# US 2024/0204544 A1 · Circuit device and electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0204544 A1 - Document ID: US20240204544A1 - Status: Published application - Kind: A1 - Application number: 18/543,297 - Filed: 2023-12-18 - Published: 2024-06-20 - Earliest claimed: 2022-12-20 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Masaya Ninomiya; Kinya Matsuda - Web page: https://patentgrep.com/patent/US20240204544A1 ## CPC - H02J 7/61: against overcharge - H02J 7/663: {using battery or load disconnect circuits (H02J9/002 takes precedence)} - H02J 7/68: using circuits for correcting or protecting against reverse-polarity - H02J 7/80: including monitoring or indicating arrangements - H02J 7/933: {the cycle being controlled or terminated in response to electric parameters} - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY ## Abstract A circuit device includes a charging circuit and a discharging circuit. The charging circuit is configured to supply a charging current to a battery based on a power supply voltage from a power supply node. The discharging circuit is provided on an output side of the charging circuit, and is configured to discharge a leakage current leaking from the power supply node to the output side of the charging circuit when supply of the charging current is off. ## Claims ### Claim 1 A circuit device comprising: a charging circuit configured to supply a charging current to a battery based on a power supply voltage from a power supply node; and a discharging circuit provided on an output side of the charging circuit, wherein the discharging circuit is configured to discharge a leakage current leaking from the power supply node to the output side of the charging circuit when supply of the charging current is off. ### Claim 2 (depends on 1) The circuit device according to claim 1, wherein the discharging circuit discharges the leakage current after a full charge of the battery is detected. ### Claim 3 (depends on 1) The circuit device according to claim 1, further comprising: a reverse protection circuit provided between the charging circuit and the battery and configured to prevent reverse flow from the battery to the charging circuit, wherein the discharging circuit is coupled to an input-side node of the reverse protection circuit. ### Claim 4 (depends on 3) The circuit device according to claim 3, wherein the reverse protection circuit includes a transistor provided between the input-side node and a charging node, and the transistor includes a parasitic diode whose forward direction is a direction from the input-side node to the charging node. ### Claim 5 (depends on 1) The circuit device according to claim 1, wherein the discharging circuit sets a voltage on the output side of the charging circuit to be equal to or lower than a battery voltage by discharging the leakage current. ### Claim 6 (depends on 1) The circuit device according to claim 1, wherein the discharging circuit includes a resistance circuit and a switch that are provided in series between the output side of the charging circuit and a ground node. ### Claim 7 (depends on 6) The circuit device according to claim 6, wherein a resistance value of the resistance circuit is set to a resistance value such that, when the charging circuit is off, the battery is fully charged, an operating temperature is a maximum operating temperature, and a power supply voltage is applied to the power supply node, a voltage at output of the charging circuit is equal to or lower than a voltage of the battery at a time of full charge. ### Claim 8 (depends on 6) The circuit device according to claim 6, wherein the resistance circuit is a variable resistance circuit. ### Claim 9 (depends on 8) The circuit device according to claim 8, further comprising: a monitor circuit configured to monitor the voltage on the output side of the charging circuit and the voltage of the battery; and a control circuit configured to set a resistance value of the variable resistance circuit based on a monitor result of the monitor circuit. ### Claim 10 (depends on 1) The circuit device according to claim 1, wherein the discharging circuit includes a current source circuit provided between output of the charging circuit and a ground node. ### Claim 11 (depends on 10) The circuit device according to claim 10, wherein a current value of a current flowing through the current source circuit is set to a current value such that, when the charging circuit is off, the battery is fully charged, an operating temperature is a maximum operating temperature, and a power supply voltage is applied to the power supply node, a voltage at the output of the charging circuit is equal to or lower than a voltage of the battery at a time of full charge. ### Claim 12 (depends on 10) The circuit device according to claim 10, wherein the current source circuit is a variable current source circuit. ### Claim 13 (depends on 1) The circuit device according to claim 1, wherein the discharging circuit includes a switch, and the switch and a variable resistance circuit provided in the charging circuit are provided in series between a node on the output side of the charging circuit and a ground node. ### Claim 14 (depends on 1) The circuit device according to claim 1, wherein the charging circuit includes a transistor provided between the power supply node and output of the charging circuit, and an amplifier circuit configured to control a gate voltage of the transistor, and when supply of the charging current is off, the transistor is off, and the discharging circuit discharges the leakage current leaking from the power supply node to the output of the charging circuit via the transistor being off. ### Claim 15 (depends on 1) The circuit device according to claim 1, wherein the charging circuit includes a first charging circuit configured to generate a first charging current, and a second charging circuit configured to generate a second charging current smaller than the first charging current. ### Claim 16 (depends on 15) The circuit device according to claim 15, wherein the discharging circuit is configured to discharge the leakage current when the first charging circuit and the second charging circuit are in a disabled state. ### Claim 17 (depends on 1) An electronic device comprising: the circuit device according to claim 1; and the battery.