# US 11,310,455 B2 · Tail current boost circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,310,455 B2 - Document ID: US11310455B2 - Status: Granted - Kind: B2 - Application number: 16/746,373 - Filed: 2020-01-17 - Published: 2021-07-22 - Granted: 2022-04-19 - Earliest claimed: 2020-01-17 - Assignees: Sony Semiconductor Solutions Corporation - Applicants: Sony Semiconductor Solutions Corporation - Inventors: Golan Zeituni; Noam Eshel - Web page: https://patentgrep.com/patent/US11310455B2 ## CPC - H03F 3/08: controlled by light - H03F 3/45183: {Long tailed pairs (H03F3/4521, H03F3/45237 take precedence)} - H03F 1/223: {with MOSFET's} - H03F 1/483: {with field-effect transistors} - H03F 3/45475: {using IC blocks as the active amplifying circuit} - H03F 3/505: {with field-effect devices} - H03F 3/70: Charge amplifiers - H04N 25/78: Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters - H03F 2200/36: the amplifier comprising means for increasing the bandwidth - H03F 2203/45244: the differential amplifier contains one or more explicit bias circuits, e.g. to bias the tail current sources, to bias the load transistors - H03F 2203/45514: the FBC comprising one or more switched capacitors, and being coupled between the LC and the IC - H03F 2203/45544: the IC comprising one or more capacitors, e.g. coupling capacitors - H03F: AMPLIFIERS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image sensor and electronic apparatus comprise a pixel circuit configured to generate an analog signal; a vertical signal line configured to convey the analog signal from the pixel circuit; an analog amplifier circuit configured to receive the analog signal via the vertical signal line and generate an amplified signal; and a tail current boost circuit configured to modify an instantaneous gain bandwidth product of the analog amplifier circuit by temporarily modifying a tail current of the analog amplifier circuit. ## Claims ### Claim 1 An image sensor comprising: a pixel circuit configured to generate an analog signal; a vertical signal line configured to convey the analog signal from the pixel circuit; an analog amplifier circuit configured to receive the analog signal via the vertical signal line and generate an amplified signal; and a tail current boost circuit configured to modify an instantaneous gain bandwidth product of the analog amplifier circuit by temporarily modifying a tail current of the analog amplifier circuit. ### Claim 2 (depends on 1) The image sensor according to claim 1, wherein the tail current boost circuit comprises a transistor, a feedback capacitor, and a current source. ### Claim 3 (depends on 2) The image sensor according to claim 2, wherein a gate of the transistor is coupled to an output node of the analog amplifier circuit. ### Claim 4 (depends on 2) The image sensor according to claim 2, wherein a source of the transistor is coupled to a first electrode of the feedback capacitor and to the current source. ### Claim 5 (depends on 4) The image sensor according to claim 4, wherein a second electrode of the feedback capacitor is selectively electrically connected to an output node of the analog amplifier circuit. ### Claim 6 (depends on 2) The image sensor according to claim 2, wherein the feedback capacitor is a variable capacitor. ### Claim 7 (depends on 1) The image sensor according to claim 1, wherein the analog amplifier circuit includes a first current source configured to provide a base tail current, and the tail current boost circuit includes a second current source configured to selectively provide a temporary discharge current to the analog amplifier circuit such that an effective tail current of the analog amplifier circuit is the base tail current minus the temporary discharge current, or a temporary charge current to the analog amplifier circuit such that the effective tail current of the analog amplifier circuit is the base tail current plus the temporary charge current. ### Claim 8 (depends on 1) The image sensor according to claim 1, wherein the analog amplifier circuit includes a feedback amplifier. ### Claim 9 (depends on 1) The image sensor according to claim 1, further comprising a processing circuit configured to receive the amplified signal from the analog amplifier circuit. ### Claim 10 (depends on 9) The image sensor according to claim 9, wherein the processing circuit includes a sample-and-hold circuit and an analog-to-digital converter. ### Claim 11 An electronic apparatus comprising: an image sensor including: a pixel circuit configured to generate an analog signal, a vertical signal line configured to convey the analog signal from the pixel circuit, an analog amplifier circuit configured to receive the analog signal via the vertical signal line and generate an amplified signal, and a tail current boost circuit configured to modify an instantaneous gain bandwidth product of the analog amplifier circuit by temporarily modifying a tail current of the analog amplifier circuit. ### Claim 12 (depends on 11) The electronic apparatus according to claim 11, wherein the tail current boost circuit comprises a transistor, a feedback capacitor, and a current source. ### Claim 13 (depends on 12) The electronic apparatus according to claim 12, wherein a gate of the transistor is coupled to an output node of the analog amplifier circuit. ### Claim 14 (depends on 12) The electronic apparatus according to claim 12, wherein a source of the transistor is coupled to a first electrode of the feedback capacitor and to the current source. ### Claim 15 (depends on 14) The electronic apparatus according to claim 14, wherein a second electrode of the feedback capacitor is selectively electrically connected to an output node of the analog amplifier circuit. ### Claim 16 (depends on 12) The electronic apparatus according to claim 12, wherein the feedback capacitor is a variable capacitor. ### Claim 17 (depends on 1) The electronic apparatus according to claim 1, wherein the analog amplifier circuit includes a first current source configured to provide a base tail current, and the tail current boost circuit includes a second current source configured to selectively provide a temporary discharge current to the analog amplifier circuit such that an effective tail current of the analog amplifier circuit is the base tail current minus the temporary discharge current, or a temporary charge current to the analog amplifier circuit such that the effective tail current of the analog amplifier circuit is the base tail current plus the temporary charge current. ### Claim 18 (depends on 11) The electronic apparatus according to claim 11, wherein the analog amplifier circuit includes a feedback amplifier. ### Claim 19 (depends on 11) The electronic apparatus according to claim 11, the image sensor further comprising a processing circuit configured to receive the amplified signal from the analog amplifier circuit. ### Claim 20 (depends on 19) The electronic apparatus according to claim 19, wherein the processing circuit includes a sample-and-hold circuit and an analog-to-digital converter.