A CMOS Self-Bias CTAT Current Generator with Improved Supply Sensitivity

Abstract

The role of complimentary to absolute temperature (CTAT) circuit in current mode bandgap has been described. Loop-gain problems with the existing self-bias MOS-based CTAT generator were discussed. A simple modification to the existing circuit was proposed to enhance the loop-gain by [Formula: see text]20[Formula: see text]dB without adding additional circuitry leading to zero additional power consumption. Power Supply Rejection and sensitivity to [Formula: see text] will be improved due to the higher loop-gain. A prototype has been developed to demonstrate the proposal robustness across PVT corners. Simulation results show 20.5[Formula: see text]dB PSRR improvement and 7.5% improvement in sensitivity to [Formula: see text]. The proposed solution consumes 180[Formula: see text]nW power from 1[Formula: see text]V power supply voltage and occupies 3300[Formula: see text][Formula: see text]m2 silicon area.