Abstract
A four-phase, quasi-current-mode hysteretic buck converter with digital frequency synchronization, online comparator offset-calibration and, digital current-sharing control is presented. The switching frequency of the hysteretic converter is digitally synchronized to the input clock reference with less than ± 1.5% error in the switching frequency range of 3-9.5 MHz. The online offset calibration cancels the input-referred offset of the hysteretic comparator and enables ± 1.1% voltage regulation accuracy. Maximum current-sharing error of ± 3.6% is achieved by a duty-cycle-calibrated delay line-based pulsewidth modulation generator, without affecting the phase synchronization timing sequence. In light-load conditions, individual converter phases can be disabled, and the final stage power converter output stage is segmented for high efficiency. The dc-dc converter achieves 93% peak efficiency for Vi= 2 V and Vo= 1.6 V.
Original language | English (US) |
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Journal | IEEE Journal of Solid-State Circuits |
DOIs | |
State | Accepted/In press - Sep 13 2017 |
Keywords
- Auto zero
- current sharing
- dc-dc converter
- digital frequency synchronization (DFS)
- duty-cycle-calibrated delay line (DCC-DL)
- hysteretic control
- multi-phase buck converter
- online offset calibration
- phase synchronization
- quasi-current mode
- switching power supply.
ASJC Scopus subject areas
- Electrical and Electronic Engineering