Design of a low temperature floats bandgap reference without amplifier

Based on the basic theory of bandgap voltage reference,a bandgap reference with low temperature floats is proposed.Compared with the normal ones,there is no amplifier for the present bandgap reference.It has low temperature coefficient and high power supply rejection ratio(PSRR).To make sure that the circuit works in right condition,a startup circuit is added.Results from simulation show that the PSRR reaches 85 dB with low frequency,change of the output voltage is only 0.8 mV from-20 ℃ to 100 ℃,and the temperature coefficient is only 4.968 ×10-6.At normal temperature the output voltage is 1.296 V,and power voltage ranges from 3.9 V to 5.5 V.