A 0.8-V 816-nW delta–sigma modulator for low-power biomedical applications

Abstract

This letter discusses the implementation of a low-voltage, low-power delta-sigma modulator as a sensing stage for biomedical applications. A distributed feedforward structure and bulk-driven operational transconductance amplifier are used in order to achieve efficient operation at a supply voltage of 0.8 V. Instead of conventional low-voltage amplifier architectures, our design uses folded-cascode amplifiers, although they are not used in most low-voltage circuits. A wide input swing is achieved by using the bulk-driven approach, and the drawback of the limited voltage swing of the cascoded output stage is overcome by the distributed feed-forward modulator. The designed modulator has a dynamic range of 49 dB at a 0.8-V supply voltage and consumes only 816 nW of power for the 250-Hz bandwidth. The core chip size of the modulator is 1000 lm 9 500 lm by using the 0.18-lm standard CMOS process.

Prototipo sensor de imagen CMOS con arquitectura de modulación a nivel columna

“…Para el prototipo CIS una SQNR entre 30 y 50 dB es aceptable, requiriendo el diseño de un solo integrador. Hoy día, aplicaciones de espectrometría clínica y bioluminiscencia se implementan con ΣΔM de 1er-orden (Perelman et al, 2001;Roh et al, 2009;Singh et al, 2011;Jung, 2013).…”

A 0.4-V 6.6-<i>µ</i>W 75-dB SNDR delta-sigma modulator employing gate-body-driven amplifier with local CMFB loop and robust clock generator for implantable biomedical devices

“…Low power, medium speed, and high resolution Delta-Sigma modulators (DSMs) are indispensable for effective detection of the cardiac signals with frequency band ranging from 0.01 to 300Hz or neural signals with frequency band ranging from sub-1Hz to 100Hz. Recently many DSMs have been reported for implantable biomedical devices in [13,14,15,16,17,18,19,20,21]. Most of the ULV DSMs are implemented by discrete-time (DT) topology.…”

A 300-mV ΔΣ Modulator Using a Gain-Enhanced, Inverter-Based Amplifier for Medical Implant Devices

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