An architecture of nanosecond level response digital PFM controller for isolated type DC-DC converter

In this paper, a nanosecond level response digital pulse width modulation (PFM) control circuit for the current resonant converter such as LLC has been proposed. The proposed circuit is composed of a unique analog to digital converter and logic based digital controller. With the experimental results, it was confirmed that the switching frequency can be varied from 0.8 to 1.2MHz in regard to 20% variation of the equivalent output voltage of the dc-dc converter. Also, it was confirmed that the time delay can be suppressed to 6.0ns.