Semiconductor imager and method with spatially separated proximate and distal reset gates to tune relative gain

Abstract

A semiconductor imager device is arranged for receiving a series of charge packets. It comprises a charge-to-voltage conversion circuit for receiving the charge packets on a reception capacitance and has an interconnected arrangement of a floating diffusion, a first reset gate, a reset drain and a source follower for readout. In particular, the device has a series arrangement of at least the first reset gate as a proximate reset gate and furthermore a distal reset gate, wherein in a high-gain configuration the proximate reset gate is cyclically controlled and the distal reset gate is continuously on, thus limiting the reception capacitance to a relatively low value. Alternatively, in a low-gain configuration the proximate reset gate is continuously on, thus extending the capacitance to a relatively high value and the distal reset gate replaces the proximate reset gate as being cyclically controlled for conversion of the series of charge packets.