JP2022071390A - Signal transmission device - Google Patents

Abstract

To provide a signal transmission device that uses a signal transmission device to reduce the cost or improve the robustness of the entire application.SOLUTION: A signal transmission device (insulation gate driver IC) 100 includes an isolated signal transmission circuit 10 that transmits an input pulse signal as an output pulse signal, and an insulation monitoring circuit 20 that monitors a plurality of monitored signals in a time-division manner. Further, the isolated signal transmission circuit transmits the input pulse signal of a primary circuit system 100p as an output pulse signal of a secondary circuit system via a first insulating element (transformer). The insulation monitoring circuit monitors a plurality of monitored signals in the secondary circuit system 100s in a time-division manner, and transmits each monitoring result from the secondary circuit system to the primary circuit system via a second insulating element (transformer).SELECTED DRAWING: Figure 1

Description

The invention disclosed herein relates to a signal transduction device.

Conventionally, a signal transmission device having a function of transmitting an input pulse signal as an output pulse signal (signal transmission function) has been put into practical use.

As an example of the prior art related to the above, Patent Document 1 can be mentioned.

Japanese Unexamined Patent Publication No. 2018-011108

By the way, some conventional signal transmission devices have not only the original signal transmission function but also a monitoring function for parameters (voltage, temperature, etc.) that need to be detected by the host device.

However, in view of cost reduction or improvement of robustness of the entire application using the signal transmission device, there is room for further improvement in the monitoring function of the signal transmission device.

The invention disclosed in the present specification is an object of the present invention to provide a signal transmission device which can contribute to cost reduction or improvement of robustness of an entire application in view of the above-mentioned problems found by the inventors of the present application. And.

For example, the signal transmission device disclosed in the present specification includes a signal transmission circuit that transmits an input pulse signal as an output pulse signal, and a monitoring circuit that monitors a plurality of monitored signals in a time-division manner ( The first configuration).

In the signal transmission device having the first configuration, the signal transmission circuit transmits the input pulse signal of the primary circuit system as the output pulse signal of the secondary circuit system via the first insulating element, and the signal transmission circuit is described. The monitoring circuit monitors the plurality of monitored signals in the secondary circuit system in a time-divided manner, and transmits each monitoring result from the secondary circuit system to the primary circuit system via the second insulating element ( The second configuration) may be used.

Further, in the signal transmission device having the second configuration, the monitoring circuit includes a pulse converter that converts the signal value of each of the plurality of monitored signals into a single monitoring result pulse signal (third configuration). Configuration) may be used.

Further, in the signal transmission device having the third configuration, the monitoring result pulse signal indicates a data pulse indicating the signal value of each of the plurality of monitoring target signals, and the data pulse indicates the signal value of which monitoring target signal. It may be configured to include an identification pulse for informing the user (fourth configuration).

Further, in the signal transmission device having any of the second to fourth configurations described above, the monitoring circuit includes a register for storing the signal values of each of the plurality of monitored signals (fifth configuration). You may do it.

Further, in the signal transmission device having any of the second to fifth configurations, the first chip in which the circuit elements of the primary circuit system are integrated and the second chip in which the circuit elements of the secondary circuit system are integrated are integrated. And the third chip in which the first insulating element and the second insulating element are integrated may be sealed in a single package (sixth configuration).

Further, in the signal transmission device having any of the second to sixth configurations, in the signal transmission circuit, the first transformer and the second transformer corresponding to the first insulating element and the input pulse signal are the first logic. The first transmission pulse signal applied to the primary winding of the first transformer is pulse-driven when notifying that the level is, and the first when notifying that the input pulse signal is the second logic level. A pulse transmission unit that pulse-drives the second transmission pulse signal applied to the primary winding of the two transformers, and a first reception that appears in the secondary winding of the first transformer after receiving the pulse drive of the first transmission pulse signal. Induction of pulse signal Induction of the second received pulse signal that appears in the secondary winding of the second transformer by receiving the pulse drive of the second transmission pulse signal with the received pulse signal as the first logic level when the pulse is detected. The configuration (seventh configuration) includes a pulse receiving unit that sets the received pulse signal as the second logic level when a pulse is detected, and a driver that generates the output pulse signal in response to the received pulse signal. May be good.

Further, in the signal transmission device having any of the first to seventh configurations, the plurality of monitored signals may be configured to include information on the monitored voltage and the monitored temperature, respectively (eighth configuration). good.

Further, the electronic device disclosed in the present specification includes a plurality of power transistors and a plurality of gate driver ICs for driving the gates of the plurality of power transistors, and the plurality of gate driver ICs of the plurality of gate driver ICs. At least one of them has a configuration (nineth configuration) which is a signal transmission device having any of the first to eighth configurations.

Further, the vehicle disclosed in the present specification has a configuration having an electronic device having the ninth configuration (tenth configuration).

According to the invention disclosed in the present specification, it is possible to provide a signal transmission device that can contribute to cost reduction or robustness improvement of the entire application.

