0.8V to 9V supply

[mabauti]

I'm looking for an easy discrete way to convert 0.8V to 9V, I was thinking of 555 as a voltage multiplier but this can be feed down to 1.5V. I need 9V @ 2mA max

thank in advance for your comments/ideas

 

[dknguyen]

Where is 0.8V coming from? I have heard of nothing that runs off of 0.8V...1.2V is the minimum.

From my current knowledge and your current information, I would say it's impossible.

 

[Hero999]

Some DC-DC converter ICs can work from 0.8V, this is the only one that meets the specification I've found so far.

**broken link removed**

You could use a Joul thief style circuit with a zener or a transistor and feedback to limit the output voltage to 9V.

 

[Ubergeek63]

Some DC-DC converter ICs can work from 0.8V, this is the only one that meets the specification I've found so far.

**broken link removed**

You could use a Joul thief style circuit with a zener or a transistor and feedback to limit the output voltage to 9V.

Ouch... my production group would not touch that pachage without death threats from engineering!

http://www.ti.com/lit/gpn/tps61200 will get to 4.5V and a switch capacitor doubler will get to 9V with decent efficiency.

Dan

 

[mabauti]

I'll try those , thank you gents

 

[saturn1bguy]

Ouch... my production group would not touch that pachage without death threats from engineering!

Please elaborate.

 

[dknguyen]

THe package has 7 pads within a spacing of 3mm. All pads are also completely beneath the IC.

 

[Ubergeek63]

Please elaborate.

There are no visible contacts. Add to that the power pad on the bottom of the chip makes it a very difficult chip to work with, bordering on the dificulty level of BGAs.

 

[saturn1bguy]

There are no visible contacts. Add to that the power pad on the bottom of the chip makes it a very difficult chip to work with, bordering on the dificulty level of BGAs.

I presumed by your comments that you were opposed to the LM2623. But it's offered in an 8pin mini-SOIC, so that's obviously not what you were speaking of. Nevermind

 

[Ubergeek63]

I presumed by your comments that you were opposed to the LM2623. But it's offered in an 8pin mini-SOIC, so that's obviously not what you were speaking of. Nevermind

Ah so it is, I missed that one, a bit tight for hobbyist hand soldering but no where near the nuisance of the other package.

That would make my only complaints about it that it is not a synchronous rectifier and that there is the chance that it will not start at the stated 0.8V in. It's max start up voltage is 1.1V with a negative temperature coefficient.