An Energy-Efficient 3.7-nV/√ Hz Bridge Readout IC With a Stable Bridge Offset Compensation Scheme

This paper describes an energy-efficient bridge readout IC (ROIC), which consists of a capacitively coupled instrumentation amplifier (CCIA) that drives a continuous-time delta–sigma modulator (CTM). By exploiting the CCIA’s ability<br/>to block dc common-mode voltages, the bridge’s bias voltage may exceed the ROIC’s supply voltage, allowing...

Energy-Efficient Bridge-to-Digital Converters

This paper presents an overview of energy-efficient analog-to-digital converters (ADCs) specifically intended for the readout of Wheatstone bridge sensors. Apart from achieving good energy-efficiency, such bridge-to-digital converters (BDCs) must achieve low input-referred offset, drift and noise; high gain accuracy, stability and linearity;...

A 4.5 nV/√Hz Capacitively Coupled Continuous-Time Sigma-Delta Modulator with an Energy-Efficient Chopping Scheme

When chopping is applied to a continuous-time sigmadelta modulator (CTΣΔM), quantization noise fold-back often occurs, leading to increased in-band noise. This can be prevented by employing a return-to-zero (RZ) digital-to-analog converter (RZ DAC) in the modulator's feedback path and arranging the chopping transitions to coincide with its RZ...

A Power-Efficient Readout for Wheatstone-Bridge Sensors With COTS Components

This paper presents a direct digital converter for Wheatstone bridge sensors, which is realized with commercial off-the-shelf components. The power efficiency of the readout is enhanced by embedding the bridge sensor in a second-order continuous-time sigma-delta modulator (CTDeltaSigmaM). By directly digitizing the output signal of a Wheatstone...

A Gm-C Continuous-Time Sigma-Delta Modulator with Improved Linearity

Bridge sensors are widely used for accurate measurement of physical quantities such as temperature, pressure, strain or altitude. Such sensors require a low-noise, high-resolution and accurate readout system with high input impedance. In order to meet these requirements, conventional sensor readout systems use multiple stages which typically...