Phase Offset Compensation for Multiphase DC-DC Converter

摘要

The present document relates to multiphase DC-DC power converters. In particular, the present document relates to the compensation of the phase offset incurred in multiphase DC-DC power converters which are controlled based on coil current zero crossing. A control circuit for a multiphase power converter is described. The multiphase power converter comprises a first and a second constituent switched-mode power converter, wherein the first and second constituent power converters provide first and second phase currents, respectively. The first and second phase currents contribute to a joint load current of the multiphase power converter. The first and second constituent power converters comprise first and second half bridges with first and second high side switches and first and second low side switches, respectively.

主权项

1) A control circuit for a multiphase power converter; wherein the multiphase power converter comprises a first and a second constituent switched-mode power converter; wherein the first and second constituent power converters provide first and second phase currents, respectively; wherein the first and second phase currents contribute to a joint load current of the multiphase power converter; wherein the first and second constituent power converters comprise first and second half bridges with first and second high side switches and first and second low side switches, respectively; wherein the control circuit is configured to
operate the first and second constituent power converters in a pulse width modulation (PWM) mode with a constant commutation cycle rate; operate the low side switches in a complementary manner with regards to the respective high side switches; detect a zero crossing of the first phase current at a first time instant, when the first high side switch is in off-state; and operate the first low side switch as an active diode, upon detecting the zero crossing of the first phase current.