The figure which shows the basic structure of a signal transmission device The figure which shows one configuration example of an isolated signal transmission circuit The figure which shows an example of the insulation signal transmission operation The figure which shows the 1st Embodiment of the insulation monitoring circuit. The figure which shows the 1st application example of a signal transmission device. The figure which extracts and shows only one phase of the 1st application example The figure which shows the 2nd Embodiment of the insulation monitoring circuit. The figure which shows the 1st example of the time division control The figure which shows the 2nd example of the time division control The figure which shows the 2nd application example of a signal transmission device. The figure which shows only one phase of the 2nd application example is extracted. The figure which shows the 3rd application example of a signal transmission device. Diagram showing the appearance of a vehicle equipped with electronic devices

<Signal transmission device (basic configuration)>
FIG. 1 is a diagram showing a basic configuration of a signal transmission device. The signal transmission device 100 of this configuration example has the primary circuit system 100p to the secondary circuit system 100s while insulating between the primary circuit system 100p (Vcc1-GND1 system) and the secondary circuit system 100s (Vcc2-GND2 system). It is a semiconductor integrated circuit device (so-called insulated gate driver IC) that transmits a pulse signal to and drives a gate of a power transistor (not shown) provided in the secondary circuit system 100s.

The signal transduction device 100 has a plurality of external terminals (in this figure, a VCC1 pin, an IN pin, an MO pin, a GND1 pin, a VCS2 pin, an OUT pin, etc.) as means for establishing an electrical connection with the outside of the device. The MI pin and the GND2 pin are exemplified).

In the primary circuit system 100p, the VCC1 pin (primary side power supply terminal) is connected to the power supply line (= application end of the power supply voltage Vcc1) of the primary circuit system 100p. The IN pin (pulse signal input terminal) is connected to an input pulse signal source (ECU [electric control unit] or the like) (not shown). The MO pin (monitor output terminal) is connected to a host device (ECU or the like) (not shown). The GND1 pin (primary side ground terminal) is connected to the ground line (= application end of the ground voltage GND1) of the primary circuit system 100p.

In the secondary circuit system 100s, the VCS2 pin (secondary power supply terminal) is connected to the power supply line (= application end of the power supply voltage Vcc2) of the secondary circuit system 100s. The OUT pin (pulse signal output terminal) is connected to the gate of a power transistor (not shown). The MI pin (monitor input terminal) is connected to a signal source to be monitored (not shown). The GND2 pin (secondary side ground terminal) is connected to the ground line (= application end of the ground voltage GND2) of the secondary circuit system 100s.

The signal transmission device 100 is used for all applications (motor drivers or DC / DC converters that handle high voltage, etc.) that need to transmit signals between the primary circuit system 100p and the secondary circuit system 100s while insulating them from each other. ) Can be widely applied.

Subsequently, the internal configuration of the signal transmission device 100 will be described with reference to FIG. The signal transmission device 100 of this configuration example includes a controller chip 110 (= corresponding to the first chip), a driver chip 120 (= corresponding to the second chip), and a transformer chip 130 (= corresponding to the third chip). Have.

The controller chip 110 is a semiconductor chip in which circuit elements of a primary circuit system 100p that operate by receiving a supply of a power supply voltage Vcc1 (for example, a maximum of 7V based on GND1) are integrated. The driver chip 120 is a semiconductor chip in which circuit elements of the secondary circuit system 100s that operate by being supplied with a power supply voltage Vcc2 (for example, a maximum of 30V based on GND2) are integrated. The transformer chip 130 is a semiconductor chip in which a transformer for bidirectional signal transmission is integrated while insulating between the controller chip 110 and the driver chip 120.

As described above, the signal transmission device 100 of this configuration example independently has a transformer chip 130 on which only a transformer is mounted, in addition to the controller chip 110 and the driver chip 120, and these three chips are packaged in a single package. It is sealed in.

With such a configuration, both the controller chip 110 and the driver chip 120 can be formed by a general low withstand voltage to medium withstand voltage process (withstand voltage of several V to several tens of V), and thus are dedicated. It is not necessary to use a high withstand voltage process (withstand voltage of several kV), and the manufacturing cost can be reduced.

Further, the controller chip 110 and the driver chip 120 can be created by an existing process with a proven track record, and there is no need to perform a new reliability test, so that the development period can be shortened and the development cost can be reduced. It can contribute to the reduction.

Further, even when an insulating element other than a transformer (for example, a photocoupler) is used, it is possible to easily deal with it by replacing only the transformer chip 130, so the controller chip 110 and the driver chip 120 have been developed. There is no need to redo, which can contribute to shortening the development period and reducing the development cost.

Next, focusing on the main functional block, the signal transmission device 100 includes an insulation signal transmission circuit 10 and an insulation monitoring circuit 20.

The isolated signal transmission circuit 10 is isolated from the primary circuit system 100p and the secondary circuit system 100s via an insulating element ISO1 (transformer or the like) integrated in the transformer chip 130, and is connected to the primary circuit system 100p to the secondary circuit system 100p. A pulse signal is transmitted to the next circuit system 100s. Speaking in accordance with this figure, the isolated signal transmission circuit 10 uses the input pulse signal S1 input to the IN pin of the primary circuit system 100p as the output pulse signal S2 output from the OUT pin of the secondary circuit system 100s. introduce.

The insulation monitoring circuit 20 is a host device (ECU or the like) while insulating between the primary circuit system 100p and the secondary circuit system 100s via an insulating element ISO2 (transformer or the like) integrated in the transformer chip 130. The parameters (voltage, temperature, etc.) of the secondary circuit system 100s that need to be detected are monitored, and the monitoring result is transmitted from the secondary circuit system 100s to the primary circuit system 100p. According to this figure, the insulation monitoring circuit 20 monitors the monitoring target signal S3 input to the MI pin of the secondary circuit system 100s, and the monitoring result pulse signal output from the MO pin of the primary circuit system 100p. It is transmitted as S4.

