# US 12,224,675 B2 · Voltage detection circuit, switching converter and integrated circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,675 B2 - Document ID: US12224675B2 - Status: Granted - Kind: B2 - Application number: 17/747,282 - Filed: 2022-05-18 - Published: 2022-12-22 - Granted: 2025-02-11 - Earliest claimed: 2021-06-18 - Assignees: Silergy Semiconductor Technology (Hangzhou) LTD - Applicants: Silergy Semiconductor Technology (Hangzhou) LTD - Inventors: Jiabin Chen; Hongxing Wang - Web page: https://patentgrep.com/patent/US12224675B2 ## CPC - H02M 3/33592: {having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer} - G01R 19/10: Measuring sum, difference or ratio - G01R 19/16547: {voltage or current in AC supplies (switching for protection H02H; circuits for emergency power supply H02J9/00)} - H02M 1/0003: {Details of control, feedback or regulation circuits} - H02M 3/156: with automatic control of output voltage or current, e.g. switching regulators - 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) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A voltage detection circuit for a switching converter having a switch and a magnetic element connected in series, where a first terminal of the switch and a first terminal of the magnetic element are connected to a common node, the voltage detection circuit including: an average circuit configured to receive a first voltage across the switch, and to generate a second voltage representing an average value of the first voltage; and where the second voltage represents a voltage between a second terminal of the switch and a second terminal of the magnetic element in a steady state of the switching converter. ## Claims ### Claim 1 A voltage detection circuit for a switching converter having a switch and a magnetic element connected in series, wherein a first terminal of the switch and a first terminal of the magnetic element are connected to a common node, the voltage detection circuit comprising: a) a low-pass filter configured to receive a first voltage across the switch, and to generate a second voltage representing an average value of the first voltage; b) wherein the second voltage represents a voltage between a second terminal of the switch and a second terminal of the magnetic element in a steady state of the switching converter; and c) wherein the switching converter is configured as a Boost converter, the switch is connected between the common node and a negative input terminal of the switching converter, the magnetic element is connected to a positive input terminal of the switching converter and the common node, and the second voltage represents an input voltage of the switching converter. ### Claim 2 (depends on 1) The voltage detection circuit of claim 1, wherein the second voltage represents one of: an input voltage of the switching converter, an output voltage of the switching converter, and a difference between the input voltage and the output voltage. ### Claim 3 (depends on 1) The voltage detection circuit of claim 1, wherein a reference ground of the low-pass filter and a reference ground of a control circuit of the switching converter are both connected to the second terminal of the switch. ### Claim 4 (depends on 1) The voltage detection circuit of claim 1, wherein the magnetic element comprises an inductor or a winding of a transformer. ### Claim 5 (depends on 1) The voltage detection circuit of claim 1, further comprising a control circuit configured to control a switching state of the switch according to the second voltage output by the voltage detection circuit. ### Claim 6 (depends on 1) An integrated circuit, comprising the voltage detection circuit of claim 1, and the switch of the switching converter. ### Claim 7 A voltage detection circuit for a switching converter having a switch and a magnetic element connected in series, wherein a first terminal of the switch and a first terminal of the magnetic element are connected to a common node, the voltage detection circuit comprising: a) a low-pass filter configured to receive a first voltage across the switch, and to generate a second voltage representing an average value of the first voltage; b) wherein the second voltage represents a voltage between a second terminal of the switch and a second terminal of the magnetic element in a steady state of the switching converter; and c) wherein the switching converter is configured as a Buck converter, the switch is connected between the common node and a positive input terminal of the switching converter, the magnetic element is connected to a positive output terminal of the switching converter and the common node, and the second voltage represents a difference between an input voltage and an output voltage of the switching converter. ### Claim 8 (depends on 7) The voltage detection circuit of claim 7, wherein the second voltage represents one of: an input voltage of the switching converter, an output voltage of the switching converter, and a difference between the input voltage and the output voltage. ### Claim 9 (depends on 7) The voltage detection circuit of claim 7, wherein a reference