一种低成本高精度电压张弛型振荡器  

A low-cost high precision voltage relaxation oscillator

作　　者：万美琳 吴逸飞 王洲 刘睿康 马莹晨 WAN Meilin;WU Yifei;WANG Zhou;LIU Ruikang;MA Yingchen(School of Microelectronics,Hubei University,Wuhan 430062,China;Suzhou Fullway Electronic Technology Co.,Ltd.,Suzhou 215000,China)

机构地区：[1]湖北大学微电子学院,湖北武汉430062 [2]苏州四方杰芯电子科技有限公司,江苏苏州215000

出　　处：《微电子学与计算机》2024年第12期69-76,共8页Microelectronics & Computer

基　　金：国家自然科学基金(62174050);中国工程科技发展战略研究湖北研究院咨询研究项目(HB2022B06)。

摘　　要：提出了一种具有高精度的低成本电压张弛振荡器。该振荡器使用双电容交替充放电结构,使得振荡器输出方波的高/低电平持续时间都只和基准电流对电容的充电时间有关,而和电容的放电时间无关,稳定了输出方波的占空比。电容的充电时间由基准电流和电容的容值决定,因此振荡器输出波形的频率具有较低的温漂。同时,该振荡器使用了三输入两输出的比较器来控制电容的充放电开关,省去了1/2分频电路,从而减少了数字逻辑引起的延迟和保持电容的电压过冲,提高了振荡器输出频率的稳定性。该振荡器采用SMIC 180 nm BCD工艺进行设计和制造,振荡频率为4 MHz,面积为0.0027 mm^(2)。测试结果表明,当温度从-40℃变化到125℃时,实测最大频率误差为0.9%、功耗为12.6μW。A low-cost voltage relaxation oscillator with high accuracy is proposed in this paper.It uses a dual capacitor alternating charging and discharging structure,so that the high/low level duration of the oscillator's output square wave is only related to the charging time of the reference current on one holding capacitor,and is independent of the discharge time of the capacitor,stabilizing the duty cycle of the output square wave.The charging time of the capacitor is determined by the reference current and the capacitance of the holding capacitor,so the frequency of the output wave has a low temperature drift.At the same time,the oscillator uses a three-input and two-output comparator to control the charging and discharging of the two holding capacitors,eliminating the need for a 1/2 divider circuit,thereby reducing the delay caused by digital logic and maintaining the voltage overshoot of the capacitor,and improving the stability of the oscillator's output frequency.The oscillator is designed and manufactured using SMIC 180 nm BCD process,with an oscillation frequency of 4 MHz and an area of 0.0027 mm^(2).The test results show that when the temperature changes from-40℃to 125℃,the maximum measured frequency error is 0.9%and the power consumption is 12.6μW.

关 键 词：电压张弛振荡器 三输入两输出比较器 保持电容 高精度 低成本 

分 类 号：TN432[电子电信—微电子学与固体电子学]