高精度高性能晶体振荡器电路

Design of crystal oscillators with high precision and performance

设计了一种用于实时时钟的高精度高性能晶体振荡器．采用振幅控制机理以达到高频率稳定性和低功耗的要求。基于外部电容调谐的原理来进一步提高实时时钟精度．电路在0．6μmCMOS工艺上实现，测试结果表明在工作电压为3V的条件下，振荡器的工作电流小于240nA，振荡器能够稳定工作在1．5～5．5V的电压范围。时钟精度可达5．8×10^-6．

A crystal oscillator with high precision and performance for real time clock （RTC） is designed. An amplitude regulation scheme is used to achieve high frequency stability and low power consumption. The theory of tuning capacitor is analyzed to improve the RTC precision. A practical circuit is implemented on 0.6/lm CMOS process. The test results showed that the supply current of the crystal oscillator is less than 240 nA when the supply voltage is 3 V. The supply voltage of the oscillator is stable at the ranges of 1.5-5.5 V, and the precision of the clock is up to 5.8×10^-6.