A 32-channel front-end for wireless HID using inverse-STF pre-filtering technique

摘要

A 32-channel front-end circuit for wireless Human Interface Devices (HID) is described. The front-end incorporates a Sigma-Delta ADC combined with an inverse-STF pre-filtering technique to achieve 10.8 ENOB at a conversion rate of 7.5µs per channel. Chopping and digital calibration are employed to achieve an offset voltage < 850µV and gain error < 0.17%. The HID front-end measures single-ended rail-to-rail inputs with 1.62V to 3.63V supply range, occupies 0.28mm² in 65nm CMOS and consumes 1.8mW from 1.2V supply.