As described above, the signal transmission device 100 includes a transformer chip 130 in which the insulating element ISO1 originally used for signal transmission from the primary circuit system 100p to the secondary circuit system 100s is integrated. Therefore, by additionally integrating the insulation element ISO2 for insulation monitoring on the transformer chip 130, the monitoring result of the monitored signal S3 can be obtained from the secondary circuit system 100s to the primary circuit system 100p inside the signal transmission device 100. It becomes possible to transmit to.

The circuit elements of the insulation signal transmission circuit 10 and the insulation monitoring circuit 20 are dispersed and integrated in the controller chip 110, the driver chip 120, and the transformer chip 130 (details will be described later).

<Insulated signal transmission circuit>
FIG. 2 is a diagram showing a configuration example of the isolated signal transmission circuit 10. The isolated signal transmission circuit 10 of this configuration example includes a Schmid buffer 11, a pulse transmitting unit 12, a pulse receiving unit 13, a driver 14, and transformers 15 and 16 (corresponding to the above-mentioned insulating element ISO1). ..

The Schmidt buffer 11 is an example of waveform shaping means, and is connected between the IN pin and the pulse transmission unit 12.

The pulse transmission unit 12 pulse-drives either one of the transmission pulse signals S1a and S1b according to the logic level of the input pulse signal S1 input from the IN pin via the Schmidt buffer 11. For example, the pulse transmission unit 12 may drive a pulse signal S1a (single or multiple transmission pulses) applied to the primary winding 15p of the transformer 15 when notifying that the input pulse signal S1 is at a high level. Output) is performed to notify that the input pulse signal S1 is at a low level, and the transmission pulse signal S1b applied to the primary winding 16p of the transformer 16 is pulse-driven.

The Schmidt buffer 11 and the pulse transmission unit 12 are both integrated in the controller chip 110 of the primary circuit system 100p (Vcc1-GND1 system).

The pulse receiving unit 13 generates a received pulse signal S2c according to the received pulse signals S2a and S2b input from the transformers 15 and 16, respectively. For example, when the pulse receiving unit 13 receives the pulse drive of the transmitting pulse signal S1a and detects the induced pulse of the received pulse signal S2a appearing in the secondary winding 15s of the transformer 15, the received pulse signal S2c stands at a low level. Lower. On the other hand, when the pulse receiving unit 13 receives the pulse drive of the transmitting pulse signal S1b and detects the induced pulse of the received pulse signal S2b appearing in the secondary winding 16s of the transformer 16, the received pulse signal S2c stands at a high level. increase.

The driver 14 generates an output pulse signal S2 (= corresponding to a gate signal of a power transistor (not shown)) according to the received pulse signal S2c input from the pulse receiving unit 13. For example, when an inverter is used as the driver 14, the output pulse signal S2 becomes high level when the received pulse signal S2c is low level, and the output pulse signal S2 becomes low level when the received pulse signal S2c is high level. Become. That is, the logic level of the output pulse signal S2 is switched according to the logic level of the input pulse signal S1.

The pulse receiving unit 13 and the driver 14 are both integrated in the driver chip 120 of the secondary circuit system 100s (Vcc2-GND2 system).

The transformer 15 outputs the received pulse signal S2a from the secondary winding 15s in response to the transmission pulse signal S1a input to the primary winding 15p. On the other hand, the transformer 16 outputs the received pulse signal S2b from the secondary winding 16s in response to the transmission pulse signal S1b input to the primary winding 16p.

Both the transformers 15 and 16 are integrated in the transformer chip 130. The transformer chip 130 uses transformers 15 and 16 to insulate between the controller chip 110 and the driver chip 120, and uses the transmission pulse signals S1a and S1b input from the pulse transmission unit 12 as the reception pulse signals S2a and S2b, respectively. It is output to the pulse receiving unit 13.

As described above, due to the characteristics of the spiral coil used for inter-isolation communication, the input pulse signal S1 is separated into two transmission pulse signals S1a and S1b (= corresponding to the rise signal and the fall signal), and then two systems are used. It is transmitted from the primary circuit system 100p to the secondary circuit system 100s via the transformers 15 and 16.

FIG. 3 is a diagram showing an example of an isolated signal transmission operation by the isolated signal transmission circuit 10, in order from the top, an input pulse signal S1, a transmission pulse signal S1a and S1b, a reception pulse signal S2a to S2c, and an output pulse signal. S2 is depicted. In this figure, the description of the signal delay is omitted for convenience of explanation.

The pulse transmission unit 12 drives the transmission pulse signal S1a at the rising edge of the input pulse signal S1 at time t1, while driving the transmission pulse signal S1b at the falling edge of the input pulse signal S1 at time t2. The pulse receiving unit 13 detects the induced pulse of the received pulse signal S2a generated by the pulse drive of the transmitted pulse signal S1a and lowers the received pulse signal S2c to a low level, while the received pulse signal generated by the pulse drive of the transmitted pulse signal S1b. The induced pulse of S2b is detected and the received pulse signal S2c is raised to a high level. As a result, when the input pulse signal S1 rises to a high level, the output pulse signal S2 also rises to a high level, and conversely, when the input pulse signal S1 falls to a low level, the output pulse signal is matched accordingly. S2 also falls to the low level.

<Insulation monitoring circuit (first embodiment)>
FIG. 4 is a diagram showing a first embodiment of the insulation monitoring circuit 20. The insulation monitoring circuit 20 of the present embodiment includes a current source 21, a switch 22, a buffer 23, a pulse converter 24, a pulse transmission unit 25, a pulse reception unit 26, and transformers 27 and 28 (the above-mentioned insulation). (Equivalent to element ISO2) and.

