Omnivision Technologies, Inc.

Zhihao Xu

Guangbin Zhang

Liang Zuo

Liping Deng

Bi Yuan

Yuxin Wang

A ramp generator for use in readout circuitry includes an integrator coupled to receive a ramp generator input reference signal to generate a reference ramp signal coupled to be received by an analog to digital converter. A power supply compensation circuit that is coupled to generate the ramp generator input reference signal includes a delay circuit including a variable resistor and a filter capacitor coupled to receive a power supply signal. The variable resistor is tuned to match a delay ripple from the power supply to a bitline output. A capacitive voltage divider is coupled to the delay circuit to generate the ramp generator input reference signal. The capacitive voltage divider includes a first variable capacitor coupled to a second variable capacitor that are tuned to provide a capacitance ratio that matches a coupling ratio from the power supply to the bitline output.

Image sensor power supply rejection ratio improvement through ramp generator in continuous time readout circuitry

A circuit for providing signal amplification with reduced fixed pattern noise. In an embodiment, the circuit includes an amplifier and a plurality of legs coupled in parallel with one another between a first node for an input of the amplifier and a second node for an output of the amplifier. Control logic selects a first combination of the plurality of legs for a first configuration of the circuit to provide a first loop gain with the amplifier. In another embodiment, the control logic further selects a second combination of the plurality of legs for a second configuration of the circuit to provide a second loop gain with the amplifier, wherein the first loop gain is substantially equal to the second loop gain.

Selective gain control circuit

An example image sensor includes a plurality of pixels arranged in an array of columns and rows, a row driver, and a control logic circuit. The row driver is coupled to pixels in a row of the array to provide a variable driving voltage to drive transistors included in the pixels of the row. The control logic circuit is coupled to provide one or more control logic signals to the row driver. The row driver adjusts a magnitude of the driving voltage in response to the one or more control logic signals.

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Sunnyvale, CA, United States of America

Zhihao Xu