A New Opamp-less CMOS Bandgap Voltage Reference Circuit
Feng Shu, Wan Yonglu, Yuelong Zhang · 2012
Theory of bandgap reference voltage and conventional bandgap reference circuits were presented,and a novel bandgap reference circuit without op-amp was designed.In the circuit,MOS current mirrors and negative feedback clamping technique were used to avoid the use of operational amplifier,thus eliminating effects of offset and power supply rejection ratio(PSRR) of the operational amplifier on accuracy of bandgap voltage reference.Based on 0.18 μm standard CMOS process,the circuit was simulated using Spectre of Cadence.Simulation results showed that the bandgap voltage reference circuit had a temperature coefficient of 6.73×10-6/℃ in the temperature range from-40 ℃ to 125 ℃,and a PSRR of 54.8 dB,and it consumed 0.25 mW of power from 2.5 V supply.