Untrimmed BGR of 1.1% 3σ Based on Dynamic-Biased Op Amp With Reduced Voff

摘要

This brief presents an untrimmed sub-1V CMOS bandgap reference (BGR) where a dynamic-biased error amplifier (EA) is invented to accomplish small input-referred offset voltage (V-off) and improve PSRR of BGR. In the dynamic-biased EA, an intended negative-feedback loop does dominantly work on the reduction of V-off and supply noise influx. Simulation results confirm that V-off of the proposed EA represents 2.3% distribution whereas each V-off of the separate biased EA and the conventional EA shows 4.8% and 15% distributions, respectively. And the PSRR of the proposed EA-based BGR is increased by 23 dB comparing with the separate biased EA-based BGR around 2.5 MHz, and by 34 dB comparing with the conventional biased EA-based BGR around 1 MHz. By adopting the proposed feedback-biased EA, the 40-nm CMOS BGR circuit has been implemented to achieve superior 3 sigma inaccuracy of 1.1% and temperature variation of 13 ppm/degrees C without trimming.