A process variation insensitive bandgap reference with self-calibration technique

A process variation insensitive bandgap reference with self-calibration is presented. The initial accuracy of the bandgap reference is improved with self-calibration. The offset voltage caused by components mismatch due to process variation is averaged with a 6-bit resistor trimming array and the code for trimming is generated by the circuit itself. The 3σ inaccuracy of the bandgap reference decreases from ±12.6% to ±1.0% with the self-calibration. The circuit consumes 43.5μW and occupies 0.025mm² in a standard 65nm 1P6M CMOS technology.