Quote:
Originally Posted by ConnClark
95% or more efficiency is a pipe dream at high current levels and fluctuating loads. In the 11 switchers I have designed the most I got out of them has been 92%. I also had low loss capacitors and low voltage drop diodes and low RDS MOSFETs to work with.
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Most of the losses are on the low voltage side. Using Litz wire, oversizing the windings, and using synchronous rectification all help efficiency. Low switching frequencies also reduce switching losses but increase size of parts.
Getting high efficiency at low voltages is a big challenge. Nonetheless, 95% efficiency is certainly possible at low voltages. The PTV08T250W is 95% efficient when outputting 3.3v at 50A from a 12v supply. Getting that kind of efficiency when outputting 14.4v from a 20v+ source should be a piece of cake by comparison.