AN2530 Datasheet, PDF (1/13 Pages) STMicroelectronics – Solution for 150 W half bridge resonant DC-DC converter

AN2530
Application note
Solution for 150 W half bridge resonant DC-DC converter
Introduction
This application note describes a 150 W Half bridge resonant DC-DC converter. This type of
SMPS is highly attractive due to its high achievable efficiency, very low noise and compact
size.
Resonant converters are among the least common SMPS topologies. There are several
reasons why they are not often used, but we will not discuss these reasons in this
application note. However, it is worth noting that the resonant topologies have undeniable
advantages over the "hard switching" topologies. The very high achievable efficiency of over
90% and up to 95% is very common, as well as their low generated noise due to ZVS (zero
voltage switching) and resonant energy transfer.
Other related advantages derived from these converters are their compact size due to their
need for smaller power switches (Power MOSFETs usually), smaller transformers, and less
generated heat (the lower losses are a part of this). Less heat means a smaller heat sink
and a longer life for power components.
If the necessary care is taken in the design phase, the results are very good and the typical
issues normally associated with these topologies are avoided.
ST's L6598 half bridge driver has been chosen for this design. Please refer to the L6598
datasheet for full specifications and capabilities, or to other documentation, application
notes and books where it is used, in order to have the best picture of this design. All
references are provided in Figure 7.
This application note concentrates only on the power aspects, because as already
mentioned, there are excellent guides for the driver (aside from the datasheet) as well as
application notes for SMPS in general, magnetics, topologies, etc.
October 2007
Rev 1
1/13
www.st.com