Design of Low-power Low-frequency and Fast Start-up Circuit

To overcome the limitation of large power in the complementary metal-oxide semiconductor (CMOS) crystal oscillator circuit of traditional Pierce structure,this paper designed a kind of low-frequency start-up oscillator circuit,which was integrated into the specific non-magnetic meter chip and its frequency was 32.768 kHz.By using the improved push-pull crystal oscillator circuit,the designed circuit could reduce the power effectively and start up quickly.The circuit design,simulation and tapeout had been completed by adopting the Chartered 0.35 μm process model.Test results show that the circuit works correctly,the average operating current is 0.39 μA after stabilization,and the start-up time is less than 200 ms,which meet the system's requirements of frequency and power.