A 120.9-dB DR Digital-Input Capacitively Coupled Chopper Class-D Audio Amplifier

This article presents a digital-input class-D amplifier (CDA) achieving high dynamic range (DR) by employing a chopped capacitive feedback network and a capacitive digital-to-analog converter (DAC). Compared with conventional resistive-feedback CDAs driven by resistive or current-steering DACs, the proposed architecture eliminates the noise...

A Versatile ± 25-A Shunt-Based Current Sensor With ± 0.25% Gain Error From − 40 ∘ C to 85 ∘ C

This article presents a versatile shunt-based current sensor for battery management applications. It digitizes the current-induced voltage drop across an external shunt resistor with the help of a 2 nd -order delta-sigma ( ΔΣ ) ADC, whose summing node is implemented as a low-noise capacitively coupled amplifier. To compensate for the shunt’s...

A 121.4-dB DR Capacitively Coupled Chopper Class-D Audio Amplifier

This article presents a class-D amplifier (CDA) with high dynamic range (DR). To eliminate the typically dominant noise contribution of a resistive feedback network, the input and feedback signals are chopped and applied to a capacitive feedback network. However, this leads to high-voltage (HV) transients at the input of the loop filter,...

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...

A Capacitively Degenerated 100-dB Linear 20-150 MS/s Dynamic Amplifier

This paper presents a new dynamic residue amplifier topology for pipelined analog-to-digital converters. With an input signal of 100 mV_pp,diff and 4 × gain, it achieves-100-dB total harmonic distortion, the lowest ever reported for a dynamic amplifier. Compared to the state of the art, it exhibits 25 dB better linearity with twice...

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 15-Channel digital active electrode system for multi-parameter biopotential measurement

This paper presents a digital active electrode (DAE) system for multi-parameter biopotential signal acquisition in portable and wearable devices. It is built around an IC that performs analog signal processing and digitization with the help<br/>of on-chip instrumentation amplifiers, a 12 bit ADC and a digital interface. Via a standard bus, up to...