A Fully-integrated Analog Front-end for Carbon-based Short-wave Infrared Image Sensor

Abstract

Carbon Nanotube Field Effect Transistor (CNT-FET) have many advantages in electronics materials such as high mobility and ultra-thin body, which are promising for the fabrication of high performance, low power consumption and low cost shortwave infrared image sensors. In this paper, a column-level Analog Front-end (AFE) circuit is designed as a processing circuit for a carbon-based short-wave infrared image sensor, which includes Capacitor TransImpedance Amplifier (CTIA) integrator, Correlated Double Sampling (CDS), and 10bit/125KHz Successive AppRoximation Analog-to-Digital Converter (SAR ADC). The proposed AFE is designed using SMIC 0.18µm CMOS 1P6M process with area of 1.9mm ² and an power supply voltage of 1.8V. The post-simulation results show that the Signal-to-Noise Ratio (SNR) is 56.84dB and Signal-to-Noise and Distortion Ratio (SNDR) is 55.885dB. Meanwhile the Effective Number of Bits (ENOB) achieves 8.99bit. The range of detection current is 500p-100nA, and the power consumption is 7.01mW.