# US 12,002,822 B2 · Metal-oxide-semiconductor capacitor based passive amplifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,002,822 B2 - Document ID: US12002822B2 - Status: Granted - Kind: B2 - Application number: 17/134,809 - Filed: 2020-12-28 - Published: 2022-06-30 - Granted: 2024-06-04 - Earliest claimed: 2020-12-28 - Assignees: Semiconductor Components Industries, LLC - Applicants: Semiconductor Components Industries, LLC - Inventors: Manuel H. Innocent - Web page: https://patentgrep.com/patent/US12002822B2 ## CPC - H10F 39/803: {Pixels having integrated switching, control, storage or amplification elements} - H03M 1/1245: {Details of sampling arrangements or methods} - H03M 1/466: {using switched capacitors} - H04N 25/59: by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the floating node capacitance - H04N 25/77: Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components - H04N 25/78: Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A passive amplifier is provided that includes an input sampling switch, a sampling capacitance, and metal-oxide-semiconductor capacitor devices. An input signal may be sampled onto the sampling capacitance by turning on the input sampling switch while the metal-oxide-semiconductor capacitors are activated. After the sampling phase, the metal-oxide-semiconductor capacitors are deactivated to provide a voltage gain. The voltage gain can be conditionally applied depending on the signal level of the sampled input. ## Claims ### Claim 1 An image sensor, comprising: an image sensor pixel; a column line configured to receive a signal from the image sensor pixel; and a passive amplifier circuit comprising: an input port configured to receive the signal from the column line; an output port; a sampling switch having a first terminal coupled to the input port and having a second terminal coupled to the output port; and a metal-oxide-semiconductor capacitor having a gate terminal configured to receive a control signal and having source-drain terminals coupled to the output port. ### Claim 2 (depends on 1) The image sensor of claim 1, wherein the passive amplifier circuit further comprises: a capacitor having a first terminal coupled to the output port and having a second terminal configured to receive a reference voltage; and an additional metal-oxide semiconductor capacitor having a gate terminal configured to receive an inverted version of the control signal and having source-drain terminals coupled to the output port. ### Claim 3 (depends on 2) The image sensor of claim 2, wherein the metal-oxide-semiconductor capacitor comprises an n-type metal-oxide-semiconductor capacitor and wherein the additional metal-oxide-semiconductor capacitor comprises a p-type metal-oxide-semiconductor capacitor. ### Claim 4 (depends on 2) The image sensor of claim 2, wherein the metal-oxide-semiconductor capacitor and the additional metal-oxide-semiconductor capacitor are activated during a charge sampling phase and are deactivated during an amplification phase. ### Claim 5 (depends on 4) The image sensor of claim 4, wherein the reference voltage has a given voltage level during the charge sampling phase and has the given voltage level during the amplification phase. ### Claim 6 (depends on 4) The image sensor of claim 4, wherein the reference voltage has a first voltage level during the charge sampling phase and has a second voltage level, different than the first voltage level, during the amplification phase. ### Claim 7 (depends on 2) The image sensor of claim 2, wherein the passive amplifier circuit further comprising: a comparator having an input coupled to the first terminal of the capacitor and an output on which the control signal is generated. ### Claim 8 (depends on 7) The image sensor of claim 7, wherein the comparator is configured to deassert the control signal when the signal at the input port is within a predetermined voltage range. ### Claim 9 An amplifier, comprising: an input port; an output port; a sampling switch having a first terminal coupled to the input port and having a second terminal coupled to the output port; and a metal-oxide-semiconductor capacitor having source-drain terminals coupled to the output port and having a gate terminal configured to receive a control signal. ### Claim 10 (depends on 9) The amplifier of claim 9, further comprising: an additional metal-oxide-semiconductor capacitor having source-drain terminals coupled to the output port and having a gate terminal configured to receive an inverted version of the control signal. ### Claim 11 (depends on 10) The amplifier of claim 10, further comprising: a capacitor having a first terminal coupled to the output port and having a second terminal configured to receive a reference voltage. ### Claim 12 (depends on 11) The amplifier of claim 11, wherein: the control signal is driven high during a charge sampling operation; the control signal is driven low during an amplification operation; the reference voltage has a first voltage level during the charge sampling operation; and the reference voltage has the first voltage level or a second voltage level, different than the first voltage level, during the amplification operation. ### Claim 13 (depends on 11) The amplifier of claim 11, wherein: the control signal is driven high during a sampling operation; and the control signal is driven low during an amplification operation. ### Claim 14 (depends on 11) The amplifier of claim 11, wherein: the reference voltage has a first voltage level during the sampling operation; and the reference voltage has the first voltage level or a second voltage level, different than the first voltage level, during the amplification operation. ### Claim 15 (depends on 10) The amplifier of claim 10, wherein the metal-oxide-semiconductor capacitor comprises an n-type metal-oxide-semiconductor capacitor and wherein the additional metal-oxide-semiconductor capacitor comprises a p-type metal-oxide-semiconductor capacitor. ### Claim 16 (depends on 10) The amplifier of claim 10, wherein the metal-oxide-semiconductor capacitor and the additional metal-oxide-semiconductor capacitor are activated during a first phase and are deactivated during a second phase different than the first phase. ### Claim 17 (depends on 16) The amplifier of claim 16, wherein the first phase comprises a sampling phase and wherein the second phase comprises an amplification phase. ### Claim 18 (depends on 9) The amplifier of claim 9, further comprising: a comparator having an input coupled to the second terminal of the sampling switch and an output at which the control signal is produced. ### Claim 19 (depends on 18) The amplifier of claim 18, wherein the comparator is configured to deassert the control signal when a signal at the input port is within a predetermined voltage range. ### Claim 20 (depends on 18) The amplifier of claim 18, further comprising: an inverter having an input coupled to the output of the comparator and to the gate terminal of the metal-oxide-semiconductor capacitor.