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.

Biopotential multi-path current feedback instrumentation amplifier with automatic offset cancellation loop for resistive bridge microsensors

“…The LFP consists of five stages this is why its gain is very large compared to the gain of HFP, to obtain an offset-stabilized for the latter which has a residual offset at the input (Gm11). According to (6), we need to strengthen the LFP's gain in order to remove the HFP's offset, therefore Gm3 is designed as a gain-boosted single-stage folded-cascode OTA to reinforce the DC gain and bring down the HFP's offset to 1 µV [15]. The residual input offset can be expressed as (6) [20].…”

“…Micro-electro-mechanical systems (MEMS) technology is currently gaining significant attention due to the inherent advantages of miniaturization, high signal-to-noise ratio (SNR), and affordability, which has led to its ubiquitous application across a plethora of sensing devices [1]. Among these, resistive MEMS sensors stand out, offering a unique combination of structural simplicity, superior linearity, and robust durability, making them an optimal choice for the detection of various data, including but not limited to biological signals [2]- [6].…”

The 1.5 bit-per-stage 10-bit pipelined CMOS A/D converter for CMOS image sensor

“…In recent years, there has been increased interest in using images to interpret the world. CMOS image sensors (CIS) play a crucial role in this process by converting optical signals into electrical signals, serving as an interface between external objects and internal digital signal processor (DSP) systems [1]- [3]. A typical CIS device consists of a vertical shift register, a pipeline analog-to-digital converter array, a pixel array, a bias circuit, and a clock generator.…”