Chapter 11 - A low-power reconfigurable ADC for bioimpedance monitoring system

Abstract

This chapter introduces a reconfigurable pipeline analog-to-digital converter (ADC) deliberated for implantable surveillance devices for bioimpedance applications. To improve the efficiency of the bioimpedance method, an automatic adaptation circuit is introduced. This adaptive unit is responsible for setting the resolution and sampling rate on the basis of amplitude and frequency of the signal. Using a new, low-power automatic adaptation circuit, it can automatically determine its setup. The converter has two modes of operations. In high-resolution mode, the converter has a 12-bit resolution, and low is 8-bit resolution. The ADC bandwidth of low-speed mode is 100kHz and high-speed mode is 1GHz. For signal-to-noise distortion ratio, effective number of bits, and low power consumption, the converter utilizes 71.06dB, 11.45 in 12-bit and 72.3dB, 7.41 in 8-bit mode.