Circuit arrangement and power inverter circuit

Abstract

To easily identify an alarm signal and a state signal.SOLUTION: A circuit arrangement comprises: a power inverter circuit; and a transmission device that transmits a signal from the power inverter circuit. The power inverter circuit provides the circuit arrangement having: an alarm signal generation part that generates an alarm signal indicating whether or not the power inverter circuit is previously set; and a state signal generation part that includes an oscillation that is different from the alarm signal, and generates a state signal indicating a state of the power inverter circuit. The power inverter circuit further includes an output terminal that outputs an output signal to which the alarm signal and the state signal are overlapped.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a circuit device and a power conversion circuit. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in a circuit such as a power conversion circuit, there is known a technique for outputting to the outside an alarm signal indicating an abnormality in the circuit or a temperature information signal indicating the temperature of the circuit (see, for example, Patent Documents 1 to 3). Patent Document 1: JP 2014-93903 A Patent Document 2: JP 2011-172336 A Patent Document 3: JP 2020-96436 A Summary of the Invention [Problem to be solved by the invention]

[0003] It is preferable to be able to easily distinguish between an alarm signal and a status signal indicating a condition such as temperature. [Means for solving the problem]

[0004] In order to solve the above problems, one aspect of the present invention provides a circuit device including a power conversion circuit and a transmission device that transmits a signal from the power conversion circuit. In the circuit device, the power conversion circuit may have an alarm signal generating unit that generates an alarm signal indicating whether the power conversion circuit has reached a preset state. In any of the circuit devices, the power conversion circuit may have a status signal generating unit that generates a status signal having an amplitude different from that of the alarm signal and indicating a status of the power conversion circuit.

[0005] In any of the circuit devices described above, the power conversion circuit may have an output terminal that outputs an output signal on which the alarm signal and the status signal are superimposed.

[0006] In any of the above circuit devices, the alarm signal generating unit may switch between a reference voltage and a first power supply voltage different from the reference voltage to be applied to the output terminal. In any of the above circuit devices, the status signal generating unit may switch between an intermediate voltage closer to the first power supply voltage than the reference voltage and the first power supply voltage to be applied to the output terminal.

[0007] In any of the above circuit devices, the power conversion circuit may have a reference wiring to which the reference voltage is applied. In any of the above circuit devices, the power conversion circuit may have a power supply wiring to which the first power supply voltage is applied. In any of the above circuit devices, the status signal generation unit may have a first switch provided between the reference wiring and the power supply wiring. In any of the above circuit devices, the status signal generation unit may have an intermediate voltage generation unit provided between the first switch and the reference wiring and generating the intermediate voltage.

[0008] In any of the circuit devices described above, the alarm signal generating section may have a second switch that switches whether the reference voltage or the first power supply voltage is to be applied to the output terminal.

[0009] In any of the above circuit devices, the transmission device may have a first transmission section that transmits a component of the output signal having an amplitude larger than a first reference value.In any of the above circuit devices, the transmission device may have a second transmission section that transmits a component of the output signal having an amplitude larger than a second reference value.In any of the above circuit devices, the first reference value may be smaller than the second reference value.

[0010] In any of the above circuit devices, the amplitude of the status signal may be greater than the first reference value and less than the second reference value. In any of the above circuit devices, the amplitude of the alarm signal may be greater than the second reference value.

[0011] In any of the above circuit devices, the amplitude of the status signal may be greater than the second reference value. In any of the above circuit devices, the amplitude of the alarm signal may be greater than the first reference value and less than the second reference value.

[0012] In any of the above circuit devices, the power conversion circuit may have an amplitude switching unit that switches which of the alarm signal and the status signal has an amplitude greater than the second reference value and which of the alarm signal and the status signal has an amplitude greater than the first reference value and less than the second reference value.

[0013] In any of the above circuit devices, the transmission device may have a second power supply voltage generating section that generates a second power supply voltage between the reference voltage and the intermediate voltage.In any of the above circuit devices, the transmission device may have a first transmission section that outputs a signal corresponding to a difference between the first power supply voltage and a voltage at the output terminal.In any of the above circuit devices, the transmission device may have a second transmission section that outputs a signal corresponding to a difference between the second power supply voltage and a voltage at the output terminal.

[0014] In any of the circuit devices described above, the second power supply voltage generating section may be a power supply that generates the second power supply voltage higher than the reference voltage, using the reference voltage as a reference.

[0015] In any of the circuit devices described above, the second power supply voltage generating section may be a step-down circuit that generates the second power supply voltage by stepping down the first power supply voltage with the first power supply voltage as a reference.

[0016] In any of the circuit devices described above, a stop signal for stopping a power conversion operation may be input to the power conversion circuit, and the power conversion circuit may continue to output the state signal even after the stop signal is input.

[0017] In any of the circuit devices described above, the status signal may be a signal indicating any one of a temperature, a current, and a voltage state of the power conversion circuit. In any of the circuit devices described above, the status signal generating unit may generate the status signal.

