value of the triangular wave to the next minimum value.

  Further, the duty ratio is determined in the first two cycles in one cycle in which the comparison process is performed.

  Further, when the temperature detected by the temperature sensor 35 reaches a limit value, a detection signal can be output from the digital comparator 45.

  Further, the temperature sensor 35 can be provided with an element that operates at a constant current and changes in voltage according to temperature.

  The constant current source for supplying current to the temperature sensor 35 includes a current mirror circuit 301 and is configured to change the current to be supplied to the temperature sensor 35 according to the value of a resistor connected to the current mirror circuit 301.

  Here, as an example, the external temperature sensor 121 has a configuration in which two diodes are connected in series. The temperature sensor 121 is provided in the vicinity of a switching element such as a power transistor.

  When the temperature sensor 121 is formed of a diode as in this embodiment, the diode as the temperature sensor has a characteristic that the forward voltage decreases as the temperature rises under constant current conditions. The temperature of a switching element such as a power transistor can be measured by supplying a constant current to the diode and measuring the forward voltage.

  As described above, since it is necessary to flow a constant current through the diode of the temperature sensor 121, the constant current source includes variable resistors 151 and 152, an amplifier 302 using an operational amplifier, an FET 303, and a current mirror circuit 301.

  The reference voltage generation circuit 105 serves to adjust and supply a necessary voltage to a specific element in the temperature detection circuit 210 from the power supply voltage VCC. For example, the reference voltage generation circuit 105 generates an output voltage of 1.25V. Can be configured. The current mirror circuit 301 is composed of P-type MOS FETs 112 and 113. The gate of the FET 112 and the gate of the FET 113 are connected, and the drain of the FET 112 and the drain of the FET 113 are connected. The FET 113 is diode-connected.

  When the current flowing between the drain and source of the FET 113 is determined, the current flowing between the drain and source of the FET 112 is also determined. The amplifier 302 and the N-type MOS FET 303 constitute a power amplifier. By adjusting the variable resistors 151 and 152, the current flowing through the FET 113 can be changed, and the current flowing through the diode of the temperature sensor 121 can be changed.

  The ratio of the current flowing between the drain and source of the FET 113 and the current flowing between the drain and source of the FET 112 is determined by the ratio of the external resistor 120 connected to the FET 303 and the internal resistance of the temperature sensor 121. is there. For example, since the internal resistance of the temperature sensor 121 is normally set to about 1/20 of the resistance 120, the current mirror circuit 301 generates a current about 20 times the current flowing between the drain and source of the FET 113. Functions as a constant current source to supply to

  On the other hand, the operational amplifier 104 amplifies the voltage generated by the reference voltage generation circuit 105 and supplies the amplified voltage to the AD conversion circuit 107. A variable resistor 141 is provided between the negative input terminal and the output terminal of the amplifier 104. A variable resistor 142 provided between the negative input terminal of the amplifier 104 and GND is connected in series with the variable resistor 141. The variable resistors 141 and 142 adjust the output voltage of the amplifier 104 and supply it to the AD conversion circuit 107. For example, as shown in the figure, it is set to 3.3V.

  Next, a comparison between the temperature detection voltage detected by the temperature sensor 121 and a triangular wave will be described. The AD conversion circuit 107 includes a successive approximation register 171, a DA converter 172, an analog comparator 173, a register 174, and a DA converter 164a. This is a so-called successive approximation type AD converter circuit. The successive approximation register 171 is a register that sequentially generates approximate values sequentially. First, when there is a conversion start command, the successive approximation register 171 sets the MSB to 1. This result is D / A converted by the DA converter 172, returned to an analog amount, and compared with the temperature detection voltage by the comparator 173. Thereby, if the voltage value of the temperature detection voltage is higher, the MSB remains at 1.

