一种低工艺敏感度,高PSRR带隙基准源

实现了一种高精度带隙基准源,该基准源在预调节电路中应用了电源行波减法技术,显著改善了输出电压的电源抑制比。提出了采用电流负反馈技术稳定预调节电路电流的方法,降低了带隙基准的温度特性和电源抑制比对阈值电压的敏感度。考虑晶体管阈值电压发生±20%变化的情况下,仿真得到的基准源的温度系数和电源抑制比变化分别只有0.11ppm和7dB。测试结果表明,该基准源在-20～100℃的范围内的有效温度系数为25.7ppm/℃,低频电源抑制比为-68dB。其功耗为0.5mW,采用中芯国际0.35μm5-V混合信号CMOS工艺实现,有效芯片面积为300μm×200μm。

A Low Process Sensitivity,High PSRR Band-gap Reference

A high-precision bandgap reference is presented in this paper. The bandgap reference uses a pre-regulator with supply ripple subtraction technique to improve its power supply rejection ratio (PSRR). The current negative feedback technique is introduced in the pre-regulator to stabilize its output current,which improves the sensitivity of temperature coefficient and PSRR to threshold variation. Considering the ±20% variation of transistor threshold,the simulated variation of temperature coefficient (TC) and PSRR are 0.11 ppm and 7 dB respectively. The measurement result shows TC of 25.7 ppm/℃ from -20℃ to 100℃ and the PSRR of -68 dB in low frequency are achieved. The power consumption is 0.5 mW. It is fabricated by using SMIC 0.35 μm 5-V mixed-signal CMOS process with the effective area of 300 μm×200 μm.