# US 2017/0288538 A1 · Circuit device, switching regulator, and electronic apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0288538 A1 - Document ID: US20170288538A1 - Status: Published application - Kind: A1 - Application number: 15/458,351 - Filed: 2017-03-14 - Published: 2017-10-05 - Earliest claimed: 2016-03-30 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Atsushi YAMADA; Isamu MORIYA; Isao SHISHIKURA - Web page: https://patentgrep.com/patent/US20170288538A1 ## CPC - H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 3/158: including plural semiconductor devices as final control devices for a single load - 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) ## Abstract A circuit device includes: a comparator that outputs an output signal that is activated when a potential of an input terminal is lower than a determination level; a switch circuit that is electrically connected between an output node connected to a switching element that enters a conduction state or a non-conduction state according to a drive signal and the input terminal of the comparator, and is in a non-conduction state when the switching element is in a conduction state; and a control circuit that controls a level of the drive signal such that the switching element will not enter a conduction state again based on a period during which or the number of times the output signal of the comparator is activated after the switching element has transitioned from a conduction state to a non-conduction state. ## Claims ### Claim 1 A circuit device comprising: a comparator that includes an input terminal and an output terminal, and outputs an output signal that is activated when a potential of the input terminal is lower than a determination level from the output terminal; a switch circuit that is electrically connected between an output node connected to a switching element that enters a conduction state or a non-conduction state according to a drive signal and the input terminal of the comparator, and is in a non-conduction state when the switching element is in a conduction state; and a control circuit that controls a level of the drive signal such that the switching element will not enter a conduction state again based on at least one of length of a period during which and the number of times the output signal of the comparator is activated after the switching element has transitioned from a conduction state to a non-conduction state. ### Claim 2 (depends on 1) The circuit device according to claim 1, wherein the switch circuit includes a high voltage transistor. ### Claim 3 (depends on 1) The circuit device according to claim 1, further comprising a clamp circuit that has one end connected to the input terminal of the comparator and another end connected to a power supply node on a low potential side, and clamps the potential of the input terminal of the comparator when the potential of the input terminal of the comparator becomes higher than the power supply potential on the low potential side by a predetermined value or more. ### Claim 4 (depends on 1) The circuit device according to claim 1, further comprising a protection circuit that has one end connected to the output node and another end connected to a power supply node on a low potential side, includes a transistor, and enters a conduction state when a potential of the output node becomes lower than a power supply potential on the low potential side by a forward voltage of a parasitic diode of the transistor or more. ### Claim 5 (depends on 4) The circuit device according to claim 4, wherein the transistor of the protection circuit includes a high voltage transistor. ### Claim 6 (depends on 4) The circuit device according to claim 4, wherein the comparator further includes a second input terminal to which the power supply potential on the low potential side is applied, an offset voltage that is smaller than the forward voltage of the parasitic diode of the transistor being set between the input terminal and the second input terminal, and compares the potential of the output node with a determination level that is lower than the power supply potential on the low potential side by the offset voltage. ### Claim 7 (depends on 1) The circuit device according to claim 1, the control circuit controls the level of the drive signal such that the switching element will not enter a conduction state again in a case where the number of times the output signal of the comparator is continuously activated during a second period after a first period has elapsed from when the switching element transitioned from a conduction state to a non-conduction state, reaches a predetermined number of times, which is two times or more. ### Claim 8 (depends on 1) The circuit device according to claim 1, further comprising the switching element that is connected between a power supply node on a high potential side and the output node, and, upon entering a conduction state according to the drive signal, supplies a power supply potential on the high potential side to the output node. ### Claim 9 (depends on 1) A switching regulator comprising: the circuit device according to claim 1; a Schottky barrier diode that has a cathode connected to the output node and an anode connected to a power supply node on a low potential side: an inductor that has one end connected to the output node, and is supplied with a drive current from the switching element; and a capacitor that is connected between another end of the inductor and the power supply node on the low potential side, and accumulates a charge supplied from the inductor. ### Claim 10 (depends on 9) An electronic apparatus comprising the switching regulator according to claim 9.