高精度分段曲率校正CMOS带隙基准的设计

本文提出了一种新颖的分段曲率校正技术,未增加额外掩模,在标准CMOS工艺条件下就可简单实现曲率校正,使带隙基准的温度系数减少约十倍.这种方法可应用到任何一种工艺获得非线性补偿.在SMIC 0.18μM CMOS 的工艺条件下,设计了一种高精度分段曲率校正全差分带隙基准.模拟结果表明输出差分参考电压为1.9997V,输出噪声电压为225nV/ Hz ,电源抑制比为98dB.并在CSMS 0.5μM混合信号工艺条件下,高精度分段曲率校正单端带隙基准嵌入到单片100MHz PWM控制BUCK DC-DC转换器中提供参考电压,测试结果表明参考电压为1.2501V,输出噪声电压为670Nv Hz ,电源抑制比为66.7dB,温度系数为2.7ppm/℃提高了6倍.本设计采用电流形式,因而通过改变参数,可使输出差分或单端参考电压小于1V,适合低压低功耗的便携式设备.

The Design of Precision Piecewise Curvature-Corrected CMOS Bandgap Reference

This paper presented a novel piecewise curvature-corrected technology,which can be accomplished in standard CMOS process technology without any extra masks for temperature compensation.Temperature coefficient is improved by ten Compared to the first order compensation.This novel curvature-correcting scheme can be used in almost any process technology yielding reliable temperature compensation.The additional circuitry required for this correction is compact and is easily implemented.In SMIC 0.18 μ M CMOS process,a precision piecewise curvature-corrected differential bandgap reference is designed.The simulation results show that differential reference is 1.9997V,total noise is 225nV,and PSRR is 98dB.Meantime,the precision piecewise curvature-corrected single-end bandgap reference implemented in CSMS 0.5 μ M process is embedded in a monolithic 100MHz PWM BUCK DC-DC converter as reference voltage.Experimental results show that reference voltage is 1.2501V,total noise is 670nV,PSRR is 66.7dB,and temperature coefficient is improved by six.Differential or single-end reference can be under 1V through changing parameters due to the current mode,which is adapted to low-voltage low-power portable devices.