A novel RC time constant tuning technique utilizing programmable current sources for continuous-time delta-sigma modulators

Abstract

A novel RC time constant tuning technique for continuous-time delta-sigma modulators is proposed to alleviate the systematic time constant shift originating from process variations. The proposed tuning technique uses programmable current sources instead of capacitor banks in order to reduce the implemented die area. MATLAB/Simulink simulation results demonstrate that this technique can achieve the desired SQNR even with ±30% RC time constant shifts.