The current source 21 generates a source current to the MI pin.

The switch 22 conducts / disconnects between the current source 21 and the MI pin. That is, when the switch 22 is on, the source current flows through the MI pin. On the other hand, when the switch 22 is off, the source current does not flow to the MI pin.

The buffer 23 transmits the monitored signal S3 externally input to the MI pin to the pulse converter 24 in the subsequent stage.

The pulse converter 24 generates a PWM [pulse width modulation] signal S10 having a duty corresponding to the signal value of the monitored signal S3 input via the buffer 23. For example, the higher the signal value of the monitored signal S3, the higher the duty of the PWM signal S10, and the lower the signal value of the monitored signal S3, the lower the duty. Contrary to the above, the higher the signal value of the monitored signal S3, the lower the duty of the PWM signal S10, and the lower the signal value of the monitored signal S3, the higher the duty of the PWM signal S10.

The pulse transmission unit 25 pulse-drives either one of the transmission pulse signals S11a and S11b according to the logic level of the PWM signal S10. For example, the pulse transmission unit 25 may drive the transmission pulse signal S11a (single-shot or multiple-shot transmission pulse) applied to the secondary winding 27s of the transformer 27 when notifying that the PWM signal S10 is at a high level. Output) is performed to notify that the PWM signal S10 is at a low level, and the pulse drive of the transmission pulse signal S11b applied to the secondary winding 28s of the transformer 28 is performed.

The current source 21, switch 22, buffer 23, pulse converter 24, and pulse transmission unit 25 are all integrated in the driver chip 120 of the secondary circuit system 100s (Vcc2-GND2 system).

The pulse receiving unit 26 generates a monitoring result pulse signal S4 according to the received pulse signals S12a and S12b input from the transformers 27 and 28, respectively, and outputs the monitoring result pulse signal S4 from the MO pin to a host device (ECU or the like). For example, when the pulse receiving unit 26 receives the pulse drive of the transmitting pulse signal S11a and detects the induced pulse of the received pulse signal S12a appearing in the primary winding 27p of the transformer 27, the monitoring result pulse signal S4 stands at a high level. increase. On the other hand, when the pulse receiving unit 26 receives the pulse drive of the transmitting pulse signal S11b and detects the induced pulse of the received pulse signal S12b appearing in the primary winding 28p of the transformer 28, the monitoring result pulse signal S4 stands at a low level. Lower. That is, the logic level of the monitoring result pulse signal S4 is switched according to the logic level of the PWM signal S10.

The pulse receiving unit 26 is integrated in the controller chip 110 of the primary circuit system 100p (Vcc1-GND1 system).

The transformer 27 outputs the received pulse signal S12a from the primary winding 27p in response to the transmission pulse signal S11a input to the secondary winding 27s. On the other hand, the transformer 28 outputs the received pulse signal S12b from the primary winding 28p in response to the transmission pulse signal S11b input to the secondary winding 28s.

Both the transformers 27 and 28 are integrated in the transformer chip 130. The transformer chip 130 uses transformers 27 and 28 to insulate the controller chip 110 and the driver chip 120, and uses the transmission pulse signals S11a and S11b input from the pulse transmission unit 25 as reception pulse signals S12a and S12b, respectively. It is output to the pulse receiving unit 26.

As described above, due to the characteristics of the spiral coil used for inter-isolation communication, the PWM signal S10 generated in the secondary circuit system 100s becomes the two transmission pulse signals S11a and S11b (= corresponding to the rise signal and the fall signal). After being separated, it is transmitted to the primary circuit system 100p via two systems of transformers 27 and 28.

Hereinafter, the signal transmission device 100 provided with the insulation monitoring circuit 20 of the first embodiment will be referred to as a “signal transmission device GD1” in order to distinguish it from the others.

<Example of first application>
FIG. 5 is a diagram showing a configuration example (corresponding to a first application example) of an electronic device using the signal transmission device GD1. The electronic device A of this configuration example includes an upper gate driver IC1H (u / v / w), a lower gate driver IC1L (u / v / w), an upper power transistor 2H (u / v / w), and a lower part. It has a side power transistor 2L (u / v / w), an ECU 3, a motor 4, a resistor 5H (u / v / w), and a resistor 5L (u / v / w).

The upper gate driver IC1H (u / v / w) insulates between the ECU 3 and the upper power transistor 2H (u / v / w), respectively, and the upper gate control signal (= input pulse signal) input from the ECU 3. The upper power transistor 2H (u / v / w) is driven by generating the upper gate drive signal (= output pulse signal S2) according to S1).

The lower gate driver IC 1L (u / v / w) insulates between the ECU 3 and the lower power transistor 2L (u / v / w), respectively, and the lower gate control signal (=) input from the ECU 3. The lower power transistor 2L (u / v / w) is driven by generating the lower gate drive signal (= output pulse signal S2) in response to the input pulse signal S1).

In this figure, the upper gate driver IC1H (u / v / w) and the lower gate driver IC1L (u / v / w) are both signal transmission devices GD1 provided with the insulation monitoring circuit 20 of the first embodiment. (Fig. 4) is used.

The upper power transistor 2H (u / v / w) serves as an upper switch forming a three-phase (U-phase / V-phase / W-phase) half-bridge output stage, respectively, as a power system power supply end (= motor drive voltage P VDD). It is connected between the application end) and each phase input end of the motor 4.

The lower power transistor 2L (u / v / w) serves as a lower switch forming a three-phase (U-phase / V-phase / W-phase) half-bridge output stage, respectively, with each phase input end of the motor 4 and power. It is connected to the system grounding end.

