一种宽温度范围电流恒定电荷泵

A wide temperature range constant current charge pump

针对传统电荷泵的输出电流随温度发生较大变化引起锁相环的环路带宽和峰峰值抖动周期发生较大波动的问题,设计了一种新型电荷泵。通过引入一种温度检测和补偿电路,补偿电荷泵电流随温度发生改变的问题,保证在不同温度下电荷泵输出电流保持相同,达到了稳定锁相环峰峰值抖动周期的目的。基于TSMC 0.18μm CMOS工艺,利用Cadence软件完成了电路的设计与仿真。结果表明,该电荷泵在-40~100℃范围内输出电流可以基本稳定在100μA,电流偏差为2μA,电流匹配范围为0.3~1.6 V,失配率为1.6%。

A novel charge pump was designed to resolve the problems of the output current of traditional charge pump varies greatly with temperature,which results in large fluctuation of loop bandwidth and peak-peak jitter of PLL.A temperature detection and compensation circuit was introduced to compensate the problem of charge pump current vary with temperature,guarantee the charge pump have the same output current at different temperatures,the aim of stabilizing peak-to-peak jitter of PLL is achieved.Based on the TSMC 0.18μm CMOS process,the novel charge pump was designed and simulated by Cadence.The results indicated that the output current of the charge pump can be basically stabilized at 100μA when the temperature in the range of-40~100℃,the current offset is 2μA,the current matching range is 0.3~1.6 V,and the mismatch rate is 1.6%.