Digitally-controlled automatic gain control circuits for CMOS CCD camera interface

Automatic gain control circuit (AGC) design techniques for CMOS CCD camera interface systems are described. The required gain of the proposed AGC is controlled directly by digital bits. The amplifying function of the AGC is divided into three stages for high-speed operation. A capacitor-segment combination technique considerably improves the effective bandwidth of the AGC. While the three-stage prototype shows 32 dB AGC dynamic range in 1/8 dB steps, the proposed two-stage AGC reduces the power and chip area further