The upper power transistor 2H (u / v / w) and the lower power transistor 2L (u / v / w) each include a temperature sensor TaD (for example, a silicon diode) for detecting the ambient temperature Ta. .. Therefore, if it is necessary to obtain information on the ambient temperature Ta, a source current is passed through the temperature sensor TaD, and the temperature detection voltage V2 (u / v / w) (for example, the forward voltage drop of the silicon diode that fluctuates depending on the temperature). It suffices to read (corresponding to Vf).

Further, in this figure, N-channel MOSFETs [metal oxide semiconductor field effect transistors] are used as the upper power transistor 2H (u / v / w) and the lower power transistor 2L (u / v / w), respectively. However, for example, a P-channel type MOSFET may be used as the upper power transistor 2H (u / v / w). It is also possible to use an IGBT [insulated gate bipolar transistor] instead of the MOSFET.

The ECU 3 has an upper power transistor 2H (u / v / w) and a lower power transistor 2L (u) via the upper motor driver IC1H (u / v / w) and the lower motor driver IC1L (u / v / w). By driving / v / w) respectively, the rotational drive of the motor 4 is controlled. Further, the ECU 3 has an overvoltage based on the monitoring results obtained by the insulation monitoring circuits 20 (not shown) of the upper motor driver IC1H (u / v / w) and the lower motor driver IC1L (u / v / w). It also has a function to perform protection operation and overheat protection operation.

The motor 4 is a three-phase motor that is rotationally driven according to the three-phase drive voltage U / V / W input from each of the three-phase (U-phase / V-phase / W-phase) half-bridge output stages.

The resistance 5H (u / v / w) and the resistance 5L (u / v / w) are connected in series between the power system power supply end and the power system grounding end, respectively, and are driven by a motor from the connection node of each phase. The voltage divider voltage V1 (u / v / w) corresponding to the voltage P VDD (for example, 48V to 700V) is output.

In the first application example of this figure, the voltage dividing voltage V1 (u / v / w) is input to the upper gate driver IC1H (u / v / w), respectively. Further, a temperature detection voltage V2 (u / v / w) is input to each of the lower gate driver IC1L (u / v / w). That is, the upper gate driver IC1H (u / v / w) is used to indirectly monitor the motor drive voltage P VDD, while the lower gate driver IC1L (u / v / w) is used to monitor the ambient temperature Ta. In addition, each insulation monitoring circuit 20 is used properly.

FIG. 6 is a diagram showing only one phase of the first application example (FIG. 5) extracted. For convenience of illustration, the output end of the pulse converter 24 is depicted as if it were directly connected to the MO pin, but in reality, the pulse transmitter 25 is located between the pulse converter 24 and the MO pin. A transformer 27 and a pulse receiving unit 26 are provided (see FIG. 4 above).

As shown in this figure, the MI pin of the upper gate driver IC1H is a connection node between the resistors 5H and 5L. Therefore, the voltage dividing voltage V1 is input to the insulation monitoring circuit 20 as the monitoring target signal S3. At this time, since the switch 22 is turned off, the source current does not flow from the current source 21 to the MI pin.

On the other hand, the MI pin of the lower gate driver IC 1L is connected to the temperature sensor TaD of the lower power transistor 2L. At this time, since the switch 22 is turned on, the source current flows from the current source 21 to the MI pin (and thus the temperature sensor TaD). Therefore, the temperature detection voltage V2 is input to the insulation monitoring circuit 20 as the monitoring target signal S3.

With such a configuration, the ECU 3 acquires information on the motor drive voltage P VDD based on the monitoring result signal S4 input from the upper gate driver IC1H, while the monitoring result signal S4 input from the lower gate driver IC1L. Information on the ambient temperature Ta can be obtained based on.

However, in the first application example in which the signal transmission device GD1 is used as the upper gate driver IC1H (u / v / w) and the lower gate driver IC1L (u / v / w), cost reduction and quality improvement (robust) are performed. There was room for consideration regarding (improvement of sex).

First, consider the cost aspect. In the first application example described above, the insulation monitoring circuit 20 is incorporated in all six signal transmission devices GD1. However, when monitoring DC voltage or temperature without instantaneous fluctuation (variation in units of several ms), the specification to provide the insulation monitoring circuit 20 in all six signal transmission devices GD1 is wasteful and may be a factor of cost increase. ..

Even when monitoring only one of the phases, in order to monitor both the motor drive voltage P whether and the ambient temperature Ta, at least two signal transmission devices GD1 above and below must be provided with insulation monitoring circuits 20. , There was room for further cost reduction.

Next, we will consider quality improvement (improvement of robustness). The electronic device A of the first application example has six signal transmission devices GD1, and each signal transmission device GD1 has a voltage dividing voltage V1 (and thus a motor drive voltage P VDD) and a temperature detection voltage V2. Cannot be monitored at the same time. Therefore, in a system in which high quality is required for the voltage monitoring function and the temperature monitoring function by the ECU 3, there is a limitation in improving the robustness.

In the following, we propose a new embodiment that can solve such a problem.

<Insulation monitoring circuit (second embodiment)>
FIG. 7 is a diagram showing a second embodiment of the insulation monitoring circuit 20. The insulation monitoring circuit 20 of the present embodiment monitors the monitoring target signal S3a (= voltage information) input to the MI1 pin and the monitoring target signal S3b (= temperature information) input to the MI2 pin on a time-division basis, respectively. It has a function (time division monitoring function) of transmitting the monitoring result of the above from the secondary circuit system 100s to the primary circuit system 100p via the transformer 27.

