PROJECT TITLE :

A Low-Power Incremental Delta–SigmaADC for CMOS Image Sensors - 2016

ABSTRACT:

This brief presents a second-order incremental delta-sigma analog-to-digital converter (ADC) for CMOS image sensors (CISs). The ADC that employs a cascade of integrators with a feedforward architecture uses only one operational transconductance amplifier (OTA) by sharing the OTA between the primary and second stages of the modulator. Further power and space savings are achieved by using a self-biasing amplifier and also the proposed level-shifting technology, that allows active signal summation at the quantizer input node without using an additional OTA. Fabricated within the zero.eighteen-µm CIS method, the ten-bit ADC occupies a die space of 0.002 mm2 and consumes 29.5 µW from a one.8-V supply. The measured differential nonlinearity and integral nonlinearity are but +zero.twenty two/-0.a pair of and +0.71/-0.eighty nine LSB, respectively. Operating at 20 MS/s, the ADC provides signal-to-noise-distortion ratios of fifty seven.7 and sixty two.three dB for signal bandwidths of 156.twenty five and 78.a hundred twenty five kHz, respectively.