optical DC/DC step-up converter

Nov 20, 2010 12 Replies

Many years ago I saw an IC that directly converted low voltage DC to higher voltage DC using internal LEDs (no switcher). The theory was that a single LED would shine on a series of LEDs to produce a higher voltage. It was only micropower stuff, but I might have a use for it if I could find it again.



Does this ring a bell to anyone?



Thomas


It does ring a bell but it's been a long time ago and the idea seemed to have vanished quickly, as expected. To me it appeared to be "technology looking for a home".

You can build your own but don't expect any efficiency. Why not use an oscillator and inductors? If it has to be more stealthy maybe use ultrasound and PZT ceramics.

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

But it won't have that slimy green feel ;-) ...Jim Thompson

| James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | If Nancy Pelosi gave Obama one of her balls, they'd both have two.

Toshiba TLP191B. It's an LED illuminating a PV stack. It makes about

10 volts open-circuit on the output side, something like 40 uA short-circuit current.

It's cool for isolated gate drives. You can combine it with a fast AC-coupled drive to get net DC isolated gate drive. I guess you could run some cmos logic, or even a low power uP, from ballpark 200 microwatts.

John

Cool! Avnet has 750 of them, the others seem to be all dry.

At over a buck a pop I'd be partial to using a Chinese-made ferrite-core transformer plus rectifier to get DC up there. At least as long as the Renminbi is pegged against the Dollar :-)

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

Oscillator, transformer, rectifier, filter. That's a lot of parts.

John

International Rectifier PVI5013R does that ; it is a dual in an 8-pin DIP - *but* AFAIK it uses solar cells for the voltage output. But it does put out voltage, so do you care? Gives over 1KV isolation. HexPenSiv; over $6 in onesies..

only

FPGA, uC or DSP pin. As in "free" :-)

30-40c a pop in reel qties. ... That's a lot of parts.

True. Doesn't matter too much but if production has to be domestic with the high placement cost you are right. You'd probably still save with the discrete solution, but not much. In Asia, different thing. I have done designs that are in production there, where some people would scoff of crack jokes about how the world now has ICs and all that. Yet even after years in production there is no way to achieve the same unit price through higher integration.

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

Usually called "Photovoltaic optoisolators".

Am 20.11.2010 03:24, schrieb John Larkin:

and Panasonic APV1121, APV1122, APV2111, APV 2121 max 8.7V, max. 14uA

Martin

Thanks, looks like it might work.

Thomas

Vishay VO1263 kicks the butts of the ones all the other guys mentioned!

_____________________ Mr.CRC crobcBOGUS@REMOVETHISsbcglobal.net SuSE 10.3 Linux 2.6.22.17

"Mr.CRC" wrote in news: snipped-for-privacy@news1.newsguy.com:

Yea that was the best one for the price when I was using them about a year ago. 4 bucks for a dual, you can stack the output and double the output.

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