# US 12,184,054 B2 · Overcurrent protection circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,054 B2 - Document ID: US12184054B2 - Status: Granted - Kind: B2 - Application number: 18/484,721 - Filed: 2023-10-11 - Published: 2024-02-01 - Granted: 2024-12-31 - Earliest claimed: 2016-04-28 - Assignees: Rohm Co., Ltd. - Applicants: Rohm Co., Ltd. - Inventors: Toru Takuma; Naoki Takahashi; Shuntaro Takahashi - Web page: https://patentgrep.com/patent/US12184054B2 ## CPC - H02H 1/0007: {concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445)} - H03K 17/0822: {in field-effect transistor switches} - B60R 16/02: electric {constitutive elements} - B60R 16/03: for supply of electrical power to vehicle subsystems {or for (circuit arrangements for charging batteries H02J7/00)} - H02H 3/087: for DC applications - H02H 3/093: with timing means {(in general H02H3/027; thermal delay H02H3/085; timing means for undervoltage protection H02H3/247)} - H02H 7/20: for electronic equipment (for converters H02H7/10; for electric measuring instruments G01R1/36; for DC voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08) - H02H 7/205: {for controlled semi-conductors which are not included in a specific circuit arrangement} - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - 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) - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR ## Abstract In order both to accommodate instantaneous current as well as overcurrent protection in accordance with the load, an overcurrent protection circuit has: a threshold value generation unit that, in accordance with a threshold value control signal, switches between setting an overcurrent detection threshold value to a first set value (∝ Iref) and a second set value (∝ Iset) lower than the first set value; an overcurrent detection unit that compares a sense signal in accordance with the current being monitored and the overcurrent detection value and generates an overcurrent protection signal; a reference value generation unit that generates a reference value (∝ Iset) in accordance with the seconds set value; a comparison unit that compares the sense signal and the reference value, and generates a comparison signal; and a threshold value control unit that monitors the comparison signal, and generates a threshold value control signal. ## Claims ### Claim 1 A semiconductor integrated circuit device comprising: an overcurrent protection circuit configured to compare a sense signal and a first voltage at a first timing, to compare the sense signal and a second voltage at a second timing, and to generate an overcurrent protection signal in accordance with the comparison results, wherein the second voltage is externally adjustable, and the semiconductor device further comprises a terminal configured to output an output signal to a control unit, the output signal resulting from an exclusively switched signal. ### Claim 2 (depends on 1) The semiconductor integrated circuit device according to claim 1, wherein the overcurrent protection circuit includes: an overcurrent detector configured to compare the sense signal in accordance with a monitored current with an overcurrent detection threshold and generate the overcurrent protection signal, the overcurrent detection threshold is switched to either the first voltage or the second voltage in accordance with a comparison signal; and a comparison section configured to compare the sense signal with a reference value in accordance with the first voltage and generate the comparison signal, wherein the monitored current is an output current flowing through a high-side switch. ### Claim 3 (depends on 1) The semiconductor integrated circuit device according to claim 1, wherein the overcurrent protection circuit includes: an overcurrent detector configured to compare the sense signal in accordance with a monitored current with an overcurrent detection threshold and generate the overcurrent protection signal, the overcurrent detection threshold is switched to either the first voltage or the second voltage in accordance with a comparison signal; and a comparison section configured to compare the sense signal with a reference value in accordance with the first voltage and generate the comparison signal, wherein: the monitored current includes a first monitored current and a second monitored current, the sense signal includes a first sense signal and a second sense signal, the overcurrent detection threshold includes a first overcurrent detection threshold and a second overcurrent detection threshold, the overcurrent protection signal includes a first overcurrent protection signal and a second overcurrent protection signal, the reference value includes a first reference value and a second reference value, the comparison signal includes a first comparison signal and a second comparison signal, the overcurrent detector includes a first overcurrent detector and a second overcurrent detector, and the comparison section includes a first comparison section and a second comparison section, wherein the first monitored current is a first output current flowing through a first high- side switch, and the second monitored current is a second output current flowing through a second high-side switch. ### Claim 4 (depends on 3) The semiconductor integrated circuit device according to claim 3, wherein the overcurrent protection circuit further includes: a first threshold generator configured to switch, in accordance with a first threshold control signal, whether the first overcurrent detection threshold should be a first set value or a second set value which is lower than the first set value; a second threshold generator configured to switch, in accordance with a second threshold control signal, whether the second overcurrent detection threshold should be a third set value or a fourth set value which is lower than the third set value; a first reference value generator configured to generate the first reference value in accordance with the second set value; a second reference value generator configured to generate the second reference value in accordance with the fourth set value; and a threshold controller configured to monitor both the first comparison signal and the second comparison signal and to generate the first threshold control signal and the second