HV piezo supply recomendation

[grouchobyte]

One of my consulting clients needs a very compact and very low current supply for a piezo-driven optical scanner in a medical probe. We need about 150 volts and less than 2 mA from a DC source like under 12 volts. The formfactor must be small and this solution is too large

http://www.xppower.com/Portals/0/pdfs/SF_AG_Series.pdf?ver=2016-07-22-085731-773

I can design a cockcroft multiplier but I am not  sure I can get the total volume solution any lower

Any ideas?

@grouchobyte

[Someone]

Before looking at the link I imagined how small I could squeeze such a specification, not much smaller than they have. Anything under 400V is usually easier and can be done in a direct boost if you don't mind the noise or use a tiny coupled inductor, and while getting to half their size is possible, a quarter would be very hard.

[grouchobyte]

They give some suggestions for some pretty small flyback transformer solutions in this DS:
http://www.linear.com/product/LT3485

Coilcraft has some semi-small transformers for such general kinds of ICs though IIRC some of the transformers listed in the above LT DS were a bit smaller:
http://www.coilcraft.com/cj5143.cfm
The Coilcraft DS also references an ON-Semi capacitor charger IC of some sort on that coilcraft page so ON may have some competitive parts.

evb149

Thanks for your posts. Seems you've been down this path before. The project I am doing consulting work on is confidential and I have signed an NDA on it so I am sworn to secrecy since its a patented medical device we are trying to commercialize and miniaturize. I will review some of these suggestions and possible try some of them out in the lab. 

@grouchobyte

[eliocor]

Maybe you can use the following transformers (1:10): TDK ATB3225: they are rather small.
They are even not too expensive: http://www.digikey.com/product-detail/en/tdk-corporation/ATB322524-0110/445-8636-1-ND/3008154
followed by 1 stage multiplier the complete power supply should not require too much space.

[daqq]

You can get really small with a boost DC DC converter, perhaps with an external transistor.

See the UC3845B ( http://www.st.com/content/ccc/resource/technical/document/datasheet/b6/e8/cc/ba/4f/cd/42/9b/CD00000966.pdf/files/CD00000966.pdf/jcr:content/translations/en.CD00000966.pdf ) - I used it for the same purpose recently - get +250V @ 6W from a +12V DC source. I just added an external transistor, caps, inductor, diode and the proper feedback divider. There are other, similar ones out there.

[mikeselectricstuff]

You'll probably struggle to get much smaller than a commercial DC-DC unless your output requirement is a lot lower than the nearest model.
Look at (magnetics for) supplies for electroluminescent displays which are in a similar ballpark voltage-wise.
Small DC-DCs tent to use high frequencies ( low MHz) but this gets less practical at higher voltages due to capacitive losses.