An APS-H-Size 250Mpixel CMOS Image Sensor Using Column Single-Slope ADCs with Dual-Gain Amplifiers

Abstract

We have developed an APS-H-sized 250Mpixel CMOS image sensor implemented with Single Slope ADC with dual gain amplifier (SSDG-ADC) to shorten the AD conversion period and widen the dynamic range without a rise in power consumption. In the SSDG-ADC, the gain of the column amplifier is set to high gain when a pixel signal level is lower than a certain threshold level. The gain is set down to low gain when the pixel level is higher. As a result, the 250Mpixel sensor with SSDG-ADC performs in about 75% shorter AD conversion period and 6dB wider dynamic range than a Single Slope ADC (SS-ADC).