A design of a three-stage bandgap reference voltage source

In order to reduce the temperature coefficient (TC) of bandgap voltage reference source, a voltage reference source based on SMIC 0.18μm CMOS process was designed. The TC is an important performance index of voltage reference source, and segmented compensation technology is an effective method to reduce the TC of voltage reference source. In this paper, the reference source is divided into three temperature zones, and the three-stage reference voltage is obtained by superimposing different compensation voltages in each temperature zone, and the TC of the reference voltage is effectively reduced. The designed bandgap reference voltage source works in the range of -40 to 125℃, the TC is 0.94 ppm/℃, and the smallest TC tested is about 15.69 ppm/℃. Simulation and experimental results show that the circuit can effectively improve the temperature performance of bandgap reference voltage source.