基于BiCMOS工艺可修调的高精度低温度系数带隙基准源设计

设计了一种利用电阻比值校正一阶温度系数带隙基准电路的非线性温度特性来实现低温度系数的高精度低温度系数带隙基准源;同时设置了修调电路提高基准电压的输出精度.该带隙基准源采用0.8μm BiCMOS(Bipolar-CMOS)工艺进行流片,带隙基准电路所占面积大小为0.04 mm2.测试结果表明:在5 V电源电压下,在温度-40℃～125℃范围内,基准电压的温度系数为1.2×10-5/℃,基准电流的温度系数为3.77×10-4/℃;电源电压在4.0 V～7.0 V之间变化时,基准电压的变化量为0.4 mV,电源调整率为0.13 mV/V;基准电流的变化量为变化量约为0.02μA,电源调整率为6.7 nA/V.

Design of High Precision Low Temperature Coefficient Bandgap Reference with Trimming Based on BiCMOS Process

A high precision low temperature coefficient bandgap reference is designed. The bandgap reference source corrects the non-linear temperature characteristic of the bandgap reference circuit of the first-order temperature coefficient by using the ratio of the resistance,so that the accuracy and the temperature coefficient of the reference voltage are greatly improved. The trimming circuit is also used to improve the output accuracy of the reference voltage. 0.8 μm BiCMOS( Bipolar-CMOS) process was used to fabricate the wafers. The bandgap reference circuit occupied 0.04 mm2. The results show that the temperature coefficient of the reference voltage is 1.2×10-5/℃ and the temperature coefficient of the reference current is 3.77×10-4/℃ in the temperature range of -40 ℃～125 ℃under the 5 V power supply voltage. When the power supply voltage changes between 4.0 V～7.0 V,the variation of the reference voltage is 0. 4 mV and power supply regulation rate is 0. 13 mV/V, the variation of the reference current is about 0.02 μA and power supply regulation rate is 6.7 nA/V.