Very small step-up transformers?

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http://www.picoelectronics.com/

JF

Some of their parts looked nice... until I looked at the price! $40-60 each? These must be made to order?

-Michael

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They say stock to one week delivery for sample orders, so they
probably don\'t have everything ready to go out the door right away.

They\'ve always been high though, and their stuff _is_ nice. :-)

JF

That's awfully small to work at 10 KHz. We use ISDN line transformers for isolation/stepup at 40 KHz or so, but they're bigger than 1210. But they are cheaper than the Pico stuff, by a factor of 50 roughly.

"Step-up" is a little vague. Can you describe the application better?

John

Do you have any Pico part or series numbers for SMT parts in the .12"x.

10" size range like the OP was wondering about? Smallest I see is grossly larger than that.

Cheers, Tom

What voltage? What source and load impedance? What's the lowest frequency? Do you need isolation, or can it be an autotransformer?

MiniCircuits have some rated down to 4kHz, though not at 9:1 or 16:1 impedance ratio. Don't be put off by the fact they are listed as "single-ended to differential." That mainly means the secondary is center-tapped. Unless you are very concerned about primary-secondary capacitances, exactly how it's wound probably won't matter a lot to you. If isolation isn't important, you can stack the windings and get

3:1 voltage step-up with a 4:1 impedance ratio transformer. Expect some loss, especially operating at the low frequency limit of the part. Note that if you're operating at high impedance, things get worse fast...1000 ohms at 20mA is 0.4 watts, and that's going to be tough. 10 ohms at 20mA is 4 milliwatts, and that you can probably do fine with one of the Minicircuits transformers rated for 50 ohm operation down to a slightly higher frequency.

And...none of these is as small as 1210... Good luck on that one. You could probably get one wound for you, if the voltage is low enough.

Cheers, Tom

Coilcraft has some small coupled inductors with 1:1 ratio, in a 4mm square package

They also have transformers for flyback converters, 4:1 ratio, as small as

12mm square

But 1210 size is 3.2 x 2.5 mm.

They have a 2mm square single inductor

and it looks like it would be possible to add a second winding to make a transformer. Or maybe you could stack a second one on top and get some coupling.

And they have a 5 x 6 mm gate transformer

with 2:1:1 ratio.

There is probably a better way to do whatever it is that the OP requires.

Paul

Google this term:

piezo transformer

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Nemo