3.3V - An easier source.

[khaag]

I believe I have stumbled upon another option for obtaining 3.3V. There is a simple 3-pin regular made exactly for this purpose. No capacitors, no resistors, just a simple regulator in the exact same format as everybody's favourite 7805. It's an LM3940 and it's made by National Semiconductor.

Whatd'ya know, they offer free samples too.

[robm]

The only thing I came up with was an "audio" amplifier, the LM384.


If it's the same unit you were looking at, I think the input voltage might be a problem with the input voltage - lists minimum at 12v.

[Skyone]

@robm: http://www.national.com/mpf/LM/LM3940.html

Maximum input is 7.5v, which is just teetering above the 7.2v standard a lot of us would use for the N64 (7.2v battery packs rise to a maximum of 9.0v on a full charge). Also, I don't think 1A is enough for power the the 3.3v line on the N64.

[Kyo]

I found one too, which I haven't tested yet, and not looked into the datasheet, but: LF33CV

I saw this at my supplier, so I bought one. I also bought some LM317 which has:
Output Current 1500, 1000, 500 mA
Input Min Voltage 4.2 Volt
Input Max Voltage 40, 37 Volt

[marshallh]

If you're going to use that, might as well use an LM7833 which doesn't have the max. voltage limit.

Either way, a linear regulator wastes power and getting/building a switching regulator is the way to go. Even if you have to (gasp!) look at the reference design in the datasheet and build a little PCB.

BTW, if you need something adjustable like the LM317 but with more current, try the LM350.

[Kyo]

I got what was available to me. My store doesn't carry the LM7833, but 42V is ridiculously high anyway. I didn't get these for a specific project, I just think it's good to have some around. If I ever decide to make a portable that needs 3.3 (or 1.9), I'll probably get a switching regulator. (Especially as those projects use up more A!)

[ShockSlayer]

So?

TI regulators still win, and a resistor and a capacitor is not that hard to find.

SS