کنفرانس مهندسی برق ایران

صفحه اصلی / سی امین کنفرانس بین المللی مهندسی برق

A Third-Order Noise-Shaping SAR ADC With Optimized NTF Zeros for IOT Applications

نویسندگان :

Mansoure Yousefirad¹ Mohammad Yavari²

1- دانشگاه امیرکبیر (پلی تکنیک) 2- دانشگاه امیرکبیر (پلی تکنیک)

کلمات کلیدی :

SAR ADC, Noise-Shaping, NTF zeros optimization, EF-filter, FF, Passive integrator.

چکیده :

This article presents a fully dynamic, simple and area efficient third order noise shaping successive approximation register analog to digital converter (NS-SAR ADC) that is suitable for internet of thing (IOT) applications. This work utilizes a passive integrator in feed forward (FF) path of a second order error-feedback (EF) NS-SAR ADC to enhance its in-band quantization noise suppression effect. This integrator is very simple and area efficient because built just with a switch and a capacitor. Integrator attenuation arising from charge-sharing is compensated with embedded comparator relative gain of 4. The noise transfer function (NTF) zeros are optimized. In this work sampling frequency, bandwidth and over-sampling ratio (OSR) are 3.2 MS/S, 200 kHz and 8 respectively. The proposed structure is investigated systematically by MATLAB software. Using proposed technique, a 3rd order NS-SAR ADC is obtained and the signal to noise and distortion ratio (SNDR) of the ADC is enhanced from 94.7dB to 104.3dB.