A CMOS Bandgap Voltage Reference Source Based on Chopper Technology
Zhang Lei · 2010
A bandgap voltage reference source with high PSRR and low temperature coefficient was designed.In this circuit,temperature drift caused by offset of the amplifier was reduced by using chopper modulation and dynamic element matching.Based on CSMC's 0.5 μm CMOS process,the bandgap voltage reference was simulated with Hspice.Results from simulation showed that,for a chopping frequency of 1.5 MHz,the circuit had an output reference voltage of about 1.235 V.At room temperature(25 ℃),its supply voltage ranged from 3.3 V to 5.5 V.At 3.3 V supply voltage and in the temperature range from-40 ℃ to 85 ℃,the bandgap voltage reference source had a temperature coefficient of 5.19×10-6 and a PSRR greater than 70 dB at 1 kHz.