Design of Compensation Bandgap Reference
Zou Wei-hua · Yuhang jice jishu · 2005
A High accurate CMOS bandgap reference(BGR) is described in this paper. With current mirror technique, the output of opamp makes drive it as being a self-bias ,and the voltages of bipolar's emitter-base junction are the input of the Opamp, so it achieves a proportional to absolute temperature current I_PTAT. Also, the voltages of resistor and bipolar's base-emitter junction are the input of the Opamp, so it achieves a complementary to absolute temperature current I_CTAT. Through current's subtraction, two different compensation currents I_NL can be achieved in the whole temperature range, so there are different compensation voltages and it can accomplish the piece-wise compensation to the BGR. Therefore, we get the bandgap reference voltage with very small temperature coefficient. When the supply voltage is 1.8 V, the simulation result is that the temperature coefficient is 1.88 ppm/V between -40℃ and 130℃, and its power supply rejection ratio is about -86 dB in low frequency, and the power dissipation is 237.5μW ,with TSMC standard 0.18 μm 1.8/3.3 1P6M CMOS process.