A high accuracy bandgap reference with chopped modulator to compensate MOSFET mismatch

摘要

A design of a low voltage bandgap reference (BGR), for SOC application with high accuracy, is described and the chip layout is presented. To compensate the error caused by the current-mirror mismatch, the chopper modulator is used in the BGR to decrease the offset of the opamp. The design features a reference voltage of 0.256V/spl sim/0.768V with supply voltage range from 1 V to 1.5 V and temperature range from -20 /spl deg/C to 60 /spl deg/C. The maximum supply current is 4 /spl mu/A and the area of layout is 0.3 /spl times/ 0.4 mm/sup 2/ with a standard 0.25 /spl mu/m 2P5M n-well CMOS process.