Rapid start-up and fast stabilization PTAT current reference based on weak mismatch mechanism of operational amplifier

In order to solve the problems of long response speed and slow convergence speed of traditional PTAT current source during startup, a new PTAT current source with fast startup and stability is proposed. Based on the highly reliable bipolar structure, an operational amplifier structure with weak mismatch mechanism is introduced. By using local negative feedback and shared load capacitance, the chip area is optimized, and at the same time, the circuit startup speed and loop convergence stability speed are greatly accelerated. The circuit performance has been greatly improved in three aspects: power-on start-up, stable convergence and working mode. The results show that under the standard UMC 180 nm CMOS process, the circuit can achieve a wide temperature range of −40 C to 85℃, a wide swing voltage of 2.5-5 V, an average current of 104.26 μA, a startup speed of 4 μs and a high PSRR rejection ratio of 108 dB. It has a good application prospect in system chips with high requirements for startup and convergence speed.