threshold control signal, wherein: the first overcurrent detector is configured to compare the first sense signal in accordance with the first monitored current with the first overcurrent detection threshold and to generate the first overcurrent protection signal, the second overcurrent detector is configured to compare the second sense signal in accordance with the second monitored current with the second overcurrent detection threshold and to generate the second overcurrent protection signal, the first comparison section is configured to compare the first sense signal with the first reference value and to generate the first comparison signal, and the second comparison section is configured to compare the second sense signal with the second reference value and to generate the second comparison signal. ### Claim 5 (depends on 4) The semiconductor integrated circuit device according to claim 4, wherein the threshold controller includes: an external terminal for externally connecting a capacitor, a comparator configured to compare a charge voltage which appears at the external terminal with a predetermined reference voltage and to generate an internal signal, a first flip-flop configured to generate the first threshold control signal in accordance with the internal signal and the first comparison signal, a second flip-flop configured to generate the second threshold control signal in accordance with the internal signal and the second comparison signal, a discharge controller configured to perform discharge control of the capacitor in accordance with the internal signal, and a charge controller configured to perform charge control of the capacitor in accordance with both the first comparison signal and the second comparison signal. ### Claim 6 (depends on 5) The semiconductor integrated circuit device according to claim 5, wherein the overcurrent protection circuit is configured such that: the discharge controller accepts input of not only the internal signal but also the first comparison signal, the second comparison signal, the first threshold control signal, and the second threshold control signal, and when, after a logic-level change occurs in one of the first comparison signal and the second comparison signal and a charging operation of the capacitor is started, a logic-level change occurs in another of the first comparison signal and the second comparison signal before the charge voltage becomes higher than the reference voltage, the capacitor is discharged. ### Claim 7 (depends on 6) The semiconductor integrated circuit device according to claim 6, wherein the threshold controller further includes: a first delay section configured to give a delay to the first comparison signal and to generate a first delay signal, and a second delay section configured to give a delay to the second comparison signal and to generate a second delay signal, and the first delay signal and the second delay signal, instead of the first comparison signal and the second comparison signal, are inputted to the first flip-flop and the second flip-flop, respectively. ### Claim 8 (depends on 4) The semiconductor integrated circuit device according to claim 4, wherein each of the first set value and the third set value is a fixed value, and each of the second set value and the fourth set value is a variable value. ### Claim 9 (depends on 1) The semiconductor integrated circuit device according to claim 1 comprising: a first high-side switch configured to switch a first current path, through which a first output current flows, between a conducting state and a cutoff state; a second high-side switch configured to switch a second current path, through which a second output current flows, between a conducting state and a cutoff state; a first output current monitor configured to generate a first sense signal in accordance with the first output current; a second output current monitor configured to generate a second sense signal in accordance with the second output current; a first gate controller configured to generate a first driving signal for the first high- side switch in accordance with a first control signal; a second gate controller configured to generate a second driving signal for the second high-side switch in accordance with a second control signal; wherein the overcurrent protection circuit is configured to monitor the first sense signal and the second sense signal, wherein the first gate controller and the second gate controller have functions of forcibly turning off the first high-side switch and the second high-side switch in accordance with a first overcurrent protection signal and a second overcurrent protection signal, respectively. ### Claim 10 (depends on 9) The semiconductor integrated circuit device according to claim 9, further comprising, integrated therein: a first signal output section configured to generate one of a detection result of the first output current and an abnormality flag as a first status notification signal; a second signal output section configured to generate one of a detection result of the second output current and an abnormality flag as a second status notification signal; and a multiplexer configured to selectively output one of the first status notification signal and the second status notification signal to outside the device. ### Claim 11 (depends on 9) An electronic apparatus comprising: the semiconductor integrated circuit device according to claim 9; a first load connected to the first high-side switch; and a second load connected to the second high-side switch. ### Claim 12 (depends on 11) The electronic apparatus according to claim 11, wherein each of the first load and the second load is a bulb lamp, a relay coil, a solenoid, a light emitting diode, or a motor. ### Claim 13 (depends on 11) A vehicle comprising the electronic apparatus according to claim 11. ### Claim 14 (depends on 1) The semiconductor integrated circuit device according to claim 1, wherein the first timing is a start-up timing of the semiconductor device. ### Claim 15 (depends on 14) The semiconductor integrated circuit device according to claim 14, wherein the first voltage is higher than the second voltage. ### Claim 16 (depends on 15) The semiconductor integrated circuit device according to claim 15, wherein the first voltage is based on a internal set value.