[0018] In a second aspect of the present invention, there is provided a power conversion circuit. The power conversion circuit may include an alarm signal generating unit that generates an alarm signal indicating whether the power conversion circuit has reached a preset state. Any of the power conversion circuits may include a status signal generating unit that generates a status signal having an amplitude different from that of the alarm signal and indicating a state of the power conversion circuit.

[0019] Any of the power conversion circuits described above may include an output terminal that outputs an output signal on which the alarm signal and the status signal are superimposed.

[0020] In any of the above power conversion circuits, the alarm signal generating unit may switch between a reference voltage and a first power supply voltage different from the reference voltage to be applied to the output terminal. In any of the above power conversion circuits, the status signal generating unit may switch between an intermediate voltage closer to the first power supply voltage than the reference voltage and the first power supply voltage to be applied to the output terminal.

[0021] Any of the above power conversion circuits may include a reference wiring to which the reference voltage is applied. Any of the above power conversion circuits may include a power supply wiring to which the first power supply voltage is applied. In any of the above power conversion circuits, the status signal generation unit may include a first switch provided between the reference wiring and the power supply wiring. In any of the above power conversion circuits, the status signal generation unit may include an intermediate voltage generation unit provided between the first switch and the reference wiring and generating the intermediate voltage.

[0022] In any of the power conversion circuits described above, the alarm signal generating section may have a second switch that switches whether the reference voltage or the first power supply voltage is to be applied to the output terminal.

[0023] Any of the power conversion circuits may include an amplitude switching section that switches between the alarm signal and the status signal so that the amplitude of either signal is made larger than the amplitude of the other signal.

[0024] In any of the circuit devices described above, the status signal may be a signal indicating any one of a temperature, a current, and a voltage state of the power conversion circuit. In any of the circuit devices described above, the status signal generating unit may generate the status signal.

[0025] The above summary of the invention does not list all of the features of the present invention. In addition, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0026] [Figure 1] 1 is a diagram showing an example of a circuit device 10 according to an embodiment of the present invention. [Diagram 2] 2 is a diagram illustrating an example of the configuration of a power conversion circuit 200 and a portion of a transmission device 300. FIG. [Diagram 3] 4 is a timing chart showing an example of an output signal OS, a signal VM1, and a signal VM2. [Figure 4] FIG. 13 illustrates another exemplary configuration of the transmission device 300. [Diagram 5] FIG. 4 is a diagram illustrating another configuration example of the power conversion circuit 200. [Figure 6] 6 is a timing chart showing an example of an output signal OS, a signal VM1, and a signal VM2 in the configuration shown in FIG. 5. [Figure 7] FIG. 4 is a diagram illustrating another configuration example of the power conversion circuit 200. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention will be described below through the embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present invention are not shown. In addition, in one drawing, elements having the same functions and configurations may be given the same reference numerals as representative elements, and the reference numerals may be omitted for the others.

[0028] In this specification, when the term "same" or "equal" is used, it may include cases where there is an error due to manufacturing variations, etc. The error is, for example, within 10%.

[0029] FIG. 1 is a diagram showing an example of a circuit device 10 according to an embodiment of the present invention. The circuit device 10 includes one or more power conversion circuits 200 and a transmission device 300. The circuit device 10 may further include a control circuit 100. The transmission device 300 transmits a signal between the power conversion circuit 200 and the control circuit 100. The transmission device 300 may be provided for each power conversion circuit 200. The power conversion circuit 200 may output power to another circuit of a target device in which the circuit device 10 is provided. As an example, the control circuit 100 is a computer provided in the target device. The control circuit 100 may control a circuit other than the power conversion circuit 200 of the target device. As an example, the target device is a car or an industrial robot, but is not limited thereto.

[0030] The power conversion circuit 200 converts input power into a predetermined output power. As an example, the power conversion circuit 200 is an AC / DC converter that converts DC power into AC power, but the form of the power conversion circuit 200 is not limited to this. The power conversion circuit 200 may include a power semiconductor such as an IGBT. The power conversion circuit 200 may include an inverter. The power conversion circuit 200 may supply power to an electric motor such as a motor.

[0031] The control circuit 100 controls the power conversion circuit 200. The control circuit 100 may control the on and off of the operation of the power conversion circuit 200, and may control the amplitude or frequency of the power output by the power conversion circuit 200. The control circuit 100 of this example transmits a control signal to each power conversion circuit 200. The control signal may control the switching of a transistor inside the power conversion circuit 200.

[0032] The power conversion circuit 200 has a control terminal 202 and an output terminal 204. A control signal from the control circuit 100 is input to the control terminal 202 via the transmission device 300. The output terminal 204 outputs an output signal to the control circuit 100. The output signal is transmitted by the transmission device 300.

