University of Michigan

Kyojin Choo

David Theodore Blaauw

Dennis Sylvester

Li Xu

Sechang Oh

Seok Hyeon Jeong

Rohit Rothe

An amplifier is presented with a sample and average common mode feedback resistor. The amplifier circuit includes a feedback capacitor and a feedback resistor in parallel with the feedback capacitor, where the feedback capacitor and the feedback resistor form part of the negative feedback path for the amplifier. Of note, the feedback resistor is comprised of a low pass filter in series with a switched capacitor resistor, such that the low pass filter is electrically coupled to the output of the amplifier circuit and the switched capacitor resistor is electrically coupled to the inverting input of the amplifier circuit. The amplifier circuit further includes a control circuit interfaced with switches of the switched capacitor resistor. The high pass corner of the switched capacitor resistor is preferably lower than corner of the low pass filter.

Amplifier with sample and average common mode feedback resistor

An analog-to-digital converter (ADC) circuit is present, which is particularly suitable for use in an image sensor. The ADC circuit includes a comparator and a digital-to-analog converter (DAC) circuit. The DAC circuit includes two or more charge paths electrically coupled to the output node. Each charge path is formed by one or more charge-injection cells electrically coupled via a gain capacitor to the output node, and a charge conversion capacitor electrically coupled in parallel with the one or more charge-injection cells. Each charge-injection cell is configured to transfer a fixed amount of charge from a charge source to an associated charge path and includes at least one switch configured to isolate the charge source from the output node.

Analog-to-digital conversion circuit and image sensor including the same

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Ann Arbor, MI, United States of America

Kyojin Choo