Multiple input, single output, single inductor DC-DC converter architecture providing charge reuse by an efficient high voltage current sink

Abstract

Integrated gate-drivers for power MOSFETs require multiple supply voltages biasing internal circuitry or providing a high voltage ground to the high-side driver. This paper proposes a novel DC-DC converter architecture fulfilling these demands of modern gate-driver ASICs while increasing system efficiency. In the proposed concept a conventional single inductor DC-DC converter generating a low voltage supply to auxiliary circuits from a high voltage input is extended by using the high-voltage ground of the gatedriver as an additional input to the converter. This input voltage is controlled to remain nearly constant by adapting its load current with an attached current sink. The charge drained from the high-voltage ground by this current sink is reused to boost system efficiency of the converter. The developed concept is also applicable to converters operating in higher power regimes.