[0033] The output signal includes an alarm signal and a status signal. The alarm signal is a signal indicating whether the power conversion circuit 200 has entered a preset state. The state may be an abnormal state such as an overcurrent state in which a current of a predetermined value or more flows at a predetermined point of the power conversion circuit 200, an overvoltage state in which a voltage of a predetermined value or more is applied to a predetermined point of the power conversion circuit 200, or an overheat state in which the temperature at a predetermined point of the power conversion circuit 200 has exceeded a predetermined value. The power conversion circuit 200 may change the pulse width of the alarm signal depending on the type of abnormal state. This allows the control circuit 100 to detect the type of abnormality that has occurred in the power conversion circuit 200.

[0034] The status signal is a signal indicating the status of the power conversion circuit 200 at a predetermined location of the power conversion circuit 200. The status of the power conversion circuit 200 may be the status of one or more parameters among the temperature, current, and voltage at the location. The status signal may be a signal indicating the numerical value of the status such as temperature, current, or voltage. The numerical value of the status such as temperature, current, or voltage is indicated by the width of a pulse included in the status signal. In another example, the numerical value of the status such as temperature, current, or voltage may be indicated by the density of a pulse. The numerical values ​​of multiple parameters may be indicated using different characteristics of the pulse. For example, the numerical value of one of the parameters among the temperature, current, and voltage may be indicated by the width of a pulse, and the numerical value of one of the other parameters may be indicated by the density of a pulse. The status signal may be generated in response to a request from the control circuit 100, or may be generated in response to a predetermined trigger. The output signal in this example includes a pulse of an alarm signal and a pulse of a status signal. By outputting the alarm signal and the status signal from a common output terminal 204, the number of terminals of the power conversion circuit 200 can be reduced.

[0035] The control circuit 100 of this example has a control output terminal 102, a status signal input terminal 106, and an alarm input terminal 108. The control output terminal 102 outputs a control signal. The status signal included in the output signal is input to the status signal input terminal 106. The alarm signal included in the output signal is input to the alarm input terminal 108. The transmission device 300 may extract the status signal and the alarm signal from the output signal and input them to the status signal input terminal 106 and the alarm input terminal 108. In another example, the control circuit 100 may receive the output signal, and the control circuit 100 may extract the status signal and the alarm signal from the output signal.

[0036] When a plurality of power conversion circuits 200 are connected to a common terminal of the control circuit 100, an identification code may be assigned to each of the power conversion circuits 200. When starting communication with any of the power conversion circuits 200, the control circuit 100 may transmit a signal including the identification code of the power conversion circuit 200. When each of the power conversion circuits 200 receives a signal including an identification code corresponding to itself, the control circuit 100 may operate according to the signal. The control circuit 100 may determine which of the power conversion circuits 200 the signal is from, based on identification information included in the signal output by the power conversion circuit 200.

[0037] The control circuit 100 may notify the start of communication to the power conversion circuit 200 by transmitting a clock signal. In another example, the control circuit 100 may notify the start of communication in a manner similar to that of I2C communication.

[0038] Fig. 2 is a diagram showing a configuration example of a portion of the power conversion circuit 200 and the transmission device 300. Fig. 2 shows a configuration for outputting and transmitting an output signal, and omits other configurations.

[0039] The power conversion circuit 200 includes an alarm signal generating unit 220 that generates an alarm signal, and a status signal generating unit 210 that generates a status signal. The status signal generating unit 210 generates a status signal having a pulse with a different amplitude from that of the alarm signal. By making the pulse amplitude of the alarm signal different from that of the status signal, the pulse of the alarm signal and the pulse of the status signal can be distinguished from each other. The transmission device 300 may determine whether each pulse is a pulse of the alarm signal or a pulse of the status signal based on the amplitude of each pulse included in the output signal.

[0040] The power conversion circuit 200 of this example further includes a power supply terminal 206, a power supply wiring 201, a reference voltage terminal 208, and a reference wiring 203. The reference wiring 203 is connected to the reference voltage terminal 208. A reference voltage GND is applied to the reference voltage terminal 208 and the reference wiring 203. The reference voltage GND is, for example, 0V. The power supply wiring 201 is connected to the power supply terminal 206. A first power supply voltage Vcc1 different from the reference voltage GND is applied to the power supply terminal 206 and the power supply wiring 201. The first power supply voltage Vcc1 may be a voltage higher than the reference voltage GND. As an example, the first power supply voltage Vcc1 is 15V. The alarm signal generating unit 220 and the status signal generating unit 210 are provided in parallel with each other between the power supply wiring 201 and the reference wiring 203.

[0041] The alarm signal generating unit 220 of this example switches between the reference voltage GND and the first power supply voltage Vcc1 to be applied to the output terminal 204. For example, the alarm signal generating unit 220 applies the reference voltage GND to the output terminal 204 during a period in which an alarm signal pulse should be generated, and applies the first power supply voltage Vcc1 to the output terminal 204 during other periods.

