摘要
设计了一种频率可调,低温漂、结构简单的张弛振荡器。该振荡器利用基准电压和负反馈的钳位作用,通过改变外部电阻的阻值来线性改变振荡周期。利用电容两端电压不能突变的原理,使得每次充放电电容电压跳变后都远离反相器的阈值,这样便忽略阈值对振荡器的影响,并且省去了常规结构中的迟滞比较器,简化了电路结构,减小了振荡器的复位延时。基于0.18μm BCD(Bipolar-CMOS-DMOS)工艺模型,采用Cadence和Hspice进行仿真。在典型应用下,振荡器的频率范围为500 k Hz^2 MHz,温度在–20^+120℃变化时,振荡器的频率随温度变化的偏移量在±2.76%以内。
An output frequency adjustable, temperature drift low,structure simple relaxation oscillator was designed. Using clamp effect of the reference voltage and negative feedback, the period of oscillation of the oscillator was linearly changed by altering the resistance value of the external resistor. Based on the principle that the voltage on both ends of the capacitor can not mutate, the hopping capacitor voltage after each charge and discharge were far away from the threshold point of the inverter and eliminated the hysteresis comparator in conventional structure which could simplify the circuit structure and reduce the oscillator reset delay. Based on 0.18 μm BCD process mode, in typical applications, simulation by Cadence and Hspice shows that the range of oscillation output frequency is 500 kHz-2 MHz, and the offset of oscillator frequency with temperature variation is within ±2.76% when the temperature ranges in -20-＋120 ℃.
出处
《电子元件与材料》
CAS
CSCD
2016年第7期68-71,共4页
Electronic Components And Materials
基金
国家自然科学基金重点项目资助(No.61531016)
国家自然科学基金面上项目资助(No.61271090)
四川省科技支撑计划项目资助(No.2015GZ0103
No.2016GZ0059)
关键词
张弛振荡器
频率可调
低温漂
负反馈
充放电电容
反相器阈值
relaxation oscillator
frequency adjustable
low temperature drift
negative feedback
capacitance of charge and discharge
threshold point of inverter