  Next, the second bit of the successive approximation register 171 is similarly set to 1. This result is D / A converted by the DA converter 172, returned to an analog amount, and compared with the temperature detection voltage by the comparator 173. If the temperature detection voltage is lower, the second bit of the successive approximation register 171 is returned to zero. In this manner, the bits are sequentially set in the direction from the MSB to the LSB and compared, and the operation is continued when the voltage is larger than the temperature detection voltage and reset when the voltage is smaller. If this operation is continued until LSB, the digital quantity closest to the temperature detection voltage remains. The digital value is extracted and stored in the register 174.

Next, the digital signal of the temperature detection voltage held in the register 174 is output to the digital comparison circuit 200. In the digital comparison circuit 200, all are processed with digital signals.
The digital comparison circuit 200 includes a digital comparator 161, a first counter 162, an oscillation circuit 163, and a second counter 164. The digital value of the register 174 and the output value of the first counter 162 are digitally compared by the digital comparator 161, and a high level signal is output when the digital value of the register 174 is larger. Further, when the digital value of the register 174 is smaller than the output value of the first counter 162, a low level signal is output.

  The oscillation circuit 163 generates a clock signal having a constant period, and the first counter 162 counts the number of clocks. The first counter 162 sequentially outputs a value obtained by counting the clocks from the oscillation circuit 163 to the comparator 161.

  FIG. 8 is a time chart relating to the digital comparison circuit 200, and mainly shows a time chart relating to data compared by the comparator 161 and an output from the comparator 161.

  The clock from the oscillation circuit 163 is also input to the second counter 164. The second counter 164 is used to cancel the offset of the comparator 173, and is set to count up to a digital value corresponding to the offset amount of the comparator 173. When the oscillation circuit 163 operates, the second counter 164 performs counting until the amount corresponding to the offset of the comparator 173 is reached, and outputs the value to the DA converter 175. The input digital value from the second counter 164 is converted into an analog amount by the DA converter 175 and input to the offset adjustment terminal of the comparator 173. Thereby, the offset which the comparator 173 has is canceled.

  The digital value output from the first counter 162 increases in a stepwise manner (for example, by 1) according to the clock from the oscillation circuit 163, which corresponds to the inclined portion S1 of the triangular wave. On the other hand, when the numerical value counted by the first counter 162 reaches the maximum value S3 of the triangular wave, the first counter 162 is set to reset the numerical value counted so far to zero. Therefore, since it immediately shifts to 0 from the maximum value, it becomes a straight line having no inclination as indicated by S3 of the triangular wave, and S3 has no pulse width. Thus, the first counter 162 and the oscillation circuit 163 constitute a triangular wave generating circuit that outputs a digital signal corresponding to an analog triangular waveform in time series.

  The digital value of the temperature detection voltage value supplied from the register 174 to the comparator 161 is indicated by the TAIN signal in FIG. As shown in FIG. 8, the TAIN signal is compared with the count value corresponding to the triangular wave output from the first counter 162. Here, as shown in each of the periods T0 to T4, the period for comparison is composed of two cycles when the DutyHi period and the DutyLo period are one cycle.

  The DutyHi period corresponds to a period from the maximum value of the triangular wave to the next maximum value or a period from the minimum value of the triangular wave to the next minimum value. The DutyLo period is a period following the DutyHi period, and corresponds to a period from the maximum value of the triangular wave to the next maximum value or a period from the minimum value of the triangular wave to the next minimum value.

  8 exemplifies how the level of the TAIN signal changes. Therefore, the result of comparing the TAIN signal described in FIG. 8 with the triangular wave and the TOUT corresponding to the output signal of the comparator 161 are illustrated. It should be noted that the timing does not match.

  Specifically, the process of forming the TOUT signal will be described. For example, as shown in FIG. 8, one period from the maximum value of the triangular wave to the next maximum value or one period from the minimum value of the triangular wave to the next minimum value can be set to 2.5 milliseconds.

  If, in period T1, TAIN is 90% of the maximum value of the triangular wave line N1, the comparator 161 compares the triangular wave with N1, and a high level signal is output for a period when N1 is higher than the triangular wave. A low level signal is output during a period when N1 is lower than the triangular wave. Since it corresponds to 90% of the cycle of 2.5 ms, 2.5 × 0.9 = 2.25 ms. This is the pulse period described as 2.25 msec Duty 90% clamp.

