Digitally controlled PWM buck converter employing counter and VCOs

This paper describes a digitally controlled PWM (DCPWM) buck converter employing a counter and two Voltage Controlled Oscillators (VCOs) for mobile and IoT applications. Employment of the digital counter and two VCOs enables the proposed buck converter circuit to control the duty cycle ratio with high power efficiency. The proposed DCPWM buck converter was fabricated with a CMOS 65 nm standard process. The measurement results demonstrate the wide range of the input and output voltage from 1.0 to 1.5 V and 0.4 to 0.9 V, respectively. The proposed DCPWM buck converter achieved the peak power efficiency of 91% and output ripple voltage of 40 mV at the switching frequency of 1.5-2 MHz and load current range of 30-200 mA.