# US 10,374,592 B2 · Semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,592 B2 - Document ID: US10374592B2 - Status: Granted - Kind: B2 - Application number: 15/207,493 - Filed: 2016-07-11 - Published: 2016-11-03 - Granted: 2019-08-06 - Earliest claimed: 2014-07-14 - Assignees: Fuji Electric Co., Ltd. - Applicants: Fuji Electric Co., Ltd. - Inventors: Masashi Akahane - Web page: https://patentgrep.com/patent/US10374592B2 ## CPC - H03K 17/08128: {in composite switches} - H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters - H03K 5/08: by limiting; by thresholding; by slicing, i.e. combined limiting and thresholding (H03K5/07 takes precedence; comparing one pulse with another H03K5/22; providing a determined threshold for switching H03K17/30) - H03K 17/165: {by feedback from the output circuit to the control circuit} - H03K 17/18: Modifications for indicating state of switch - H03K 19/017509: {Interface arrangements} - H10D 84/811: {Combinations of field-effect devices and one or more diodes, capacitors or resistors} - H10D 89/611: {using diodes as protective elements} - H03K 2217/0027: Measuring means of, e.g. currents through or voltages across the switch - H10D 8/25: Zener diodes - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract A semiconductor device includes a first circuit operating with a first potential as a reference potential and a second circuit operating with a second potential different from the first potential as a reference potential, able to reliably detect that a negative voltage is applied to the first circuit. The first circuit includes a current source. The current source supplies a current to the low side circuit, and changes the current in response to whether or not the first potential becomes a negative voltage with respect to the second potential. Also, the second circuit includes a negative voltage detection circuit. The negative voltage detection circuit monitors a change in the current supplied from the current source and detects that a negative voltage is applied to the high side circuit. ## Claims ### Claim 1 A semiconductor device, comprising: a first circuit configured to operate with a first voltage as a reference potential; a second circuit configured to operate with a second voltage different from the first voltage as a reference voltage; a current source in the first circuit configured to supply a current to the second circuit and to change the current based on whether the first voltage becomes a negative voltage with respect to the second voltage; and a negative voltage detection circuit in the second circuit and configured to monitor a change in the current supplied from the current source and configured to detect that the negative voltage is applied to the first circuit, wherein the current source is configured to supply a predetermined current toward the second circuit when the first voltage is higher than the second voltage, and configured to reverse a direction of the current to be supplied to the second circuit when the first voltage is lower than the second voltage. ### Claim 2 (depends on 1) A semiconductor device according to claim 1, comprising: a first circuit configured to operate with a first voltage as a reference potential; a second circuit configured to operate with a second voltage different from the first voltage as a reference voltage; a current source in the first circuit configured to supply a current to the second circuit and to change the current based on whether the first voltage becomes a negative voltage with respect to the second voltage; and a negative voltage detection circuit in the second circuit and configured to monitor a change in the current supplied from the current source and configured to detect that the negative voltage is applied to the first circuit, wherein the negative voltage detection circuit, when the direction of the current supplied from the current source changes, detects the change as the negative voltage being applied to the first circuit. ### Claim 3 A semiconductor device, comprising: a first circuit configured to operate with a first voltage as a reference potential; a second circuit configured to operate with a second voltage different from the first voltage as a reference voltage; a current source in the first circuit configured to supply a current to the second circuit and to change the current based on whether the first voltage becomes a negative voltage with respect to the second voltage; and a negative voltage detection circuit in the second circuit and configured to monitor a change in the current supplied from the current source and configured to detect that the negative voltage is applied to the first circuit, wherein the first circuit is a high side circuit which controls an on/off operation of a semiconductor switching element with a higher voltage than a ground potential received at a first terminal of the semiconductor switching element, and which has an intermediate potential as the reference potential, the intermediate potential being the potential of a second terminal of the semiconductor switching element, while the second circuit is a low side circuit which operates with the ground potential as the reference voltage. ### Claim 4 (depends on 3) The semiconductor device according to claim 3, wherein the first circuit is configured to drive a high side driver which controls an operation of the semiconductor switching element which operates on/off with the intermediate potential as a reference. ### Claim 5 (depends on 4) The semiconductor device according to claim 4, wherein the high side driver is part of the first circuit. ### Claim 6 (depends on 1) The semiconductor device according to claim 1, wherein the first circuit turns on/off a current flowing through a inductor via a semiconductor switching element and controls an on/off operation of the semiconductor switching element in a converter which generates power to be supplied to a load via the inductor. ### Claim 7 A semiconductor device, comprising: a first circuit configured to operate with a first voltage as a reference