[0042] The alarm signal generating unit 220 of this example has a second switch 222. The second switch 222 is provided between the power supply wiring 201 and the reference wiring 203, and switches between the reference voltage GND and the first power supply voltage Vcc1 to be applied to the output terminal 204. When the second switch 222 is turned on, the reference voltage GND is applied to the output terminal 204, and when the second switch 222 is turned off, the first power supply voltage Vcc1 is applied to the output terminal 204. The second switch 222 is, for example, a MOS transistor. In this example, the source terminal of the second switch 222 is connected to the reference wiring 203, and the drain terminal is connected to the power supply wiring 201 and the output terminal 204. A second current source 221, which will be described later, may be provided between the drain terminal and the power supply wiring 201. An output resistor 230, which will be described later, may be provided between the drain terminal and the output terminal 204.

[0043] The power conversion circuit 200 may include a switch control unit 240 that controls the second switch 222. The switch control unit 240 may generate a gate signal to be applied to a gate terminal of the second switch 222. The switch control unit 240 may turn on the second switch 222 during a period in which a pulse of the alarm signal should be generated, and turn off the second switch 222 during other periods.

[0044] The alarm signal generating section 220 may further include a second current source 221. The second current source 221 is provided between the power supply wiring 201 and the second switch 222. The second current source 221 passes a current in a direction from the power supply wiring 201 to the second switch 222. A connection point between the second current source 221 and the second switch 222 is connected to the output terminal 204. An output resistor 230 may be provided between the connection point between the second current source 221 and the second switch 222 and the output terminal 204.

[0045] The status signal generating unit 210 of this example switches between applying to the output terminal 204 either the intermediate voltage Vm, which is closer to the first power supply voltage Vcc1 than the reference voltage GND, or the first power supply voltage Vcc1. For example, the status signal generating unit 210 applies the intermediate voltage Vm to the output terminal 204 during a period in which a status signal pulse should be generated, and applies the first power supply voltage Vcc1 to the output terminal 204 during other periods. The intermediate voltage Vm may be greater than half the first power supply voltage Vcc1. As an example, the intermediate voltage Vm is 10V.

[0046] The state signal generating section 210 of this example has a first switch 212 and an intermediate voltage generating section 213. The first switch 212 is provided between the reference wiring 203 and the power supply wiring 201. The intermediate voltage generating section 213 is provided between the first switch 212 and the reference wiring 203.

[0047] The intermediate voltage generating unit 213 generates an intermediate voltage Vm. The intermediate voltage generating unit 213 in this example has a Zener diode whose anode is connected to the reference wiring 203 and whose cathode is connected to the first switch 212. The intermediate voltage Vm is generated by the breakdown voltage of the Zener diode.

[0048] The first switch 212 switches whether the intermediate voltage Vm or the first power supply voltage Vcc1 is applied to the output terminal 204. When the first switch 212 is turned on, the intermediate voltage Vm is applied to the output terminal 204, and when the first switch 212 is turned off, the first power supply voltage Vcc1 is applied to the output terminal 204. The first switch 212 is, for example, a MOS transistor. In this example, the source terminal of the first switch 212 is connected to the intermediate voltage generating unit 213, and the drain terminal is connected to the power supply wiring 201 and the output terminal 204. A first current source 211, which will be described later, may be provided between the drain terminal and the power supply wiring 201. An output resistor 230 may be provided between the drain terminal and the output terminal 204.

[0049] The switch control unit 240 may control the first switch 212. The switch control unit 240 may generate a gate signal to be applied to a gate terminal of the first switch 212. The switch control unit 240 may turn on the first switch 212 in a period in which a pulse of the state signal should be generated, and turn off the first switch 212 in other periods.

[0050] The status signal generating unit 210 may further include a first current source 211. The first current source 211 is provided between the power supply wiring 201 and the first switch 212. The first current source 211 passes a current in a direction from the power supply wiring 201 to the first switch 212. A connection point between the first current source 211 and the first switch 212 is connected to the output terminal 204. An output resistor 230 may be provided between the connection point between the first current source 211 and the first switch 212 and the output terminal 204. The output resistor 230 in this example is provided in common to the alarm signal generating unit 220 and the status signal generating unit 210.

[0051] In this example, an output signal OS in which an alarm signal and a status signal are superimposed is applied to the output terminal 204. The output signal OS includes an alarm signal pulse and a status signal pulse. The alarm signal pulse and the status signal pulse have different amplitudes. In a period in which the alarm signal pulse and the status signal pulse overlap, the pulse with the larger amplitude (the alarm signal pulse in this example) is placed in the output signal OS.

[0052] The transmission device 300 of this example includes a first transmission section 310 and a second transmission section 320. Both the first transmission section 310 and the second transmission section 320 are connected to the output terminal 204 and receive the output signal OS.

[0053] The first transmission section 310 of this example generates a signal VM1 by extracting a component (a pulse in this example) from the output signal OS that has an amplitude greater than a first reference value. The second transmission section 320 of this example generates a signal VM2 by extracting a component from the output signal OS that has an amplitude greater than a second reference value. In this example, the first reference value in the first transmission section 310 is smaller than the second reference value in the second transmission section 320.

[0054] The amplitude of one of the pulses of the status signal and the alarm signal is greater than a first reference value and less than a second reference value. The pulse is extracted by the first transmission unit 310 but not by the second transmission unit 320. The amplitude of the other of the pulses of the status signal and the alarm signal is greater than the second reference value. The pulse is extracted by both the first transmission unit 310 and the second transmission unit 320.

