A 32-Channel Front-End For Wireless Hid Using Inverse-Stf Pre-Filtering Technique

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 7.5 mu s per channel. Chopping and digital calibration are employed to achieve an offset voltage < 850 mu V 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 0.28mm(2) in 65nm CMOS and consumes 1.8mW from 1.2V supply.