0.13 μm Low-Power CMOS Current Starved VCO for Vibration Energy Harvesters

This work presents a current starved voltage-controlled oscillator (VCO) based on the standard 0.13- μm CMOS process. Incorporated with the power management circuit (PMC), the current starved VCO generates an average periodic signal at a frequency of 84.81 kHz. In addition, to assure that the VCO has a stable periodic signal output regarding the varied control voltage, a voltage reference is realized. The proposed architecture makes full use of subthreshold and deep triode MOSFETs without any other components. A reference voltage of 258.35 mV is obtained in response to the supply voltage 1.0-3.2 V. The architecture exhibits a linear sensitivity of 0.49%/V at 27 °C. Power consumption of the proposed circuit is 3.546 μW at 3 V of the voltage supply. The output of the architecture leads to a time-control local oscillator, which can be employed in a PMC for vibration energy harvesters.