[0055] 2, the amplitude of the pulse of the status signal is greater than the first reference value and less than the second reference value. Also, the amplitude of the pulse of the alarm signal is greater than the second reference value. In this case, the signal VM1 generated by the first transmission unit 310 includes both the pulse of the status signal and the pulse of the alarm signal. The signal VM2 generated by the second transmission unit 320 does not include the pulse of the status signal, but includes the pulse of the alarm signal.

[0056] 2 inputs a signal VM2 to the alarm input terminal 108 of the control circuit 100. When the control circuit 100 detects that the signal VM2 includes a pulse of an alarm signal, the control circuit 100 may input a stop signal to the power conversion circuit 200 to stop the power conversion operation of the power conversion circuit 200. When the power conversion circuit 200 performs power conversion using a switching element, the control circuit 100 may stop the switching operation of the switching element.

[0057] When the stop signal is input, the power conversion circuit 200 may further stop outputting the status signal. In another example, the power conversion circuit 200 may continue to output the status signal even after the stop signal is input. In this way, the control circuit 100 can detect the temperature, voltage, or current of the power conversion circuit 200 even after the power conversion operation of the power conversion circuit 200 is stopped. When the power conversion operation of the power conversion circuit 200 is stopped based on an alarm signal indicating that the power conversion circuit 200 is in an overheated state, the control circuit 100 may resume the power conversion operation of the power conversion circuit 200 when the temperature of the power conversion circuit 200 becomes equal to or lower than a set value. When the power conversion operation of the power conversion circuit 200 is stopped based on an alarm signal indicating that the power conversion circuit 200 is in an overvoltage or overcurrent state, the control circuit 100 may resume the power conversion operation of the power conversion circuit 200 when the voltage or current of the power conversion circuit 200 becomes equal to or lower than a set value.

[0058] 2 inputs a signal VM1 to a status signal input terminal 106 of the control circuit 100. The control circuit 100 detects a status signal of the power conversion circuit 200 based on a pulse of the signal VM1. In this example, the pulse of the signal VM1 during a period when a pulse is present in the signal VM2 is not a pulse of the status signal. The control circuit 100 does not need to use the pulse of the signal VM1 during a period when a pulse is present in the signal VM2 to detect the status signal.

[0059] According to this example, the alarm signal and the status signal can be output from the common output terminal 204. Furthermore, the alarm signal and the status signal can be extracted in the transmission device 300. In a period in which the pulses of the alarm signal and the status signal overlap, the pulse of the alarm signal can be detected with priority. This allows the alarm signal pulse and the status signal pulse to be quickly identified, and an abnormality in the power conversion circuit 200 can be quickly detected.

[0060] The first transmission section 310 of this example has a photocoupler. The first transmission section 310 has a first light emitting element 311 such as a light emitting diode, and a first light receiving element 312 such as a phototransistor. The second transmission section 320 of this example has a photocoupler. The second transmission section 320 has a second light emitting element 321 such as a light emitting diode, and a second light receiving element 322 such as a phototransistor.

[0061] The transmission device 300 of this example further includes a first power supply voltage generating unit 330 that generates a first power supply voltage Vcc1 based on a reference voltage GND, and a second power supply voltage generating unit 340 that generates a second power supply voltage Vcc2 based on the reference voltage GND. The second power supply voltage generating unit 340 of this example is a power supply that generates a second power supply voltage Vcc2 that is higher than the reference voltage.

[0062] A first power supply voltage Vcc1 is applied to the anode of the first light emitting element 311, and an output signal OS is applied to the cathode. The first light emitting element 311 emits light when the voltage between the anode and cathode reaches a reference value or higher. The first light receiving element 312 is turned on in response to the emission of light by the first light emitting element 311, and sets the voltage of the signal VM1 to an L level (e.g., 0 V). When the first light receiving element 312 is turned off, the voltage of the signal VM1 becomes a predetermined H level that is higher than 0 V.

[0063] The second light-emitting element 321 has an anode to which a second power supply voltage Vcc2 is applied, and a cathode to which an output signal OS is applied. The second light-emitting element 321 emits light when the voltage between the anode and cathode reaches a reference value or higher. The second light-receiving element 322 is turned on in response to the emission of light by the second light-emitting element 321, and sets the voltage of the signal VM2 to an L level (e.g., 0 V). When the second light-receiving element 322 is turned off, the voltage of the signal VM2 becomes a predetermined H level that is higher than 0 V.

[0064] FIG. 3 is a timing chart showing an example of the output signal OS, the signal VM1, and the signal VM2. The output signal OS in this example includes a pulse of a status signal and a pulse of an alarm signal. The pulse of the status signal has an amplitude from the first power supply voltage Vcc1 to the intermediate voltage Vm. The pulse of the alarm signal has an amplitude from the first power supply voltage Vcc1 to the reference voltage GND. The second power supply voltage Vcc2 is a voltage between the reference voltage GND and the intermediate voltage Vm. As an example, the first power supply voltage Vcc1 is 15V, the intermediate voltage Vm is 10V, the second power supply voltage Vcc2 is 5V, and the reference voltage GND is 0V.