In order to realize such a time-division monitoring function, in the insulation monitoring circuit 20 of the present embodiment, the switch 22 is removed, and the multiplexer 29 and the controller are used based on the first embodiment (FIG. 4) described above. 2A has been added. Further, the number of MI pins is increased from one to two (MI1 pin and MI2 pin). The current source 21 is connected to the MI2 pin.

The multiplexer 29 selectively outputs one of the monitoring target signals S3a and S3b input to the MI1 pin and MI2 as the monitoring target signal S3 to the buffer 23. When the multiplexer 29 is provided outside the signal transmission device 100, the MI pin may be one input. However, in that case, an external terminal for controlling the multiplexer is required separately. Also, the switch 22 cannot be omitted.

The controller 2A controls the multiplexer 29 and the pulse converter 24 at predetermined timings so as to monitor the monitoring target signals S3a and S3b in a time-division manner.

For example, the controller 2A controls the multiplexer 29 to selectively output the monitoring target signal S3a input to the MI1 pin as the monitoring target signal S3 during the period T1 in which the monitoring target signal S3a should be monitored, and the monitoring target signal. During the period T2 in which S3b should be monitored, the multiplexer 29 is controlled so that the monitoring target signal S3b input to the MI2 pin is selectively output as the monitoring target signal S3. Therefore, in the pulse converter 24, the signal values of the monitored signals S3a and S3b are converted into a single PWM signal S10 (and thus the monitoring result pulse signal S4) by time division (details will be described later).

Further, for example, in the controller 2A, whether the PWM signal S10 generated by the pulse converter 24 indicates the signal value (= voltage information) of the monitored signal S3a or the signal value (= temperature information) of the monitored signal S3b. The pulse converter 24 is controlled so as to generate an identification pulse for informing the ECU 3 of the above (details will be described later).

In this figure, an example of performing PWM output from the insulation monitoring circuit 20 to the host 3 (not shown) as a means for notifying the monitoring result is given, but the means for notifying the monitoring result is arbitrary. For example, the insulation monitoring circuit 20 is provided with a register for storing the signal values of the monitored signals S3a and S3b, and the CPU [central processing] such as I ^2C [inter-integrated circuit] or UART [universal asynchronous receiver / transmitter]. The monitoring result may be notified to the ECU 3 by using the unit] interface or the interface conforming to the communication standard for vehicles such as LIN [local interconnect network] and CAN [controller area network].

<Time division control>
FIG. 8 is a diagram showing a first example of time division control by the insulation monitoring circuit 20 of the second embodiment. As shown in this figure, the monitoring result pulse signal S4 alternately includes the header pulse HP and the data pulse DP.

The header pulse HP tells the ECU 3 whether the data pulse DP following it indicates the signal value (= voltage information) of the monitored signal S3a or the signal value (= temperature information) of the monitored signal S3b. It corresponds to the identification pulse for notifying.

The data pulse DP corresponds to a PWM signal S10 having a duty corresponding to the signal value of the monitored signal S3a or S3b.

For example, in the period T1, after the header pulse HP, which is longer than one cycle of the data pulse DP and is fixed at a low level for a certain period of time, is output as the monitoring result pulse signal S4, the signal value of the monitoring target signal S3a (=). A data pulse DP having a duty according to the voltage information) is output. The low-level fixed header pulse HP indicates that the data pulse DP following this is the signal value (= voltage information) of the monitored signal S3a. Therefore, the ECU 3 can acquire the voltage information of the secondary circuit system 100s from the monitoring result pulse signal S4 in the period T1.

On the other hand, in the period T2, after the header pulse HP, which is longer than one cycle of the data pulse DP and is fixed at a high level for a certain period of time, is output as the monitoring result pulse signal S4, the signal value of the monitoring target signal S3b (=). A data pulse DP having a duty according to the temperature information) is output. The high-level fixed header pulse HP indicates that the data pulse DP following this is the signal value (= temperature information) of the monitored signal S3b. Therefore, the ECU 3 can acquire the temperature information of the secondary circuit system 100s from the monitoring result pulse signal S4 in the period T2.

As described above, in the case of the insulation monitoring circuit 20 of the second embodiment, by periodically repeating the periods T1 and T2, the signal values of the monitored signals S3a and S3b are set using the single monitoring result signal S4. It is possible to output to the ECU 3 in a time division manner.

FIG. 9 is a diagram showing a second example of time division control by the insulation monitoring circuit 20 of the second embodiment. As shown in this figure, the header pulse HP is not necessarily limited to high level fixed or low level fixed, and the data pulse DP following it indicates any signal value of the monitored signals S3a and S3b. It suffices if it can be uniquely identified.

For example, when the PWM signal is adopted as the header pulse HP, the header pulse HP is set to high duty when the data pulse DP indicates the signal value (= voltage information) of the monitoring target signal S3a, and the data pulse DP is the monitoring target signal. When the signal value (= temperature information) of S3b is shown, the header pulse HP may be set to low duty. At this time, it is desirable to make each cycle inconsistent, such as making one cycle of the header pulse HP shorter than one cycle of the data pulse DP so that the header pulse HP and the data pulse DP can be clearly distinguished. In particular, the time division control of the second example is effective when the number of monitored signals is three or more.

Further, in the above, the example in which the header pulse HP is added before the data pulse DP is given, but the footer pulse may be added after the data pulse DP to output in the frame format.

