A 4 MHz digital single inductor dual outputs buck/boost DC-DC converter with 10-bit ΣΔ digital pulse width modulation

A 4 MHz monolithic digital single-inductor dual-output (DSIDO) buck/boost converter based on 10-bit ΣΔ modulator and 4-bit delay line digital pulse width modulator (DPWM) is presented. Window delay line ADCs, digital PID compensator and DPWM with 2
^nd
ΣΔ modulator are utilized in the converter to pursue highly flexible and intelligent power management. Digital Extend PWM control method is proposed to the converter which is implemented in 0.35μm CMOS process. Measurement results show the converter can work in buck mode, boost mode and buck/boost mode. The converter has a peak efficiency of 83% while offers 400mA current to the load. And the outputs voltage ripples are less than 47mV both in buck and boost mode.