Design of high accuracy high conversion ratio single-stage switching power converter for modern FPGAs at 10MHz

With a significant input-to-output conversion ratio from 12V to 1V, single-stage DC-DC conversion solution has obvious benefits on efficiency and cost, compared to the cascaded counterparts, but is generally difficult to control and thus suffers from large regulation inaccuracy. To mitigate these issues, this paper presents a single-stage, adaptive on-time (AOT) hysteretic controlled converter. In this converter, a V
_O
error compensation technique is proposed to adaptively update a controllable reference voltage for accurate V
_O
regulation. In the meantime, a sub-ns delay high voltage level shifter for high side power switch is designed to facilitate high frequency operation at high conversion ratio (CR). With a 12V-to-1V CR, the proposed converter only experiences a V
_O
undershoot/overshoot of 28mV/34mV to a load change of 3.5A within 200ns. In particular, 501ps and 751ps propagation delay for up- and down-level shifting are achieved, respectively. Thanks to the V
_O
error compensation, 0.06mV/V line regulation and a 0.15mV/A load regulation are achieved. It achieves a maximum efficiency of 84.6% at 10MHz.