A programmable gain amplifier for Hall sensor

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), Dec.2025, Vol.48 No.12: 1615-1620

DOI: 10.3969/j.issn.1003-5060.2025.12.006

Authors

ZHANG Haozhe $ ^{1,2} $, CHEN Hongmei $ ^{1,2} $, FAN Kaixin $ ^{1,2} $, YIN Yongsheng $ ^{1,2} $

(1. Institute of VLSI Design, Hefei University of Technology, Hefei 230601, China; 2. IC Design Web-cooperation Research Center of Ministry of Education, Hefei University of Technology, Hefei 230601, China)

Abstract and Keywords

Abstract: This work presents a high linearity programmable gain amplifier (PGA) for Hall sensor. The PGA contains a two-stage structure: the first stage is an open-loop programmable amplifier based on symmetrical operational transconductance amplifier, which enables gain control and high response speed; the second stage is an instrumentation amplifier, which achieves extremely high common-mode rejection ratio (CMRR). To achieve a constant gain over a wide temperature range of $ -40\;^{\circ}C $ to $ 140\;^{\circ}C $, the resistance of Hall devices with a positive temperature coefficient is used as the loads of the first stage to compensate for the temperature variation of input signal from Hall plates, and a high-order temperature compensation is introduced to further reduce the temperature drift of sensitivity at high and low temperature ranges. To accommodate a wide input signal range, a single-pin programmable fuse trimming circuit is introduced to adjust the gain of the PGA. This work was designed and simulated in GF 180 nm BiCMOS process. The post-simulation results show that the gain range of PGA is from 46.4 dB to 65.5 dB, and the range of the sensitivity can be controlled from 1.5 mV/G to 15.8 mV/G. The linearity error is below 0.40% and the temperature drift of sensitivity is below 0.30% in the operation temperature range of $ -40\;^{\circ}C $ to $ 140\;^{\circ}C $.

Keywords: programmable gain amplifier (PGA); temperature compensation; high linearity; Hall sensor

作者信息

张昊哲 $ ^{1,2} $，陈红梅 $ ^{1,2} $，范凯欣 $ ^{1,2} $，尹勇生 $ ^{1,2} $

(1. 合肥工业大学微电子设计研究所, 安徽合肥 230601; 2. 合肥工业大学教育部 IC 设计网上合作研究中心, 安徽合肥 230601)

摘要和关键词

摘要: 文章设计一种用于霍尔传感器的高线性可编程增益放大器(programmable gain amplifier, PGA)。该PGA采用两级结构: 第1级为增益可变的基于对称型跨导放大器的开环放大器, 可实现增益控制与较高的响应速度; 第2级为仪表放大器, 可实现极高的共模抑制比(common-mode rejection ratio, CMRR)。为实现 $ -40\sim140 $℃范围内稳定的增益, 采用霍尔器件作为第1级的负载, 利用霍尔器件的正温度电阻特性对霍尔电压的负温度系数进行补偿, 并引入高阶温度补偿, 使得高温段和低温段的灵敏度温漂进一步降低; 为适应较宽的检测范围, 设计可通过单引脚编程的熔丝修调电路来调节PGA的增益, 并在GF 180 nm BiCMOS工艺下完成整体电路的设计与仿真。后仿结果表明: PGA的增益可调范围为46.4~65.5 dB, 灵敏度可调范围为1.5~15.8 mV/G; 在 $ -40\sim140 $℃的工作温度范围内, 灵敏度的线性误差小于0.40%, 温度漂移小于0.30%。

关键词: 可编程增益放大器（PGA）；温度补偿；高线性度；霍尔传感器

Funding

安徽省重点研究与开发计划资助项目（202104g01020008）

合肥工业大学学报(自然科学版)

Navigation