[0065] The first transmission unit 310 shown in FIG. 2 outputs a signal VM1 according to the difference between the first power supply voltage Vcc1 and the voltage of the output signal OS. When the voltage difference is greater than a first threshold voltage that causes the first light emitting element 311 to emit light, a pulse is placed in the signal VM1. The first threshold voltage in this example is smaller than the difference between the first power supply voltage Vcc1 and the intermediate voltage Vm. The first threshold voltage is also smaller than the difference between the first power supply voltage Vcc1 and the reference voltage GND. As a result, a pulse is placed in the signal VM1 corresponding to both the pulse of the status signal and the pulse of the alarm signal. The control circuit 100 can detect the status signal based on the signal VM1.

[0066] The second transmission unit 320 shown in FIG. 2 outputs a signal VM2 according to the difference between the second power supply voltage Vcc2 and the voltage of the output signal OS. When the voltage of the difference is greater than a second threshold voltage that causes the second light-emitting element 321 to emit light, a pulse is placed in the signal VM2. The second threshold voltage in this example is smaller than the difference between the second power supply voltage Vcc2 and the reference voltage GND. As a result, a pulse is placed in the signal VM2 corresponding to the pulse of the alarm signal. Also, the L-level intermediate voltage Vm in the pulse of the status signal is higher than the second power supply voltage Vcc2. In this case, a reverse voltage is applied to the second light-emitting element 321, and it does not emit light. Therefore, a pulse corresponding to the pulse of the status signal is not placed in the signal VM2. The control circuit 100 can detect the alarm signal based on the signal VM2.

[0067] The pulse widths tT1 and tT2 of the status signal may indicate a value of the temperature, voltage, or current of the power conversion circuit 200. For example, a larger pulse width indicates a higher temperature, voltage, or current. Furthermore, each pulse width tA1, tA2, and tA3 of the alarm signal corresponds to an abnormal state occurring in the power conversion circuit 200. When multiple types of abnormalities occur in the power conversion circuit 200, the power conversion circuit 200 may generate an output signal having multiple pulses corresponding to multiple abnormal states as shown in FIG. 3.

[0068] 4 is a diagram showing another example of the configuration of the transmission device 300. The transmission device 300 of this example includes a step-down circuit 342 that functions as a second power supply voltage generating unit 340. The other configuration is similar to the example shown in FIG.

[0069] The step-down circuit 342 generates a second power supply voltage Vcc2 by stepping down the first power supply voltage Vcc1 with the first power supply voltage Vcc1 as a reference. The step-down circuit 342 may have a Zener diode having a cathode connected to the power supply terminal 206 and an anode connected to the reference voltage terminal 208. The anode of the Zener diode is connected to the anode of the second light-emitting element 321. The second power supply voltage Vcc2, which is lower than the first power supply voltage Vcc1, is generated by the breakdown voltage of the Zener diode.

[0070] 3, the second power supply voltage Vcc2 is a voltage between the intermediate voltage Vm and the reference voltage GND. In other words, the voltage (Vcc1-Vcc2) stepped down by the step-down circuit 342 is greater than the difference (Vcc1-Vm) between the first power supply voltage Vcc1 and the intermediate voltage Vm.

[0071] The transmission device 300 may further include a resistor 344. The resistor 344 is disposed between the connection point of the step-down circuit 342 and the second light-emitting element 321 and the reference voltage terminal 208. In this example, as in the examples of Figs. 1 to 3, the pulse of the alarm signal and the pulse of the status signal can be quickly distinguished. The step-down circuit 342 may be a circuit other than a Zener diode. For example, a regulator circuit may be used as the step-down circuit 342.

[0072] 5 is a diagram showing another configuration example of the power conversion circuit 200. In this example, the intermediate voltage generating unit 213 is provided in the alarm signal generating unit 220, not in the status signal generating unit 210. The other configuration is similar to the example shown in FIG. 2. The intermediate voltage generating unit 213 in this example is provided between the second switch 222 and the reference wiring 203. In this example, the anode of the intermediate voltage generating unit 213 is connected to the reference wiring 203, and the cathode is connected to the source of the second switch 222.

[0073] In this example, the amplitude of the pulse of the alarm signal is smaller than the amplitude of the pulse of the status signal. In this example as well, the first transmission unit 310 generates a signal VM1 by extracting a component (pulse in this example) from the output signal OS that has an amplitude larger than a first reference value. The second transmission unit 320 generates a signal VM2 by extracting a component from the output signal OS that has an amplitude larger than a second reference value. The first reference value in the first transmission unit 310 is smaller than the second reference value in the second transmission unit 320.

