高精度CMOS温度传感器关键技术研究.pdfVIP

摘 要 摘 要 本文对实现高精度CMOS温度传感器的斩波技术进行了系统研究，利用斩波 技术实现了一种适用于SOC的高精度带隙基准源设计，有效地减小了带隙基准源 中运放的失调所引起的误差，大大提高了基准源的精度。当负载电流镜或差分输 入对存在2 ％的失配时，该基准源的输出波动峰峰值为0.394mV ，与传统结构的带 隙基准源相比，相对精度提高了87倍。在室温下斩波频率为100KHz 时，基准源 提供0.768V 的输出电压。当电源电压在1V 到1.5V 变化时，该基准源输出电压波 动小于0.03mV ；当温度在0 ℃到80 ℃变化时，该基准源的温度系数小于12-ppm/ ℃。基准源的最大功耗小于4.5µA，采用0.25µm 2P5M CMOS 工艺实现的版图面 2 积为0.3 ×0.4mm 。为适应模拟电路对低电源电压的要求，基于TSMC 0.25µm CMOS工艺的PMOS衬底驱动技术，采用电流反馈技术设计了低压 CMOS PTAT 电 压基准源电路。采用Hspice进行仿真，电源电压为0.8V ，室温下的电源电流为 4.5µA ，温度范围为0～100℃，输出电压温度系数为0.926mV/K ；当电源电压从 0.7~1.0V变化时，室温下的输出电压约为302mV 。不仅具有良好的温度线性度， 还具有高电源抑制比和低功耗特性。整个PTAT基准源的版图有效面积为0.2 × 2 0.06mm 。 关键词：温度传感器 带隙基准 斩波 PTAT CMOS ABSTRACT Abstract A discussion of the chopper technology applied to realizing high precision CMOS temperature sensors is detailed. Then a low voltage bandgap reference (BGR), for SOC application with high accuracy, is designed using the chopper technology to compensate the offset error caused by the MOSFET mismatch. The BGR fluctuating output peak-to- peak value is 0.394mV when 2% mismatches have occurred. Compared with the traditional BGR, the accuracy of this circuit is increased by 87 times. The design features a reference voltage of 0.768V at room temperature and chopper frequency 100KHz. With supply voltage range from 1V to 1.5V, the fluctuation of the output voltage is approximately 0.03mV and the temperature coefficient is about 12-ppm/ ℃ within a temperature range from 0℃ to 80 ℃. The maximum supply current is 4.5µA and the circuit layout occupies a die area of 0.3 ×0.4mm2 with a standard 0.25µm 2P5M CMOS process. In addition, ba