Charge recovery in power converter driver stages

Abstract

A power converter includes a first transistor operable to source current to a load when switched on, a second transistor operable to freewheel inductor current or sink current from the load when switched on, and a driver circuit. The driver circuit is operable to switch the first transistor on and the second transistor off during a first period, switch the first transistor off and the second transistor on during a third period after the first period, and connect a gate of the first transistor to a gate of the second transistor during a second period between the first and third periods when the gates of both transistors are floating.

Description

technical field [0001] The present application relates to power converter driver stages, particularly charge recovery in power converter driver stages. Background technique [0002] Switching power converters are widely used in high power applications due to their high efficiency and small size. Converter efficiency is increasingly important at low and medium power levels. For example, buck converters are particularly well suited to supply high current at the low voltages required by state of the art high performance integrated circuits such as microprocessors, graphics processors and network processors. Typically, active components such as pulse width modulation controllers (PWM), drivers, power MOSFETs (metal oxide semiconductor field effect transistors) and passive components such as inductors, transformers or coupled inductors, capacitors and resistor) to implement a buck converter. [0003] Most traditional buck converters use direct drive to turn on the MOSFETs of t...

AI Technical Summary

Problems solved by technology

Typically, the energy used for the gate drive process is then dissipated

Some conventional approaches try to recover a portion of the gate drive energy by storing energy in an external capacitor, which adds complexity to the driver as additional pins and external components are required

The storage capacitor could instead be integrated in the driver, but doing so increases the size and cost of the driver circuit

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