A digitally controlled oscillator for low voltage energy harvesters

This paper presents the design of a digitally controlled oscillator for low voltage energy harvesters without external components. The performance of the oscillator is verified with simulation results in CSMC 180nm CMOS process. The oscillator operates at a frequency range from 16.5kHz to 82KHz and consumes 85nW at a 1V supply voltage and room temperature, and a temperature coefficient about 172 ppm/°C is achieved over the temperature range of -20°C to 100°C.