5V - 40V - 5V step up and down converters

Leo Chang1

Need to transmit 10W power over thin wire. The plan to step up on transmit end and step down at the receiver end. Requirement:

Transmitter: 5V/10A step up to 40V/0.25A over the wire. (Slightly higher or lower is fine on high voltage end.)

Receiver: 40V/0.25A wire step down to 5V/7A (some loss in conversion and transmitting).

Isolation is not necessary.

Looked at some TI/NSC parts, but did not find reference designs. Could you please *recommend some parts* and *application reference notes*? (Notes on efficiency optimized for the current consumption.)

Thanks, //Leo

over 12 years ago

0 Donald Jones over 12 years ago

TI__Mastermind 22610 points

" ... 40V/0.25A wire step down to 5V/7A (some loss in conversion and transmitting). ..."

If you need 35W at the output, and are using 40V on the intermediate transmission (thin) wire, then the thin wire need to carry at least 1.1A assuming ~80% efficiency in the buck conversion back down to 5V/7A (44W in x 80% = 35W out)

0 Leo Chang1 over 12 years ago in reply to Donald Jones

Prodigy 30 points

Sorry, it should be 5V/1.4A 7W at the receiver end. So carrying 0.25A on the thin wire. Thanks for the reply.

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5V - 40V - 5V step up and down converters