A novel bandgap reference for minimizing current-mirror mismatch

A novel bandgap reference for minimizing current-mirror mismatch is presented. In the proposed circuit, the small-signal current variations in the two current paths are self-compensated while in the conventional bandgap core they are multiplied. As a result, error caused by current-mirror mismatch has been much reduced in the proposed circuit. Moreover, the voltage variations caused by temperature and supply voltage changes which make the small-signal current in the bandgap core vary can also be minimized. Based on the 0.6 um BiCMOS process technology, the error caused by current-mirror mismatch has been reduced by about 50 times in the proposed bandgap core and the complete circuit achieves a low temperature coefficient of 2.3 ppm/°C and a high power supply rejection ratio (PSRR) of 72 db without any PSRR boosting technique. On typical working conditions, the proposed circuit consumes only a supply current of 3.6 uA.