Common Integrated 3V to 9VDC Converter

Fred Leighton schrieb:

Hello,

3 V is a very uncommon inpult voltage for DC/DC converters. With 5 V instead, you would find a lot to choose from. Some modules will work with 4.5 V.

Bye

Digi-Key has a bunch of dc-dc converter modules. I recently used some from CUI, IIRC. Some are generic enough to be multi-sourced. Your requirements are slightly odd, which limits your choices.

Here's one (3->9v, 1w):

-- Cheers, James Arthur

The old use of such converters was for RS-232 (lots of the transmitter chips needed +/- 9V). That was then, this is now.

If you don't need regulation, PICO sells a bunch of DC/DC converters that are basically a one-transistor oscillator. They have 'em off-the-shelf for higher 'standard' input voltages, but you could buy off-the-shelf and derate it, for your low voltage. Or, ask for custom design.

Sure, a hacked single transistor into a mini toroidal xformer to form a blocking oscillator, with CT in the secondary and you have yourself a simple inverter that can operate all the way down to about 1 volt..

I know, I made some like that, I used zeners instead of diodes on the secondary side to act as both rectifiers and bleeders when voltage exceeded. I simply calibrated the primary side of the oscillator to deliver slightly above needed parameters when loaded. This also helped in cases of unexpected shorts on the output side.

Jamie

Max3232 (3v in) can deliver +/- 7V or 14V single ended, up to around

20mA. Perhaps several of them in parallel for more current.

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The OP spec'd no external parts. Even the modules need caps, though.

-- Cheers, James Arthur