Integrated Gate Drive Architecture for High Step-down Multiphase Buck Converter

Konferenz: PCIM Europe 2015 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management
19.05.2015 - 20.05.2015 in Nürnberg, Deutschland

Tagungsband: PCIM Europe 2015

Seiten: 8Sprache: EnglischTyp: PDF

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Autoren:
Calabrese, Giacomo; Capineri, Lorenzo (Universita degli Studi di Firenze - DINFO, Italy)
Granato, Maurizio; Frattini, Giovanni (Texas Instruments Italia, Italy)

Inhalt:
Point of load DC-DC multiphase buck converters operating with high step-down conversion ratios work with narrow duty cycles. So-called “high step-down multiphase buck” topologies present advantages in terms of extended duty cycle, reduced passive components’ size and reduced switches’ breakdown voltages. However, these topologies require a more complex gate drive structure for their high side switches which are working each on a different voltage domain. A common approach is based on a cascade of bootstrap drivers. This solution requires a dedicated voltage source usually working at a voltage lower than the input one. The proposed drive architecture eliminates the need of this additional voltage source being directly supplied on fractions of the input voltage. It also provides a recycling of the gate charge at the turn-off of the switches. Its behaviour is demonstrated by an integrated implementation together with the power stage switches of a high step-down four phases buck converter switching at 10 MHz. Power stage measured waveforms show the correct operation of the proposed design of the drive architecture.