  The next DutyLo period has a pulse width of 2.75 msec, which is a total of 2.5-2.25 = 0.25 msec and 2.5 msec. The period T1 is composed of two DutyHi periods and two DutyLo periods. In the first DutyHi period and DutyLo period, the result of comparison between the triangular wave and N1 by the comparator 161 is output, and the next DutyHi period In the DutyLo period, a high-level pulse having a width of 2.5 msec and a low-level pulse having a width of 2.5 msec are output without performing comparison processing.

  The operation of the cycle T1 described above is similarly performed at T2, T3, and T4. In T2, when TAIN maintains the state of 90% line N1 of the maximum value of the triangular wave, a high-level pulse having a width of 2.25 msec is output in the first DutyHi period, as in the operation in period T1, In the first DutyLo period, a low level pulse having a pulse width of 2.75 ms is output.

  In the next DutyHi period and DutyLo period, a high-level pulse of 2.5 msec width and a low-level pulse of 2.5 msec width, which are periods of a triangular wave, are output without performing comparison processing. This state is shown in FIG.

  In the period T3, the case where TAIN is the 10% line N2 of the maximum value of the triangular wave is described. The comparator 161 compares the triangular wave and N2, and outputs a high level signal during a period when N2 is higher than the triangular wave, and outputs a low level signal during a period when N2 is lower than the triangular wave. Since the first DutyHi period corresponds to 10% of the period of 2.5 milliseconds, 2.5 × 0.1 = 0.25 milliseconds. This is the pulse period described as 0.25 msec Duty 10% clamp.

  The next DutyLo period has a pulse width of 4.75 msec, which is the sum of 2.5−0.25 = 2.25 msec and 2.5 msec. Further, in the next DutyHi period and DutyLo period, a high level pulse of 2.5 msec width and a low level pulse of 2.5 msec width, which are periods of a triangular wave, are output without performing comparison processing.

  In the period T4, TAIN maintains the state of the 10% line N2 having the maximum value of the triangular wave, so that a high level pulse having a width of 0.25 msec is output in the first DutyHi period as in the operation in the period T3. In the first DutyLo period, a low level pulse having a pulse width of 4.75 ms is output. In the next DutyHi period and DutyLo period, a high-level pulse of 2.5 msec width and a low-level pulse of 2.5 msec width, which are periods of a triangular wave, are output without performing comparison processing.

  As described above, for each period Tn (n = 0 to N), the comparator 161 sends the result of comparing the temperature detection voltage signal TAIN of the temperature sensor 121 with the triangular wave to the level shifter 108.

  Here, the FAIL signal also present at the connection terminal will be described. For example, in FIG. 8, as shown in the relationship between the triangular waveform and the TAIN signal in the period T4, the operation is performed when the portion where the TAIN signal is higher than the triangular waveform signal has disappeared. This indicates that the temperature detected by the temperature sensor 121 is very high, and the temperature detection voltage signal TAIN is extremely low.

  In this case, the comparator 161 outputs a low level signal to notify that the temperature rise of the temperature detection target has reached the limit. The low level signal from the comparator 161 is input to the gate of the N-type MOS FET 109. As a result, the FET 109 is turned off, and the FAIL terminal is in a high level state. This FAIL signal is taken into an external control device or the like and used as a control signal for stopping the operation of the temperature detection target.

  The DC voltage level of the output signal of the comparator 161 is converted by the level shifter 108, and the high level signal is converted into a low level signal and the low level signal is converted into a high level signal. The output from the level shifter 108 is input to the gate of the N-type MOS FET 111 and the gate of the P-type MOS FET 110.

  Since the source of the FET 110 and the drain of the FET 111 are connected and the gate of the FET 110 and the gate of the FET 111 are connected, the FET 110 and the FET 111 constitute an inverter. For this reason, the output signal from the level shifter 108 is inverted by the inverters of the FETs 110 and 111. Therefore, in terms of logic, the output signal from the comparator 161 becomes the TOUT signal as it is. Thus, the temperature detected by the temperature sensor 121 is detected after being converted into the pulse width or duty ratio of the pulse signal. Also, the VTO signal shown in FIG. 8 indicates the high level value of the TOUT signal. This TOUT signal is used for controlling torque and switching frequency, for example.

