High-Speed 16-Bit SAR-ADC Design at 500 MS/s with Variable Body Biasing for Sub-Threshold Leakage Reduction

Abstract

In this study, a high-performance 16-bit, 500 MS/s successive approximation register analog-to-digital con-verter (SAR-ADC) with variable body biasing (VBB) for re-ducing sub-threshold leakage is designed and optimized. The suggested ADC architecture makes use of a voltage threshold complementary metal-oxide-semiconductor (VTCMOS) cir-cuit with Widlar current mirror technology to efficiently con-sume 39.2 μW at an operating voltage of 1.0 V. Notably, the optimized ADC achieves outstanding performance measures, such as a signal-to-noise and distortion ratio (SNDR) of 97 dB and a total harmonic distortion (THD) of -97.97 dB, which are crucial markers of the ADC's accuracy and fidelity. An over-view of the growing need for high-resolution ADCs in contem-porary high-speed data conversion systems opens the study. The main goal of this effort is to improve overall ADC per-formance and tackle the problem of sub-threshold leakage. The Widlar current mirror technology and the VTCMOS cir-cuit are integrated for enhanced linearity, decreased current mismatch errors, and minimized leakage current. This inte-gration is highlighted in the full explanation of the ADC de-sign. The advent of the VBB approach as a successful method of leakage reduction is a significant contribution to this re-search. The theoretical foundations and workings of the VBB technique are discussed, and thorough simulations and tests are used to assess how the VBB technique affects leakage cur-rent and circuit performance. The SAR-ADC design and simulations were carried out using Cadence Virtuoso soft-ware.