Design Of Bandgap Reference With High PSRR

When the temperature or power supply voltage VDD changes,the output voltage of the bandgap reference voltage is almost unchanged.This excellent performance allows the bandgap reference to play an important role in many circuit modules.With the development of analog integrated circuits,how to design a high performance bandgap reference are concerned by more and more analog engineers and scholars.It is in this context that this paper has studied the high PSRR of bandgap.This paper first investigates the significance of the study of bandgap benchmarking and the research hotspots in this field at home and abroad.Then,the basic principle of positive and negative temperature coefficient is analyzed,the loop gain of bandgap reference and the condition of loop stability are deduced.The effect of amplifier offset voltage on the accuracy of bandgap reference output voltage is discussed.The bandgap reference designed in this paper has three characteristics: low output voltage,high PSRR and low temperature drift coefficient.The bandgap reference consists of four different parts,namely the core of the bandgap reference circuit,amplifier,pre-conditioning circuit,start-up circuit.In this paper,the working principle of each part of the circuit are analyzed and the mathematical derivation,through the software simulation results and requirements indicators are compared.The difficulty of the circuit design lies in the design of pre-conditioning circuit and how to ensure that the circuit in all corners of the process still meet the requirements of indicators.In this paper,the current summation mode is used to achieve the purpose of low voltage output,Pre-conditioning circuit is used to increases the power supply rejection ratio and compensates for it.The simulation results show that: when VDD = 3.3V and the process angle is different,the simulation results meet thedesign requirements.To tt process angle as an example: the output is 0.8V;Power supply rejection ratio is 108.36 d B @ 100 Hz,72.33 d B @ 10 k Hz;Temperature drift coefficient is 2.65ppm/°C,the response time is 5.9?s.The simulation results meet the design requirements.