Design of a Low Power and Wide Frequency Range Ring VCO

This paper proposes a low-power, wide frequency range ring VCO circuit structure based on the application of switch power supply modulation technology. Circuit simulation is completed based on CMSC 180nm BCD process. Simulation results show that the VCO circuit can work at a power supply voltage of 3-5 V, and it has a relatively wide frequency range. Under a 5V power supply voltage and a control voltage range of 4.2V~2.2V, the output frequency range is 0.4-11.96MHz. Under a 3V power supply voltage and a control voltage of 2.2V~0.2V, the output frequency range is 0.56~12.3MHz. For the VCO circuit, the maximum average working current of the power supply is less than 80uA, and the average current of the power supply is only 35uA under a 5V power supply voltage and a 10MHz working frequency. The VCO circuit meets the requirements of low power consumption. It can be applied to switch power supply chips.