[0074] In this example, the amplitude of the pulse of the alarm signal is greater than the first reference value and less than the second reference value. Also, the amplitude of the pulse of the status signal is greater than the second reference value. In this case, the signal VM2 generated by the second transmission unit 320 includes both the pulse of the status signal and the pulse of the alarm signal. The signal VM1 generated by the first transmission unit 310 includes the pulse of the status signal, but does not include the pulse of the alarm signal.

[0075] Fig. 6 is a timing chart showing an example of the output signal OS, the signal VM1, and the signal VM2 in the configuration shown in Fig. 5. In this example, the pulse of the status signal has an amplitude ranging from the first power supply voltage Vcc1 to the reference voltage GND. The pulse of the alarm signal has an amplitude ranging from the first power supply voltage Vcc2 to the intermediate voltage Vm.

[0076] In this example, pulses are placed in the signal VM1 corresponding to both the pulses of the status signal and the pulses of the alarm signal, and pulses are placed in the signal VM2 corresponding to the pulses of the status signal.

[0077] The control circuit 100 can detect the state of the power conversion circuit 200 based on the pulse widths tT1 and tT2 of the signal VM2. The control circuit 100 detects an alarm signal of the power conversion circuit 200 based on the pulse of the signal VM1. In this example, the pulse of the signal VM1 during the period when a pulse is present in the signal VM2 is not a pulse of the alarm signal. The control circuit 100 does not need to use the pulse of the signal VM1 during the period when a pulse is present in the signal VM2 to detect the alarm signal.

[0078] According to this example, the alarm signal and the status signal can be output from the common output terminal 204. Also, the alarm signal and the status signal can be extracted in the transmission device 300. In a period in which the pulses of the alarm signal and the status signal overlap, the pulse of the status signal can be detected preferentially. This makes it easier to detect the temperature, voltage, or current of the power conversion circuit 200.

[0079] Fig. 7 is a diagram showing another example of the configuration of the power conversion circuit 200. The power conversion circuit 200 of this example further includes an amplitude switching unit 214 in addition to the configuration shown in Fig. 2 or Fig. 5. The intermediate voltage generating unit 213 may be provided inside the amplitude switching unit 214. Also, in Fig. 7, the switch control unit 240 is omitted. The other configuration is similar to the example of Fig. 2 or Fig. 5.

[0080] The amplitude switching unit 214 switches whether the power conversion circuit 200 functions as the example described in Fig. 2 or the example described in Fig. 5. That is, the amplitude switching unit 214 switches which of the alarm signal and the status signal has an amplitude larger than the other. The amplitude switching unit 214 may switch which of the alarm signal and the status signal has an amplitude larger than the second reference value and which of the alarm signal and the status signal has an amplitude larger than the first reference value and smaller than the second reference value.

[0081] The amplitude switching section 214 may switch whether the intermediate voltage generating section 213 is connected to the alarm signal generating section 220 as shown in Fig. 5 or to the status signal generating section 210 as shown in Fig. 2. The amplitude switching section 214 may have a changeover switch that switches whether the intermediate voltage generating section 213 is connected to the alarm signal generating section 220 or to the status signal generating section 210.

[0082] The amplitude switching section 214 may have a first path having the intermediate voltage generating section 213 and a second path not having the intermediate voltage generating section 213. The changeover switch may select either the first switch 212 or the second switch 222 to connect to the reference wiring 203 via the first path, and may select either the first switch 212 or the second switch 222 to connect to the reference wiring 203 via the second path.

[0083] According to this example, the power conversion circuit 200 can function as either the example in Fig. 2 or the example in Fig. 5. Which example the power conversion circuit 200 functions as may be set by a user of the power conversion circuit 200, may be set by a manufacturer of the power conversion circuit 200, or may be controlled by the control circuit 100 or another device. Information regarding which example the power conversion circuit 200 is functioning as may be notified to the control circuit 100. The amplitude switching unit 214 may notify the control circuit 100 of the information.

[0084] The control circuit 100 may determine whether a pulse of the signal VM2 is a pulse of an alarm signal or a pulse of a status signal based on which example the power conversion circuit 200 is functioning as. The control circuit 100 may determine whether a pulse of the signal VM1 that does not overlap with a pulse of the signal VM2 is a pulse of an alarm signal or a pulse of a status signal based on which example the power conversion circuit 200 is functioning as.

[0085] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention. [Explanation of symbols]

[0086] 10 circuit device, 100 control circuit, 102 control output terminal, 106 status signal input terminal, 108 alarm input terminal, 200 power conversion circuit, 201 power supply wiring, 202 control terminal, 203 reference wiring, 204 output terminal, 206 power supply terminal, 208 reference voltage terminal, 210 status signal generating section, 211 first current source, 212 first switch, 213 intermediate voltage generating section, 214 amplitude switching a first current source, a second current source, a first switch, a first output resistor, a first light receiving element, a second light receiving element, a first power supply voltage generating unit, a second power supply voltage generating unit, a first power supply voltage generating unit, a second power supply voltage generating unit, a second current source, a second switch, a first output resistor, a first output resistor, a second output resistor, a first output resistor, a second output resistor,

Claims

1. A circuit device including a power conversion circuit and a transmission device that transmits a signal from the power conversion circuit, The power conversion circuit includes: an alarm signal generating unit that generates an alarm signal indicating whether the power conversion circuit is in a preset state; a status signal generating unit that generates a status signal having an amplitude different from that of the alarm signal and indicating a status of the power conversion circuit; A circuit device having the above configuration.

