A VHF-level fully integrated multi-phase switching converter using bond-wire inductors, on-chip decoupling capacitors and DLL phase synchronization

Abstract

This paper presents a fully integrated, four-phase, DC-DC switching converter with fast transient response. By applying effective clock and phase synchronization schemes to a current-mode hysteretic control, the multiphase converter achieves ripple cancellation and fast transient response seamlessly. Thanks to the very high frequency (VHF) operation (200 MHz) and the multiphase interleaving topology, the inductance and the capacitance in the power stage are reduced significantly, allowing the use of bond-wires as main inductors and all fully on-chip capacitors. The output voltage of the converter can be regulated at any level between 0.6 V and 0.9 V, with an input source of 1.1 V. The converter achieves 89% maximum efficiency at 170 mW and 79% efficiency at the full load of 540 mW. The transient response times from no load to 300 mA are within 10 ns with 8.8% voltage droop (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OUT</sub> =0.9V).