A power-efficient current generator with common mode signal autozero feedback for bioimpedance measurement applications

This paper describes the design of fully differential sine pulse-width-modulation (SPWM) wave current generator for bioimpedance measurement applications. The current generator has been designed in a 0.18-µm CMOS technology. Its analog front-end operates from ±1.65 V and has a current consumption of + + ( ×. ) where is the output current and is the operating frequency. It can provide outputs from to of SPWM current up to 98 kHz with a maximum voltage compliance of ±1.25 V. Using linear current feedback, the current generator has a designed transconductance of /. Feedback also enables cancellation of common mode signals and a high output impedance