基于电阻网络修调的高精度基准源

High-Precision Reference Source Based on Resistor Network Trimming

针对高精度集成电路系统,工艺条件导致的误差需要通过修调弥补。基于0.18μm CMOS工艺设计了一种针对片上基准源的修调电路,通过调整数字输入信号,对电阻网络修调电路进行控制,通过重配置输出级电阻比例,从而达到对基准源电压的调整。基准源采用改进的Neuteboom带隙电路,在5 V电源电压的工艺条件下进行仿真测试,在-40~125℃温度范围内,实现了2.98×10^(-6)/℃的温度系数。通过电阻网络修调的基准电压变化范围为2.3840~2.5154 V,电压修调步长为2 mV。

For high-precision integrated circuit systems,errors caused by process conditions need to be compensated by trimming.Based on the 0.18μm CMOS process,a trimming circuit for the on-chip reference source is designed.Through adjusting digital input signal,the resistor network trimming circuit is controlled,and the output stage resistance ratio is reconfigured to achieve the adjustment of the reference source voltage.The reference source adopts the improved Neuteboom bandgap circuit,and the simulation test is carried out under the process condition of the supply voltage of 5 V.The temperature coefficient of 2.98×10^(-6)/℃is realized in the temperature range of-40-125℃.The variation range of the reference voltage trimmed by the resistor network is 2.3840-2.5154 V,and the voltage trimming step is 2 mV.