  As described above, in order to obtain a duty signal from the comparator, the temperature detection voltage signal is converted into a digital value, and a triangular wave serving as a reference for comparison is used as a digital signal to perform comparison processing using the digital value. As in the case of an analog triangular wave, the maximum value, the minimum value, the inclination of the triangular wave, etc. of the triangular wave do not fluctuate, and an extremely accurate duty signal can be obtained.

(Comparative example)
As a comparative example, in order to avoid the destruction of the switching element, the temperature of the switching element is detected and the inverter is cooled based on the obtained information, or the temperature of the switching element and the inverter is measured to determine the torque and the switching frequency. There is a technology to limit.

  In this comparative example, the voltage of a PN junction semiconductor element such as a diode changes linearly with respect to a temperature change. By installing a diode as a temperature sensor near the switching element and observing the voltage, temperature information with high accuracy and high response can be obtained. If highly accurate temperature information can be obtained, torque can be output to near the breakdown temperature of the switching element, and higher density of the inverter can be expected.

  As described above, when a PN junction semiconductor element such as a diode is used as a temperature sensor, the temperature detection circuit compares the temperature detection voltage from the temperature sensor with the triangular wave generated by the analog circuit using a comparator. .

  The comparator compares the triangular wave and the temperature detection voltage.For example, when the temperature detection voltage is higher than the triangular wave, the output of the comparator is high.When the temperature detection voltage is lower than the triangular wave, the output of the comparator is low. Configure to be level. As the temperature rises, the temperature detection voltage falls, so the duty cycle of the pulse signal output from the comparator changes. Based on this pulse signal, the torque and switching frequency are controlled to control the temperature. To prevent the rise.

  For example, when power control is performed using a power switch, a duty signal is generated by comparing an analog triangular waveform with a numerical value based on a command value.

  However, since the output pulse signal of the comparator is determined by comparing the triangular wave and the temperature detection voltage, in order to increase the accuracy of the duty cycle of the output pulse signal output from the comparator, the maximum value of the analog triangular wave, It is necessary to accurately generate the minimum value and the inclination of the triangular wave.

  However, the circuit that generates the analog triangular wave is affected by temperature changes in the external environment, fluctuations in the power supply voltage, etc., and cannot generate a stable analog triangular waveform, so the duty of the output pulse signal output from the comparator It is difficult to increase the accuracy of the cycle.

  In the temperature detection circuit according to the second embodiment, an A / D conversion circuit 107 that converts a temperature detection signal from the temperature sensor 121 into a digital value, and a triangular wave generation that outputs a digital signal corresponding to a triangular waveform in time series A circuit (first counter 162, oscillation circuit 163), and a digital comparator 161 that compares the digital temperature detection signal output from the A / D conversion circuit 107 with the digital signal output from the triangular wave generation circuit. The comparator 161 outputs a duty signal. In this way, since not only the temperature detection signal but also the triangular waveform is a digital signal, no fluctuation occurs with respect to the maximum value, the minimum value, the inclination of the triangular waveform, etc. of the triangular waveform. Can be obtained.

[Third embodiment]
FIG. 9 shows a block configuration example of a drive system device including a power semiconductor module according to the third embodiment.

  The power semiconductor module 77 according to the third embodiment includes a power element circuit configured by a power switching element (IGBT), a temperature detection diode 35 that measures the temperature of the power switching element, and a temperature detection diode 35. The temperature detecting circuit 77a for detecting the temperature by the voltage signal is provided, and the temperature detecting diode 35 and the temperature detecting circuit 77a are formed on one chip by the SOI structure.

  Further, the chip and the power element circuit are formed on a common frame and are built in one package.

