摘要 |
A CMOS imager includes an array of CMOS active pixel sensors and multiple column readout circuits each of which is associated with a respective column of sensors in the array and can perform correlated double sampling of values from a sensor in the respective column. Each column readout circuit also includes a crowbar switch which selectively can be enabled to force the stored values to an operational amplifier-based charge sensing circuit via a pair of buses. The operational amplifier-based charge sensing circuit, which includes a pair of switched integrators each of which is coupled to one of the buses, provides a differential output based on the values stored by a selected one of the column readout circuits.
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