2. The power conversion circuit further includes an output terminal for outputting an output signal in which the alarm signal and the status signal are superimposed. The circuit device according to claim 1 .

3. the alarm signal generating unit switches between a reference voltage and a first power supply voltage different from the reference voltage to be applied to the output terminal; The state signal generating unit switches between applying to the output terminal either an intermediate voltage that is closer to the first power supply voltage than the reference voltage or the first power supply voltage. The circuit device according to claim 2 .

4. The power conversion circuit includes: a reference wiring to which the reference voltage is applied; a power supply line to which the first power supply voltage is applied; Further comprising: The state signal generating unit is a first switch provided between the reference wiring and the power supply wiring; an intermediate voltage generating unit that is provided between the first switch and the reference wiring and that generates the intermediate voltage; 4. The circuit arrangement according to claim 3, further comprising:

5. The alarm signal generating unit has a second switch that switches whether the reference voltage or the first power supply voltage is to be applied to the output terminal. The circuit arrangement according to claim 4.

6. The transmission device includes: a first transmission section that transmits a component of the output signal having an amplitude larger than a first reference value; a second transmission section that transmits a component of the output signal having an amplitude larger than a second reference value; having The first reference value is smaller than the second reference value. The circuit device according to claim 2 .

7. the amplitude of the status signal is greater than the first reference value and less than the second reference value; The amplitude of the alarm signal is greater than the second reference value. The circuit arrangement according to claim 6.

8. the amplitude of the status signal is greater than the second reference value; The amplitude of the alarm signal is greater than the first reference value and less than the second reference value. The circuit arrangement according to claim 6.

9. The power conversion circuit further includes an amplitude switching unit that switches which of the alarm signal and the status signal has an amplitude greater than the second reference value and which of the alarm signal and the status signal has an amplitude greater than the first reference value and less than the second reference value. The circuit arrangement according to claim 6.

10. The transmission device includes: a second power supply voltage generating unit that generates a second power supply voltage between the reference voltage and the intermediate voltage; a first transmission unit that outputs a signal corresponding to a difference between the first power supply voltage and a voltage at the output terminal; a second transmission section that outputs a signal corresponding to a difference between the second power supply voltage and a voltage at the output terminal; 4. The circuit arrangement according to claim 3, further comprising:

11. The second power supply voltage generating unit is a power supply that generates the second power supply voltage higher than the reference voltage based on the reference voltage. The circuit arrangement according to claim 10.

12. The second power supply voltage generating unit is a step-down circuit that generates the second power supply voltage by stepping down the first power supply voltage based on the first power supply voltage. The circuit arrangement according to claim 10.

13. A stop signal for stopping a power conversion operation is input to the power conversion circuit, The power conversion circuit continues to output the state signal even after the stop signal is input. The circuit device according to claim 1 .

14. The state signal is a signal indicating any one of a temperature, a current, and a voltage state of the power conversion circuit, and the state signal generating unit generates the state signal. A circuit arrangement according to any one of claims 1 to 13.

15. 1. A power conversion circuit, comprising: an alarm signal generating unit that generates an alarm signal indicating whether the power conversion circuit is in a preset state; a status signal generating unit that generates a status signal having an amplitude different from that of the alarm signal and indicating a status of the power conversion circuit; A power conversion circuit comprising:

16. The alarm signal is output from an output terminal that outputs an output signal obtained by superimposing the alarm signal and the status signal.

16. The power conversion circuit of claim 15.

17. the alarm signal generating unit switches between a reference voltage and a first power supply voltage different from the reference voltage to be applied to the output terminal; The state signal generating unit switches between applying to the output terminal either an intermediate voltage that is closer to the first power supply voltage than the reference voltage or the first power supply voltage.

17. The power conversion circuit of claim 16.

18. a reference wiring to which the reference voltage is applied; a power supply line to which the first power supply voltage is applied; Further comprising: The state signal generating unit is a first switch provided between the reference wiring and the power supply wiring; an intermediate voltage generating unit that is provided between the first switch and the reference wiring and that generates the intermediate voltage; 20. The power conversion circuit of claim 17, comprising:

19. The alarm signal generating unit has a second switch that switches whether the reference voltage or the first power supply voltage is to be applied to the output terminal.

20. The power conversion circuit of claim 18.

20. The alarm signal and the status signal are further provided with an amplitude switching unit that switches which of the alarm signal and the status signal has an amplitude larger than the other.

17. The power conversion circuit of claim 16.

21. The state signal is a signal indicating any one of a temperature, a current, and a voltage state of the power conversion circuit, and the state signal generating unit generates the state signal.

21. A power conversion circuit according to any one of claims 15 to 20.

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