At 12:57 PM 1/12/2014, you wrote:
>Hi all,
>
>Haven't started the experiments yet, but I have new information that
>might change things.
>
>It turns out that all I will need to control for this version are a
>bank of up to 3 Superflux LEDs. Total draw, under 0.2A (generously,
>I'm looking to run them closer to 150mA, and I'd guess even that will
>be too bright).
>
>I am also having some spacing issues jamming the TO-220 packages into
>the enclosure.
>
>Remember when I said the board already had provision for a transistor
>on it? Well, I found this part:
>http://www.digikey.ca/product-detail/en/SSM3K333R,LF/SSM3K333RLFCT-ND/3522=
391
>(a Toshiba SSM3K333R) in SO23 that would match the footprint already
>on the board. I'd have to scab on a pull up resistor, but that
>wouldn't be too bad. Gate resistor already has a footprint.

Hi, Josh:-

All the SOT-23 parts tend to have the same pinout.

The IRLML6344TRPbF is a 30V part .. Rds(on) 29m ohm with 4.5V drive
and 37m ohm max with 2.5V drive. Only CAD 19.7 cents if you buy
$10 worth, so less than half the price of the SSM3K333R for better
performance. About double the gate charge, so not everything is free.

I tend to pick parts that have wide applicability in ones-y twos-y
situations so that the same P/N can be used in the future- so being
able to drive it full on with a 3V supply can help with that.

--sp


>Any thoughts? It sets me back a bit as I'll have to wait until Tuesday
>to get the parts, but might be worth it given how much time I've been
>staring at the enclosure trying to figure out to squeeze things in
>there in a way that isn't horrible.
>
>Josh
>--
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