低温度与工艺增益误差的可变增益放大器设计-AET-电子技术应用

低温度与工艺增益误差的可变增益放大器设计

电子技术应用

顾美庆1，黄伟1，2，曹华1

1.南京中科微电子有限公司；2.中国科学院微电子研究所

摘要： 采用0.18 μm工艺，设计了一种适用于高精度测温系统中的可变增益放大器，相比于传统的前置放大器，采用开环结构避免了反馈网络漏电流对前端采样电路的影响。通过与电源电压无关的电流源给跨导放大器电路提供电流，产生一个不包含工艺参数的跨导，最后通过运算放大器获得一个与电源电压、温度和工艺参数无关的增益。通过改变全差分跨导放大器的负载，来实现10倍和40倍可变增益。仿真结果表明，放大倍数为10倍时，增益随温度最大误差为0.19 dB，增益随电源电压最大误差为0.15 dB，增益随工艺偏差为0.12 dB。放大倍数为40倍时，增益随温度最大误差为0.16 dB，增益随电源电压最大误差为0.23 dB，随工艺偏差为0.13 dB。

关键词： 可变增益放大器共源共栅电流源跨导放大器共栅共源放大器低温度增益误差

中图分类号：TN722 文献标志码：A DOI: 10.16157/j.issn.0258-7998.256550
中文引用格式： 顾美庆，黄伟，曹华. 低温度与工艺增益误差的可变增益放大器设计[J]. 电子技术应用，2025，51(10)：47-51.
英文引用格式： Gu Meiqing，Huang Wei，Cao Hua. A variable gain amplifier designed with low gain variation at temperature and process[J]. Application of Electronic Technique，2025，51(10)：47-51.

A variable gain amplifier designed with low gain variation at temperature and process

Gu Meiqing1，Huang Wei1，2，Cao Hua1

1.Nanjing Zhongke Microelectronics Co.， Ltd.；2.Institute of Microelectronics of Chinese Academy of Sciences

Abstract： A pre-variable gain amplifier for high precision temperature measuring system is designed in 0.18 μm process, compared with the traditional preamplifier, and the influence of the feedback network leakage on the front-end sampling circuit is avoided by using the opening loop structure. Through the current source of the power voltage, the current is provided for the cross-guide amplifier circuit, which produces a transconductance that does not contain the process parameters, and then the gain unrelated to voltage supply, temperature, and process parameters is obtained by the operation amplifier. By changing the load of the whole difference cross-amplifier amplifier, 10 and 40 times variable gain are implemented. The simulation results show that when the amplification gain is 10 times, the maximum gain variation with temperature is 0.19 dB, the maximum gain variation with voltage supply is 0.15 dB, the maximum gain variation with process is 0.12 dB. When the amplification gain is 40 times, the maximum gain variation with temperature is 0.16 dB, the maximum gain variation with voltage supply is 0.23 dB, the maximum gain variation with process is 0.13 dB.

Key words : variable gain amplifier；co-source common grid current source；transconductance amplifier；co-source common grid amplifier；low temperature gain error；low process gain error

引言

随着物联网的发展与普及，越来越多的应用场景需要通过各类传感器精密感知物理世界的参数，如温度、湿度、压力等，将传感器获得的弱电信号进行处理，并转换为数字信号，所以需要用到模/数转换器（ADC）处理并转换这些现实世界的信号[1]。在高精度测温系统中，由于温度信号变化缓慢且信号幅值非常小，因此需要高分辨率的模数转换器（ADC）进行处理，但这将会极大提高ADC的设计难度和复杂程度[2]。因此，通常在ADC前端引入前置可变增益放大器（VGA）对信号进行预处理，如图1高精度测温系统框图中所示。

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