Hereinafter, the signal transmission device 100 provided with the insulation monitoring circuit 20 of the second embodiment will be referred to as a “signal transmission device GD2” in order to distinguish it from the others. Further, the inexpensive signal transmission circuit 100 not provided with the insulation monitoring circuit 20 is referred to as a "signal transmission device GD0" in order to distinguish it from others.

<Example of second application>
FIG. 10 is a diagram showing an example of a configuration (corresponding to a second application example) of an electronic device using the signal transmission device GD2.

The electronic device A of this configuration example is based on the first application example (FIG. 5) described above, and the signal transmission device GD2 (FIG. 7) is used as the lower gate driver IC1Lw, while the other upper gate driver IC1H. As (u / v / w) and the lower gate driver IC1L (u / v), an inexpensive signal transmission device GD0 is used.

Further, in the electronic device A of this configuration example, unnecessary resistance 5H (u / v) and resistance 5L (u / v) are removed.

In the second application example of this figure, both the voltage dividing voltage V1w and the temperature detection voltage V2w are input to the lower gate driver IC1Lw. That is, the monitoring functions are integrated in the lower gate driver IC1Lw so that both the motor drive voltage P VDD and the ambient temperature Ta are time-division-monitored only by the lower gate driver IC1Lw. On the other hand, the other five gate driver ICs have been integrated into a single function for cost reduction.

The signal transmission device GD2 does not necessarily have to be used as the lower gate driver IC1Lw of the W phase, and of the six upper gate driver IC1H (u / v / w) and the lower gate driver IC1L (u / v / w). One of them may be a signal transmission device GD2.

FIG. 11 is a diagram showing only one phase of the second application example (FIG. 10) extracted. For convenience of illustration, the output end of the pulse converter 24 is depicted as if it were directly connected to the MO pin, but in reality, the pulse transmitter 25 and the transformer are located between the pulse converter 24 and the MO pin. 27 and a pulse receiving unit 26 are provided (see FIG. 7 above).

As shown in this figure, as the upper gate driver IC1H, a signal transmission device GD0 having no insulation monitoring circuit 20 is used. On the other hand, the lower gate driver IC1L incorporates an insulation monitoring circuit 20 having a time division monitoring function.

The MI1 pin of the lower gate driver IC1L is a connection node between the resistors 5H and 5L. Therefore, the voltage dividing voltage V1 is input to the insulation monitoring circuit 20 as the monitoring target signal S3a.

On the other hand, the MI2 pin of the lower gate driver IC1L is connected to the temperature sensor TaD of the lower power transistor 2L. Since the current source 21 is connected to the MI2 pin, the source current flows from the current source 21 to the MI2 pin (and thus the temperature sensor TaD). Therefore, the temperature detection voltage V2 is input to the insulation monitoring circuit 20 as the monitoring target signal S3b.

As described above, the controller 2A controls the multiplexer 29 and the pulse converter 24 at predetermined timings so as to monitor the monitored signals S3a and S3b in a time-division manner. Then, the monitoring results of the monitoring target signals S3a and S3b are transmitted from the lower gate driver IC1L to the ECU 3 in a time-division manner.

With such a configuration, the ECU 3 can acquire both the information regarding the motor drive voltage P whether and the information regarding the ambient temperature Ta based on the monitoring result signal S4 input from the lower gate driver IC1L.

In particular, of the six upper gate driver IC1H (u / v / w) and the lower gate driver IC1L (u / v / w), only one is used as the signal transmission device GD2, and the rest is the inexpensive signal transmission device GD0. If so, the cost of the entire application can be significantly reduced.

<Example of third application>
FIG. 12 is a diagram showing another configuration example (corresponding to a third application example) of an electronic device using the signal transmission device GD2. The second application example (FIG. 10) mentioned above is an example that emphasizes cost reduction, while the third application example emphasizes quality improvement (improvement of robustness) and six upper gate drivers IC1H (u / / Both v / w) and the lower gate driver IC1L (u / v / w) are referred to as a signal transmission device GD2.

That is, the upper gate driver IC1H (u / v / w) and the lower gate driver IC1L (u / v / w) have a voltage dividing voltage V1 (u / v / w) and temperature detection voltages V2H and V2L, respectively. Both (u / v / w) are input, and each monitoring result (= voltage information and temperature information) is transmitted to the ECU 3 in a time division.

With such a configuration, the ECU 3 has six systems based on the monitoring result signals S4 input from the upper gate driver IC1H (u / v / w) and the lower gate driver IC1L (u / v / w), respectively. It is possible to acquire information on the motor drive voltage P VDD and information on the ambient temperature Ta of the six systems.

Therefore, in the ECU 3, for example, for each of the voltage information or temperature information of the 6 systems, the quality improvement processing of each monitoring function (adoption of the majority voting method, calculation of the average value, or non-adoption of the deviation value deviating from other signal values is adopted. Etc.) can be carried out. As a result, it becomes possible to improve the quality (improvement of robustness) of the voltage monitoring function and the temperature monitoring function by the ECU 3.

The monitoring circuit capable of monitoring a plurality of monitored signals in a time-division manner can be applied not only to an isolated signal transmission device but also to a non-isolated signal transmission device.

<Application to vehicles>
FIG. 13 is a diagram showing the appearance of a vehicle on which an electronic device is mounted. The vehicle X of this configuration example is equipped with various electronic devices X11 to X18 that operate by receiving electric power from a battery (not shown). The mounting positions of the electronic devices X11 to X18 in this figure may differ from the actual mounting positions for convenience of illustration.