  FIG. 9 shows an example in which signals are transmitted bidirectionally between a low-voltage side substrate 410 and a high-voltage side substrate 411 of an automobile. The low voltage side substrate 410 is mainly configured by the ECU 72. The ECU is called an electronic control unit or an engine control unit, and is a unit that performs engine control, drive system control, steering system control, and the like by a computer.

  A power semiconductor module 77 having an inverter circuit 77b for driving the motor 112 is mounted on the high voltage side substrate 411. The power semiconductor module 77 is formed in one package, and a temperature detection circuit 77a and an inverter circuit 77b are formed therein. An insulated gate bipolar transistor (IGBT) is illustrated as a power switching element of the inverter circuit 77b. The gate of each IGBT is connected to a gate driver 75, and a flywheel diode is connected in parallel with each IGBT. Each IGBT is supplied with a DC voltage from a DC power supply 78.

  A control signal output from the ECU 72 is transmitted to the gate driver 75 via the isolator 73. A drive signal is output from the gate driver 75 in accordance with a control signal from the ECU 72. PWM control is performed by this drive signal, and the six IGBTs of the inverter circuit 77b are turned on and off at a desired timing, and three-phase AC power for driving the motor 112 is generated.

  On the other hand, the temperature is detected by a diode temperature sensor installed near the IGBT of the inverter circuit 77 b, the detection signal is input to the temperature detection circuit 77 a, converted into a pulse signal, and output, and the ECU 72 passes through the isolator 74. Is transmitted to. For the isolators 73 and 74, a photocoupler or an insulating transformer is used.

  Here, the temperature detection circuit 77a and the temperature sensor 35 using a diode are formed into one chip using an HT-SOI (Silicon on Insulator) structure when a semiconductor laminated structure is manufactured. The SOI structure is a technology in which a thin insulating oxide film is formed on a silicon substrate, and an electric circuit such as a transistor or a sensor is formed on the silicon oxide. Further, the SOI structure is faster and consumes less power than a normal bulk CMOS technology. It is a highly technical technique. The junction temperature in this SOI structure is 225 ° C., and by performing a single chip with the SOI structure, temperature detection can be performed accurately and stably.

  Furthermore, the temperature sensor 35 and the temperature detection circuit 77a that are made into one chip by the SOI structure are built in the same package as the inverter circuit 77b. That is, the chip of the inverter circuit 77b and the chip of the temperature detection circuit 77a including the temperature sensor are arranged on the same frame. In this way, the accuracy of temperature detection is further improved.

  FIG. 10 exemplifies the arrangement position of the temperature sensor 35 composed of a diode in the power semiconductor module 77 of FIG. 9. The temperature sensor 35 is provided near the IGBT. Further, the temperature sensor 35 has a configuration in which two diodes are connected in series. The diode as the temperature sensor has a characteristic that the forward voltage decreases as the temperature increases under constant current conditions. The temperature of a switching element such as a power transistor can be measured by supplying a constant current to the diode and measuring the forward voltage.

  Further, in FIG. 10, the temperature detection circuit 77a and the temperature sensor 35 are illustrated separately from each other, but this is for easy understanding of the arrangement position of the temperature detection diode. The temperature detection circuit 77a is made into one chip by the SOI structure. On the other hand, a control circuit 80 is provided as a circuit for outputting a control signal including the function of the gate driver 75 in FIG.

  Next, FIG. 11 shows a circuit configuration example of the temperature detection circuit 77a shown in FIGS. As described above, since it is necessary to flow a constant current through the diode of the temperature sensor 35, the constant current source includes the amplifier 41 using the operational amplifier, the FET 42, and the current mirror circuit 43. The current mirror circuit 43 includes P-type MOS FETs 43a and 43b. The gate of the FET 43a and the gate of the FET 43b are connected, and the drain of the FET 43a and the drain of the FET 43b are connected. The FET 43b is diode-connected.

  When the current flowing between the drain and source of the FET 43b is determined, the current flowing between the drain and source of the FET 43a is also determined. The amplifier 41 and the N-type MOS FET 42 constitute a power amplifier.

