A low-power switched-capacitor capacitive transducer with high resolution

Abstract

A new capacitive transducer using a

pseudodifferential-input–single-ended output topology for lowpower

portable applications is presented. This is based on a

switched-capacitor chopper-stabilized pseudodifferential integrator

structure that is cascaded with a chopper-stabilized differential

difference amplifier, consisting of a single output and a bandpass

ac output. The measured results have shown that the transducer

integrated circuit, with a sampling rate of 64 kHz in a 0.6-μm

CMOS technology, dissipates 820 μA at a 3.3-V supply and

exhibits a low noise characteristic. For a 100-Hz bandwidth, the

input-referred minimum detectable capacitances are 57.24 and

33.82 aF with reference to the single output and the bandpass

output, respectively.