Research And Design Of Bandgap Reference Circuit Based On Bipolar Technology

A bandgap reference voltage source is the basic module of analog integrated circuit, which is widely used in all kinds of circuits. In this paper, firstly, the development history and current situation of bandgap reference is summarized, the advantages and characteristics of the bandgap reference based on bipolar process are discussed, the significance of this research is pointed out. Then it introduces the related theory and process model of the design. This paper introduces the basic principle of bandgap reference, introduces several classical structure and main performance indexes of bandgap reference, and analyses the error factors of bandgap reference.Based on the application requirements of the charge management system, two kinds of bandgap references are determined respectively. And the differences between the structure and performance of the two circuits are compared and analyzed. The typical bandgap reference temperature coefficient compensation methods are introduced in detail, and the applicability of these methods in the application environment and circuit structure is analyzed. The characteristics of different temperature coefficients of two different types of resistors are used, and generates the PTAT2 and PTAT3 voltages which can compensate the high order terms of the base emitter voltage of the transistor. The temperature coefficient of the designed bandgap reference is optimized.Using CSMC 2um36v bipolar process, the whole circuit is simulated by spectre cadence simulation tool. The error of the resistance compensation method in the process of temperature coefficient compensation is analyzed, and the solution is put forward. Using cadence virtuoso tool to draw the layout. The model matching problem in the process of bipolar process layout verification is analyzed, and the solving methods are proposed. Using Hspice for post simulation. The temperature coefficient of the bandgap which applied to the switching power supply chip is 3.18ppm/℃, The PSRR is greater than 98.8dB in the range of 0-71.3Hz, the linear adjustment rate is 0.01mV/V, the starting time is 15.2us; The temperature coefficient of the bandgap reference which applied to the charge control chip is only 2.17ppm/℃, The PSRR is greater than 105dB in the range of 0-10.56Hz, the linear adjustment rate is 0.0044mV/V, the starting time is 215us. The simulation results show that it meets the needs of application.