  Next, the temperature detection voltage TAIN detected by the temperature sensor 35 is input to the AD conversion circuit 44. The AD conversion circuit 44 is configured by a so-called successive approximation AD conversion circuit or the like. The TAIN signal converted into a digital value by the AD conversion circuit 44 is input to the digital comparison circuit 45.

  The digital comparison circuit 45 includes a counter, a digital comparator, and the like. The oscillation circuit 46 generates a clock pulse of a predetermined frequency, and a digital triangular wave signal is generated by counting the clock from the oscillation circuit 46 with a counter in the digital comparison circuit 45. The digital comparison circuit 45 includes a digital comparator, and compares the digital triangular wave signal with the TAIN signal converted into a digital value. When the digital TAIN signal is larger than the digital triangular wave signal, a high level signal is output. When the digital TAIN signal is smaller than the digital triangular wave signal, a low level signal is output.

  The output signal of the digital comparison circuit 45 is then output to the inverter circuit. The inverter circuit includes an N-type MOS FET 37 and a P-type MOS FET 36. The source of the FET 36 and the drain of the FET 37 are connected, and the gate of the FET 36 and the gate of the FET 37 are connected. The output signal of the digital comparison circuit 45 is input to the gate of the FET 36 and the gate of the FET 37.

  The output signal of the digital comparison circuit 45 is inverted by an inverter formed of FETs 36 and 37 and output as a TOUT signal. The signal at the VTO terminal indicates the high level value of the TOUT signal. Thus, the magnitude of the temperature from the temperature sensor 35 is detected by the pulse width of the TOUT signal or the duty signal.

  Here, the FAL signal also present at the connection terminal will be described. This indicates that the temperature detected by the temperature sensor 35 is very high and the temperature detection voltage signal TAIN is extremely low. Thus, this signal is generated when the temperature detected by the temperature sensor 35 reaches the limit value.

  A DC power source is connected to the negative terminal of the comparator 49. The voltage value of the DC power source is set to a voltage corresponding to the temperature limit value. On the other hand, the temperature detection voltage signal TAIN is input to the plus terminal of the comparator 49. When the temperature detection voltage signal TAIN is higher than the voltage value of the DC power supply, a high level signal is output from the comparator 49. The high level signal from the comparator 49 is input to the gate of the N-type MOS FET 38. As a result, the FET 38 is turned on, and the FAL terminal is in a low level state.

  On the other hand, when the detected temperature decreases and the temperature detection voltage signal TAIN becomes lower than the voltage value of the DC power supply, the output of the comparator 49 is inverted to a low level signal. The low level signal from the comparator 49 is input to the gate of the N-type MOS FET 38. As a result, the FET 38 is turned off, and the FAL terminal is in a high level state. In this way, it is notified that the temperature rise of the temperature detection target has reached the limit. This FAL signal is taken into an external control device or the like and used as a control signal for stopping the operation of the temperature detection target.

(Comparative example)
As a comparative example, in a system such as a three-phase inverter that drives an electric motor using an IGBT (Insulated Gate Bipolar Transistor), which is one of power switching elements, each phase IGBT depends on the operation state of the motor, such as a motor lock state. There is a risk that the temperature of the element rises and a failure occurs. For this reason, the temperature of each IGBT element is monitored, and when the monitor temperature becomes equal to or higher than a predetermined temperature, the output power of the inverter is reduced and the drive frequency of the IGBT element is reduced, thereby suppressing the temperature rise. Is usually done.

  In the comparative example, the inverter circuit and the temperature detection diode are mounted on the same substrate to form a chip, and the temperature during operation of the IGBT of the inverter circuit is detected. However, in this configuration, since the temperature detection diode and the temperature detection circuit are provided as separate chips, the detection accuracy decreases due to the influence of variations in the semiconductor elements.

  Further, in the conventional chip formation using a silicon semiconductor, since the use limit temperature (junction temperature) is 150 ° C., it is difficult to make the temperature detection diode and the temperature detection circuit into one chip.

