# US 12,763,741 B2 · Analog front-end circuit and touch-sensing circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,763,741 B2 - Document ID: US12763741B2 - Status: Granted - Kind: B2 - Application number: 18/137,663 - Filed: 2023-04-21 - Published: 2024-10-24 - Granted: 2026-10-13 - Earliest claimed: 2023-04-21 - Assignees: Kunshan Yunyinggu Electronic Technology Co., Ltd. - Applicants: Kunshan Yunyinggu Electronic Technology Co., Ltd. - Inventors: Kusuma Adi Ningrat; Hanif Fakhruddin - Web page: https://patentgrep.com/patent/US12763741B2 ## CPC - H03F 3/45475: {using IC blocks as the active amplifying circuit} - G06F 3/04182: {Filtering of noise external to the device and not generated by digitiser components} - H03F 1/26: Modifications of amplifiers to reduce influence of noise generated by amplifying elements - H03F 3/005: {using switched capacitors, e.g. dynamic amplifiers; using switched capacitors as resistors in differential amplifiers (H03F3/45 takes precedence)} - H03F 3/70: Charge amplifiers - H03F 2200/264: An operational amplifier based integrator or transistor based integrator being used in an amplifying circuit - H03F 2203/45136: One differential amplifier in IC-block form being shown - H03F 2203/45174: the application of the differential amplifier being in an integrator circuit - H03F 2203/45512: the FBC comprising one or more capacitors, not being switched capacitors, and being coupled between the LC and the IC - H03F 2203/45526: the FBC comprising a resistor-capacitor combination and being coupled between the LC and the IC - H03F 2203/45528: the FBC comprising one or more passive resistors and being coupled between the LC and the IC - H03F 2203/45551: the IC comprising one or more switched capacitors - H03F: AMPLIFIERS - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An analog front-end circuit includes a reference voltage source, a first capacitor, an amplifier, and a second capacitor. The first capacitor is coupled to the reference voltage source through a switch. The amplifier includes a first input end receiving a touch sensing signal from a touch sensor, a second input end receiving a reference signal from the first capacitor, and an output end outputting an output signal. The second capacitor is disposed between the first input end and the second input end. ## Claims ### Claim 1 An analog front-end circuit, comprising: a reference voltage source; a first capacitor coupled to the reference voltage source through a switch; an amplifier, comprising: a first input end receiving a touch sensing signal from a touch sensor; a second input end receiving a reference signal from the first capacitor; and an output end outputting an output signal; a second capacitor disposed between the first input end and the second input end; a third capacitor disposed between the first input end and the touch sensor; a fourth capacitor disposed between the first input end and a display panel; a fifth capacitor disposed between the first input end and the output end; a sixth capacitor comprising a first terminal coupled to the first input end and the fifth capacitor and a second terminal coupled to all of a first resistor, the second capacitor, the third capacitor, and the fourth capacitor; and the first resistor disposed between the output end and the third capacitor. ### Claim 2 (depends on 1) The analog front-end circuit of claim 1, wherein the first terminal is coupled to the first input end and the fifth capacitor, and the second terminal is coupled to the first resistor, the second capacitor, and the third capacitor. ### Claim 3 (depends on 2) The analog front-end circuit of claim 2, wherein a capacitance of the fifth capacitor is between 0.1 pF and 5 pF, and a capacitance of the sixth capacitor is between 0.1 pF and 5 pF. ### Claim 4 (depends on 2) The analog front-end circuit of claim 2, wherein a capacitance ratio of the fifth capacitor and the sixth capacitor is between 0.1 and 5. ### Claim 5 (depends on 1) The analog front-end circuit of claim 1, wherein a capacitance of the first capacitor is between 1 pF and 200 pF, and a capacitance of the second capacitor is between 50 fF and 5 pF. ### Claim 6 An analog front-end circuit, comprising: a reference voltage source; a first capacitor coupled to the reference voltage source through a switch; an amplifier, comprising: a first input end receiving a touch sensing signal from a touch sensor; a second input end receiving a reference signal from the first capacitor; and an output end outputting an output signal; a second capacitor disposed between the first input end and the second input end; a third capacitor disposed between the first input end and the touch sensor; a fourth capacitor disposed between the first input end and a display panel; a first resistor