一种用于锂离子电池管理芯片的时钟产生电路

Clock generation circuit used in lithium-ion battery management IC

设计了一种应用于锂离子电池管理芯片的时钟产生电路．针对应用要求，设计了一个环形振荡器，分析了影响振荡频率精度、输出波形及噪声的因素，并设计了一个无电阻的亚阈值电流偏置电路．电路采用0．6μm UMC数字电路工艺实现．Hspice模拟结果表明：振荡器的输出标准频率为1．975kHz；在各种工艺极限情况下，温度为-40～85℃，电源电压1．5—8V时，振荡频率在1～3kHz间，满足时钟精度要求．典型情况下，该时钟产生电路的电流消耗仅为340—375nA．

A clock generation circuit is presented. Based on the application needs a ring oscillator is designed. Factors that affect the oscillator frequency precision, output wave form and noise are analyzed in detail, and a weak inversion current bias circuit without resistors is designed. The circuit is implemented with 0. 6 p.m united microelectronics corporation （UMC） standard digital process. Hspice simulation results show that the standard frequency output of the oscillator is 1. 975 kHz, and the frequency is within 1 - 3 kHz at all process comers when temperature ranging from - 40 to 85℃ and supply voltage ranging from 1.5 to 8 V. Therefore it can satisfy the high precision needs. Typically, the current consumption of whole clock generation circuit is only 340 to 375 nA.