The electronic device X11 is an engine control unit that performs control related to the engine (injection control, electronic throttle control, idling control, oxygen sensor heater control, auto cruise control, etc.).

The electronic device X12 is a lamp control unit that controls turning on and off such as HID [high intensity discharged lamp] or DRL [daytime running lamp].

The electronic device X13 is a transmission control unit that performs control related to the transmission.

The electronic device X14 is a braking unit that performs control related to the motion of the vehicle X (ABS [anti-lock brake system] control, EPS [electric power steering] control, electronic suspension control, etc.).

The electronic device X15 is a security control unit that controls drive such as a door lock or a security alarm.

The electronic device X16 is an electronic device incorporated in the vehicle X at the factory shipment stage as a standard equipment or a manufacturer's option such as a wiper, an electric door mirror, a power window, a damper (shock absorber), an electric sunroof, and an electric seat. Is.

The electronic device X17 is an electronic device that is optionally mounted on the vehicle X as a user option such as an in-vehicle A / V [audio / visual] device, a car navigation system, and an ETC [electronic toll collection system].

The electronic device X18 is an electronic device provided with a high withstand voltage motor such as an in-vehicle blower, an oil pump, a water pump, and a battery cooling fan.

The electronic devices X11 to X18 can be understood as specific examples of the electronic device A described above. That is, the signal transmission device 100 described above can be incorporated into any of the electronic devices X11 to X18.

<Other variants>
In addition to the above-described embodiments, the various technical features disclosed in the present specification can be modified in various ways without departing from the spirit of the technical creation. That is, it should be considered that the above embodiment is exemplary in all respects and is not restrictive, and the technical scope of the present invention is not limited to the above embodiment and is claimed. It should be understood that the meaning of scope and equality and all changes belonging to the scope are included.

1H (u / v / w) Upper gate driver IC
1L (u / v / w) Lower gate driver IC
2H (u / v / w) Upper power transistor 2L (u / v / w) Lower power transistor 3 ECU
4 Motor 5H (u / v / w) Resistance 5L (u / v / w) Resistance 10 Insulated signal transmission circuit 11 Schmidt buffer 12 Pulse transmitter 13 Pulse receiver 14 Driver 15, 16 Transformer 15p, 16p Primary winding 15s, 16s secondary winding 20 insulation monitoring circuit 21 current source 22 switch 23 buffer 24 pulse converter 25 pulse transmitter 26 pulse receiver 27, 28 transformer 27p, 28p primary winding 27s, 28s secondary winding 29 multiplexer 2A controller 100 Signal transmission device (insulated gate driver IC)
100p primary circuit system 100s secondary circuit system 110 controller chip 120 driver chip 130 transformer chip A electronic device DP data pulse GD0, GD1, GD2 signal transmission device HP header pulse TaD temperature sensor X vehicle X11 to X18 electronic device

Claims (10)

A signal transmission circuit that transmits an input pulse signal as an output pulse signal,
A monitoring circuit that monitors multiple monitored signals in a time-division manner,
A signal transduction device. The signal transmission circuit transmits the input pulse signal of the primary circuit system as the output pulse signal of the secondary circuit system via the first insulating element.
The monitoring circuit monitors the plurality of monitored signals in the secondary circuit system in a time-division manner, and transmits each monitoring result from the secondary circuit system to the primary circuit system via the second insulating element. The signal transmission device according to claim 1. The signal transmission device according to claim 2, wherein the monitoring circuit includes a pulse converter that converts a signal value of each of the plurality of monitored signals into a single monitoring result pulse signal. 3. The monitoring result pulse signal includes a data pulse indicating a signal value of each of the plurality of monitoring target signals and an identification pulse for informing which monitoring target signal the data pulse indicates the signal value of which monitoring target signal. The signal transmission device according to. The signal transmission device according to any one of claims 2 to 4, wherein the monitoring circuit includes a register for storing a signal value of each of the plurality of monitored signals. The first chip, which integrates the circuit elements of the primary circuit system,
The second chip, which integrates the circuit elements of the secondary circuit system,
A third chip in which the first insulating element and the second insulating element are integrated,
The signal transduction device according to any one of claims 2 to 5, wherein the signal transduction device is sealed in a single package. The signal transmission circuit is
The first transformer and the second transformer corresponding to the first insulating element,
When notifying that the input pulse signal is at the first logic level, the first transmission pulse signal applied to the primary winding of the first transformer is pulse-driven, and the input pulse signal is at the second logic level. A pulse transmission unit that pulse-drives the second transmission pulse signal applied to the primary winding of the second transformer when notifying the effect.
When the induced pulse of the first received pulse signal appearing in the secondary winding of the first transformer is detected by receiving the pulse drive of the first transmission pulse signal, the received pulse signal is set to the first logic level and the second transmission is performed. A pulse receiving unit that sets the received pulse signal as the second logic level when the induced pulse of the second received pulse signal appearing in the secondary winding of the second transformer is detected by receiving the pulse drive of the pulse signal.
A driver that generates the output pulse signal in response to the received pulse signal,
The signal transmission device according to any one of claims 2 to 6, comprising the above. The signal transmission device according to any one of claims 1 to 7, wherein each of the plurality of monitored signals includes information regarding a monitored voltage and a monitored temperature. It has a plurality of power transistors and a plurality of gate driver ICs for driving the gates of the plurality of power transistors, and at least one of the plurality of gate driver ICs is any one of claims 1 to 8. An electronic device, which is the signal transmission device according to the first item. A vehicle having the electronic device according to claim 9.

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