School of Microelectronics, Shanghai University, Shanghai 201800, China.
The Shanghai Industrial μTechnology Research Institute, Shanghai 201899, China.
Sensors (Basel). 2023 May 29;23(11):5169. doi: 10.3390/s23115169.
This paper proposes a temperature sensor based on temperature-frequency conversion using 180 nm CMOS technology. The temperature sensor consists of a proportional-to-absolute temperature (PTAT) current generating circuit, a relaxation oscillator with oscillation frequency proportional to temperature (OSC-PTAT), a relaxation oscillator with oscillation frequency independent of temperature (OSC-CON), and a divider circuit cascaded with D flip-flops. Using BJT as the temperature sensing module, the sensor has the advantages of high accuracy and high resolution. An oscillator that uses PTAT current to charge and discharge capacitors to achieve oscillation, and utilizes voltage average feedback (VAF) to enhance the frequency stability of the oscillator is tested. Through the dual temperature sensing process with the same structure, the influence of variables such as power supply voltage, device, and process deviation can be reduced to a certain extent. The temperature sensor in this paper was implemented and tested with a temperature measurement range of 0-100 °C, an inaccuracy of +0.65 °C/-0.49 °C after two-point calibration, a resolution of 0.003 °C, a resolution Figure of Merit (FOM) of 6.7 pJ/K, an area of 0.059 mm, and a power consumption of 32.9 μW.
本文提出了一种基于 180nmCMOS 技术的温度-频率转换温度传感器。该温度传感器由一个与绝对温度成正比的电流产生电路（PTAT）、一个与温度成正比的弛豫振荡器（OSC-PTAT）、一个与温度无关的弛豫振荡器（OSC-CON）和一个由 D 触发器级联的除法电路组成。该传感器使用 BJT 作为温度感测模块，具有高精度和高分辨率的优点。该传感器采用 PTAT 电流对电容器进行充电和放电以实现振荡，并利用电压平均反馈（VAF）增强振荡器的频率稳定性。通过相同结构的双温度感测过程，可以在一定程度上降低电源电压、器件和工艺偏差等变量的影响。本文实现并测试了一种温度传感器，其测量范围为 0-100°C，经过两点校准后精度为+0.65°C/-0.49°C，分辨率为 0.003°C，分辨率品质因数（FOM）为 6.7pJ/K，面积为 0.059mm²，功耗为 32.9μW。
