In-Pixel CTIA & Readout Circuitry for an Active CMOS Image Sensor

Abstract

This work aims to design and simulate an in-pixel Capacitive Transimpedance Amplifier (CTIA) and peripheral circuitry that ensures pixel reading. Each pixel circuit is composed of four transistors using 90nm CMOS technology with a supply voltage of 1.8 V and is part of an array of pixels that make up a CMOS image sensor with peripheral circuitry. Pixel output is sent to a delta difference sampling (DDS) circuit to filter reset voltages. The Gain Margin achieved for the in-pixel CTIA is 44dB and 91dB for the Phase Margin. We also present measured pixel parameters and give a comparison with prior work. The timing and readout circuitry is also described.