potential; a second circuit configured to operate with a second voltage different from the first voltage as a reference voltage; a current source in the first circuit configured to supply a current to the second circuit and to change the current based on whether the first voltage becomes a negative voltage with respect to the second voltage; and a negative voltage detection circuit in the second circuit and configured to monitor a change in the current supplied from the current source and configured to detect that the negative voltage is applied to the first circuit, wherein the first and second circuits are integrated into a high voltage compatible integrated circuit which complementarily controls an on/off drive of first and second semiconductor switching elements which are connected in series to form a half bridge circuit and make up a power source portion which supplies power to a load from a midpoint of the half bridge circuit, the potential of the midpoint being the reference potential. ### Claim 8 (depends on 7) The semiconductor device according to claim 7, wherein the first circuit is configured to drive a high side driver which controls the operation of the first switching element which operates on/off with an intermediate potential as the reference potential, the intermediate potential being the potential of the midpoint of the half bridge circuit, and wherein the second circuit drives a low side driver which controls the operation of the second semiconductor switching element which operates on/off with the reference voltage as a reference. ### Claim 9 (depends on 8) The semiconductor device according to claim 8, wherein the high side driver is part of the first circuit. ### Claim 10 (depends on 1) The semiconductor device according to claim 1, wherein the current source includes a high voltage MOS-FET including a source terminal connected to a predetermined voltage power source, the high voltage MOS-FET configured to operate based on receiving a predetermined bias voltage at the gate and configured to output a constant current from a drain terminal. ### Claim 11 A semiconductor device, comprising: a first circuit configured to operate with a first voltage as a reference potential; a second circuit configured to operate with a second voltage different from the first voltage as a reference voltage; a current source in the first circuit configured to supply a current to the second circuit and to change the current based on whether the first voltage becomes a negative voltage with respect to the second voltage; and a negative voltage detection circuit in the second circuit and configured to monitor a change in the current supplied from the current source and configured to detect that the negative voltage is applied to the first circuit, wherein the negative voltage detection circuit includes a current-voltage conversion circuit configured to convert the current supplied from the current source to an output voltage and a comparator which compares the output voltage of the current-voltage conversion circuit with a predetermined reference voltage and detects a negative voltage applied to the first circuit. ### Claim 12 (depends on 11) The semiconductor device according to claim 11, wherein the current-voltage conversion circuit includes a resistance element configured to convert the current supplied from the current source to the output voltage and a clamp circuit connected in parallel to the resistance element and configured to clamp a voltage applied to the resistance element. ### Claim 13 (depends on 12) The semiconductor device according to claim 12, wherein the clamp circuit includes a Zener diode. ### Claim 14 (depends on 12) The semiconductor device according to claim 12, wherein the clamp circuit includes a plurality of Zener diodes connected in series and a diode connected in inverse parallel to the series circuit of the Zener diodes. ### Claim 15 (depends on 11) The semiconductor device according to claim 11, wherein the current-voltage conversion circuit includes a current mirror circuit configured to generate a current proportional to the current supplied from the current source, a resistance element configured to convert a current output from the current mirror circuit to an output voltage, and a clamp circuit connected in parallel to the current mirror circuit and configured to clamp a voltage applied to the current mirror circuit. ### Claim 16 (depends on 15) The semiconductor device according to claim 15, wherein the clamp circuit includes a Zener diode. ### Claim 17 (depends on 15) The semiconductor device according to claim 15, wherein the clamp circuit includes a plurality of Zener diodes connected in series and a diode connected in inverse parallel to the series circuit of the Zener diodes. ### Claim 18 (depends on 1) The semiconductor device according to claim 1, wherein the negative voltage detection circuit is configured to output, based on detecting a negative voltage applied to the first circuit, a stop signal which stops the drive of a semiconductor switching element which is turned on and off by the first circuit. ### Claim 19 A semiconductor device, comprising: a first circuit configured to operate with a first voltage as a reference potential; a second circuit configured to operate with a second voltage different from the first voltage as a reference voltage; a current source in the first circuit configured to supply a current to the second circuit and to change the current based on whether the first voltage becomes a negative voltage with respect to the second voltage; and a negative voltage detection circuit in the second circuit and configured to monitor a change in the current supplied from the current source and configured to detect that the negative voltage is applied to the first circuit, wherein the second circuit includes an alarm circuit configured to output, based on a signal being output from the negative voltage detection circuit for a predetermined time, an alarm signal indicating an anomaly of a semiconductor having a driver controlled by the first circuit.