宽温度范围高精度带隙基准源设计

文章设计实现一种宽温度范围高精度高阶温度补偿带隙基准源。该结构利用正向偏置三极管负比于绝对温度(complementary to absolute temperature, CTAT)的基极-发射极电压 $ V_{BE} $与正比于绝对温度(proportional to absolute temperature, PTAT)的 $ \Delta V_{BE} $进行良好平衡，从而实现一阶温度补偿；同时利用分段温度补偿电路，实现低温段和高温段的曲率补偿，从而在宽温度范围内获得较低的温度漂移。为进一步提高输出精度，核心运放采用折叠式共源共栅结构以获得较高增益，并引入斩波技术，减小器件失配和噪声的影响；此外，为满足工艺一致性，设计了修调电路。该带隙基准源电路基于TSMC 0.18 $ \mu $m BCD工艺进行设计，在3.3~5.0 V电源电压下后仿真结果表明，温度范围为-40~125℃的条件下，所设计的带隙基准源在各工艺角下的温度系数均低于 $ 10^{-5} $℃ $ ^{-1} $，输出电压为2.5 V，静态功耗为45 $ \mu $A，电压精度误差低于0.2%。

In this paper, a high precision and high order temperature compensation bandgap reference with wide temperature range is designed and implemented. This structure achieves first-order temperature compensation by well balancing the base-emitter voltage $ V_{BE} $ of a forward-biased triode, which exhibits a complementary to absolute temperature (CTAT) characteristic, and the $ \Delta V_{BE} $ with a proportional to absolute temperature (PTAT) characteristic. In addition, the piecewise temperature compensation circuit is used to realize the curvature compensation of the low and high temperature sections, so as to achieve a low temperature drift in a wide temperature range. In order to further improve the output accuracy, the core operation amplifier adopts the folding common-source common-gate structure to obtain higher gain, and the chopper technology is added to reduce the influence of device mismatch and noise. Finally, in order to meet the process consistency, a trimming circuit is designed. The bandgap reference circuit is designed based on the TSMC 0.18 $ \mu $m BCD process. Post-layout simulation results show that with a supply voltage of 3.3-5.0 V and a temperature range of -40-125 $ ^{\circ} $C, the temperature coefficient of the designed bandgap reference at each process corner is lower than $ 10^{-5} $ $ ^{\circ} $C $ ^{-1} $, and the output voltage is 2.5 V. The static power consumption is 45 $ \mu $A, and the voltage accuracy error is less than 0.2%.