  According to the third embodiment, the power element circuit configured by the power switching element, the temperature detecting diode 35 provided for measuring the temperature of the power switching element, and the voltage from the temperature detecting diode 35 And a temperature detection circuit 77a that detects the temperature based on the signal. The temperature detection diode 35 and the temperature detection circuit 77a are formed on one chip by the SOI structure. For this reason, the junction temperature increases, the relative accuracy between the semiconductor elements of the temperature detection circuit 77a and the temperature detection diode 35 is improved, and highly accurate temperature detection can be performed.

  The temperature detection apparatus according to the present invention can be applied to temperature detection of power devices such as inverters and switching elements that reach a high temperature state.

DESCRIPTION OF SYMBOLS 1,11 ... UVLO (undervoltage malfunction prevention) circuit 2, 3, 12, 16, 17, 47, 48, 50, 51, 56, 57, 58, 59 ... Inverter 4, 5, 14, 15, 52, 53 , 54, 55 ... Pulse generator 8, 18, 60, 61 ... RS flip-flop 9, 19, 62, 63 ... Buffer 10, 20, 120 ... Resistance 31, 32, 70, 71 ... Insulation transformer 31a, 31B, 32a 32b, inductor 35, 121, temperature sensor (temperature detection diode)
36, 37, 38, 42, 43a, 43b, 109, 110, 111, 112, 113, 303 ... FET
41, 104, 302 ... amplifier 43, 301 ... current mirror circuit 44, 107 ... AD conversion circuit 45, 200 ... digital comparison circuit 46, 163 ... oscillation circuit 49 ... comparator (comparator)
72 ... ECU
73, 74 ... Isolator 75 ... Gate driver 76, 77a, 100, 210 ... Temperature detection circuit 77 ... Power semiconductor module 77b ... Inverter circuit 78 ... DC power supply 80 ... Primary side circuit 81 ... Secondary side circuit 90 ... Temperature detection device DESCRIPTION OF SYMBOLS 101 ... Insulation transformer circuit 102 ... Signal demodulation circuit 105 ... Reference voltage generation circuit 108 ... Level shifter 141, 142, 151 ... Variable resistance 161 ... Digital comparator 162, 164 ... Counter 164a, 172, 175 ... DA converter 171 ... Successive comparison Register 173 ... Analog comparator 174 ... Register 410 ... Low voltage side substrate 411 ... High voltage side substrate 412 ... Motor

Claims (6)

A temperature detection circuit that outputs a first pulse signal corresponding to the temperature detected by the temperature sensor;
An insulation transformer that is provided between the temperature detection circuit and the integrated circuit and transmits the first pulse signal to an integrated circuit that operates at an operating voltage different from that of the temperature detection circuit;
Each of the temperature detection circuit and the insulation transformer has a quadrangular shape and is formed into a chip, and is arranged on the same frame so that one side of each chip faces,
A temperature detecting device, wherein a recess is provided in a boundary region of the frame between the chip of the insulating transformer and the chip of the temperature detecting circuit. The insulating transformer is
A primary coil through which a current flows based on a first pulse signal from the temperature detection circuit side and a secondary coil that generates a current to be transmitted to the integrated circuit side are formed above and below a dielectric layer. The temperature detection device according to claim 1, wherein:   The temperature detection circuit outputs a second pulse signal when the temperature detected by the temperature sensor reaches a predetermined limit value, and the isolation transformer outputs the second pulse signal from the temperature detection circuit. The temperature detection device according to claim 1, wherein the temperature detection device transmits the temperature to the integrated circuit.   A pulse generator that shapes the high-level pulse width and the low-level pulse width of the first pulse signal or the second pulse signal and makes the pulse width smaller than that of the pulse signal is the primary side of the isolation transformer. The temperature detection device according to claim 3, wherein the temperature detection device is provided in front of the coil.   A signal demodulating circuit for demodulating the pulse signal whose waveform is shaped by the pulse generator to the original pulse width is formed after the secondary coil of the insulating transformer that generates a current transmitted to the integrated circuit side. The temperature detection device according to claim 4, wherein:   The temperature detecting device according to claim 1, wherein the concave portion is extended in a direction parallel to one side of the chip.