ground of the average circuit and a reference ground of a control circuit of the switching converter are both connected to the second terminal of the switch. ### Claim 10 (depends on 7) The voltage detection circuit of claim 7, wherein the magnetic element comprises an inductor or a winding of a transformer. ### Claim 11 A voltage detection circuit for a switching converter having a switch and a magnetic element connected in series, wherein a first terminal of the switch and a first terminal of the magnetic element are connected to a common node, the voltage detection circuit comprising: a) a low-pass filter configured to receive a first voltage across the switch, and to generate a second voltage representing an average value of the first voltage; b) wherein the second voltage represents a voltage between a second terminal of the switch and a second terminal of the magnetic element in a steady state of the switching converter; and c) wherein the switching converter is configured as a Buck converter, the switch is connected between the common node and a negative input terminal of the switching converter, the magnetic element is connected to a negative output terminal of the switching converter and the common node, and the second voltage represents a difference between an input voltage and an output voltage of the switching converter. ### Claim 12 A voltage detection circuit for a switching converter having a switch and a magnetic element connected in series, wherein a first terminal of the switch and a first terminal of the magnetic element are connected to a common node, the voltage detection circuit comprising: a) a low-pass filter configured to receive a first voltage across the switch, and to generate a second voltage representing an average value of the first voltage; b) wherein the second voltage represents a voltage between a second terminal of the switch and a second terminal of the magnetic element in a steady state of the switching converter; and c) wherein the switching converter is configured as a Buck-Boost converter, the switch is connected between the common node and a positive input terminal of the switching converter, the magnetic element is connected to a negative output terminal of the switching converter and the common node, and the second voltage represents an input voltage of the switching converter. ### Claim 13 A voltage detection circuit for a switching converter having a switch and a magnetic element connected in series, wherein a first terminal of the switch and a first terminal of the magnetic element are connected to a common node, the voltage detection circuit comprising: a) a low-pass filter configured to receive a first voltage across the switch, and to generate a second voltage representing an average value of the first voltage; b) wherein the second voltage represents a voltage between a second terminal of the switch and a second terminal of the magnetic element in a steady state of the switching converter; c) wherein the switching converter is configured as a Flyback converter; d) wherein when the low-pass filter is used to detect a voltage across the switch at a primary side, the second voltage is used to represent an input voltage of the switching converter, and e) wherein when the low-pass filter is used to detect a voltage across the switch at a secondary side, the second voltage is used to represent an output voltage of the switching converter. ### Claim 14 (depends on 13) The voltage detection circuit of claim 13, wherein the magnetic element is a primary winding connected between a positive input terminal of the switching converter and the common node, and the switch at the primary side is connected between the common node and the negative input terminal of the switching converter. ### Claim 15 (depends on 13) The voltage detection circuit of claim 13, wherein the magnetic element is a secondary winding connected between the common node and a negative terminal of the switching converter, and the switch at secondary side is connected between the common node and the positive output terminal of the switching converter. ### Claim 16 (depends on 13) The voltage detection circuit of claim 13, wherein the magnetic element is a secondary winding connected between the common node and a positive output terminal of the switching converter, and the switch at the secondary side is connected between the common node and the negative output terminal of the switching converter. ### Claim 17 (depends on 13) The voltage detection circuit of claim 13, wherein the second voltage represents one of: an input voltage of the switching converter, an output voltage of the switching converter, and a difference between the input voltage and the output voltage. ### Claim 18 (depends on 13) The voltage detection circuit of claim 13, wherein a reference ground of the average circuit and a reference ground of a control circuit of the switching converter are both connected to the second terminal of the switch. ### Claim 19 (depends on 13) The voltage detection circuit of claim 13, wherein the magnetic element comprises an inductor or a winding of a transformer.