DESIGN OF OPERATIONAL AMPLIFIERS FOR DELTA SIGMA ADCS

Author(s) : Aneeciya Mathew, Prameela B

Volume & Issue : VOLUME 2 / 2017 , ISSUE 1

Page(s) : 32-39


Abstract

The ADC is a key building block in the many application such as biomedical sensors, wireless application etc. They act as an interfacing media between analog domain and digital domain. In modern devices, it is desirable to integrate the entire analog frontend, back-end ADC and digital processor in a single chip, here low power is an important factor to be considered and ADCs are most power consuming part in such devices. Among different ADCs, the delta sigma converter has high-resolution, medium operating frequency and low-power consumption due to its simple architecture. The most power consuming part of delta sigma ADC is the modulator part or analog part due to the presences of operational amplifiers. This paper aims to design different operational amplifiers that are suitable for designing delta sigma ADC. Two stage op-amp with Miller compensation, folded cascode op-amp and telescopic op-amp are the three op-amp topologies, which are designed with input of 25 mV 1kHz , 1.8V supply voltage in 180nm technology.



Keywords

Delta Sigma ADC, Two stage op-amp, Folded cascade op-amp, Telescopic OP-amp, Oversampling ratio, Noise shaping.

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