A Fast Response DC-DC Converter with Programmable Ripple for Combined Distributed Computation and Communication

DC-DC converters with low EMI and fast dynamic voltage scaling capability can significantly benefit the distributed computing and sensing devices in the Internet of things (IoT). However, the classic power converters have to tradeoff between fast transient response and small current ripple. We overcome this limitation by utilizing a programmable saturating inductor. In this paper, we investigate a ripple-programming architecture with compact volume, maximum power consumption of 1% of the power stage, and a ripple settling time below 1ms. The architecture includes a low-cost load estimation method with an error below 8% over the entire load range. We implement this ripple-programming architecture on a 1 MHz constant on-time buck converter prototype with a peak power of 30W. The inductor ripple can be effectively reduced by 40%.