disposed between the output end and the third capacitor; a second resistor disposed between the first input end and the output end, wherein the first resistor and the second resistor are two different resistors; and a third resistor comprising a first terminal coupled to the first input end and the second resistor and a second terminal coupled to all of the first resistor, the second capacitor, the third capacitor, and the fourth capacitor, wherein the third resistor is located between the first resistor and the second resistor. ### Claim 7 (depends on 6) The analog front-end circuit of claim 6, wherein the first terminal is coupled to the first input end and the second resistor, and the second terminal is coupled to the first resistor, the second capacitor, and the third capacitor. ### Claim 8 (depends on 7) The analog front-end circuit of claim 7, wherein a resistance of the second resistor is between 200 ohms and 4000 ohms, and a resistance of the third resistor is between 200 ohms and 4000 ohms. ### Claim 9 (depends on 7) The analog front-end circuit of claim 7, wherein a resistance ratio of the second resistor and the third resistor is between 0.1 and 5. ### Claim 10 (depends on 1) The analog front-end circuit of claim 1, further comprising: an integrator circuit comprising: a first integrator input end coupled to the output end of the amplifier; a second integrator input end coupled to the reference voltage source; and an integrator output end. ### Claim 11 (depends on 10) The analog front-end circuit of claim 10, further comprising: a fourth resistor disposed between the first integrator input end and the output end of the amplifier; and a seventh capacitor disposed between the first integrator input end and the integrator output end. ### Claim 12 A touch sensing circuit, comprising: an analog front-end circuit, comprising: a reference voltage source; a first capacitor coupled to the reference voltage source through a switch; an amplifier, comprising: a first input end receiving a touch sensing signal from a touch sensor; a second input end receiving a reference signal from the first capacitor; and an output end outputting an output signal; a second capacitor disposed between the first input end and the second input end; a third capacitor disposed between the first input end and the touch sensor; a fourth capacitor disposed between the first input end and a display panel; a fifth capacitor disposed between the first input end and the output end; a sixth capacitor comprising a first terminal coupled to the first input end and the fifth capacitor and a second terminal coupled to all of a first resistor, the second capacitor, the third capacitor, and the fourth capacitor; and the first resistor disposed between the output end and the third capacitor; and an integrator circuit, comprising: a first integrator input end coupled to the output end of the amplifier; a second integrator input end coupled to the reference voltage source; and an integrator output end. ### Claim 13 (depends on 12) The touch sensing circuit of claim 12, wherein the first terminal is coupled to the first input end and the fourth capacitor, and the second terminal is coupled to the first resistor, the second capacitor, and the third capacitor. ### Claim 14 (depends on 12) The touch sensing circuit of claim 12, wherein the integrator circuit further comprises: a fourth resistor disposed between the first integrator input end and the output end of the amplifier; and a seventh capacitor disposed between the first integrator input end and the integrator output end. ### Claim 15 (depends on 1) The analog front-end circuit of claim 1, wherein the first resistor comprises a third terminal coupled to the output end and the fifth capacitor and a fourth terminal coupled to all of the second capacitor, the third capacitor, the fourth capacitor, and the sixth capacitor. ### Claim 16 (depends on 1) The analog front-end circuit of claim 1, wherein the second capacitor is between the second terminal and the second input end. ### Claim 17 (depends on 1) The analog front-end circuit of claim 1, wherein the third capacitor is between the second terminal and the touch sensor. ### Claim 18 (depends on 1) The analog front-end circuit of claim 1, wherein the fourth capacitor is between the second terminal and the display panel. ### Claim 19 (depends on 6) The analog front-end circuit of claim 6, wherein the first resistor comprises a third terminal coupled to the output end and the first resistor and a fourth terminal coupled to all of the second capacitor, the third capacitor, the fourth capacitor, and the third resistor. ### Claim 20 (depends on 6) The analog front-end circuit of claim 6, wherein the second capacitor is between the second terminal and the second input end.