低压低温度系数带隙基准源的设计

Design of a Bandgap Reference with Low Voltage and Low Temperature Coefficient

基准源被广泛应用于数模转换器、锁相环等集成电路中,其输出电压的稳定性影响到整个系统的性能。采用高阶曲率补偿原理,设计了一种低压高精度带隙基准电压源。利用工作于亚阈值区的MOSFET栅源电压差所产生的非线性正温度系数电流来修正传统BJT带隙基准源的精度。使用CSMC 0.18μm CMOS工艺进行设计,流片后测试结果表明,在1.2 V电源电压下室温27℃时输出基准电压812 mV;低频时,电源抑制比达到-89 dB。在-35℃到115℃的宽温度范围内,温度系数为4.1×10^(-6)/℃。

The reference source is widely used in integrated circuits such as digital-to-analog converters(DAC)and phase-locked loops(PLL)whose output voltage stability affects the performance of the entire system.A low voltage and high precision bandgap reference voltage source is designed based on the principle of high order curvature compensation.The precision of the traditional Bipolar Junction Transistor(BJT)bandgap reference source is corrected by using the positive temperature coefficient current produced by the MOSFET working in the subthreshold region.The design is carried out through the CSMC 0.18μm CMOS process.The test results show that the output reference voltage is 812 mV at the temperature of 27℃and at power supply of 1.2 V.The Power Supply Rejection Ratio(PSRR)reaches-89 dB at low frequency.The temperature coefficient is 4.1×10^-6/℃at a wide temperature range from-35℃to 115℃.