使用动态元件匹配技术的带隙基准源的设计

Design of a bandgap reference source with dynamic elements matching

为了改善器件失配引起的误差对带隙基准精度及稳定性的影响,设计了一款基于BICMOS 0.15μm工艺的带隙基准电压源。电路使用传统的带隙基准结构,为了提高增益,采用两级放大器;为了解决器件失配造成的不稳定性,采用了动态元件匹配技术。经过spectre仿真表明:此基准源能够很好地改善器件失配带来的误差,从而保证基准源的精度以及稳定性,5.0V供电、温度在233K(-40℃)~378K(105℃)变化时,相比于没有使用动态元件匹配的电路,该电路最少能够减小68%的误差;典型温度298K(25℃)、电压在4.5~5.5V变化时,相比于没有使用动态元件匹配的电路,该电路最少能够减小70%的误差。仿真结果显示,电路具有高稳定性。

To improve the accuracy and stability problem of bandgap reference source caused by elements mismatching error, a bandgap reference source based on BICMOS 0.15μm BCD process was designed. The circuit is based on traditional bandgap reference structure with a two-stage amplifier for increasing gain. The technology of dynamic elements matching (DEM) was used to solve the elements mismatching problem. Spectre simulation results show that this reference circuit can solve the elements mismatching problem perfectly, ensuring the accuracy and stability of reference source. Under the power voltage of 5.0 V, with the temperature ranging from 233 K (-40℃) to 378 K(105℃), this circuit can reduce 68% of the error at least by comparison with the circuit without DEM;Under the temperature of 298 K (25℃), with the power voltage ranging from 4.5 V to 5.5 V, this circuit can reduce 70% of the error at least by comparison with the circuit without DEM. It can be concluded that this circuit is of high stability.