(Adding EE tag)

Gordon Williams wrote:
> I'm looking for suggestions for common a jellybean 3.3 v regulator.  Max
>  dropout voltage 0.3 volts at 200 mA.

Here are my current favourites --

Not the cheapest (about =A31 each), but pretty beefy:
   ON Semiconductor NCP565D2T33G -- 1.5A, 3.3V, TO263-3 (D2PAK) package

Less powerful but much cheaper (about 30p each) and smaller:
   Zetex ZXCL330E5TA -- 150mA. 3.3V, SOT23-5 package

If you want something in the middle, there's the National Semiconductor =

LDO range. The LP3982 series might be worth looking into -- =

LP3982IMM-3.3 is 3.3V, 300mA output, 0.12V dropout. Cost about 50p each =

in 10-off.

 > I'm looking for something that is
> stable with ordinary ceramic caps on input and output. Power dissipation =
0.5
> W max.  Should have thermal shutdown, short circuit, reverse battery
> protection, etc.

I've used the ZXCL series with SMD ceramics, so that's not a real issue. =

I think the datasheet actually tells you to use ceramics over anything =

else (better ESR or something like that).

Over-temperature shutdown is more or less standard these days, but don't =

expect an LDO of this class to have reverse-polarity or over-voltage =

protection. These can be added with a Schottky diode -- 1N5817 or =

similar, fitted on the input (anode to ground, cathode to V_in).

It's also worth adding a diode between output and input (anode to =

output, cathode to input). This extends the life of the LDO by =

preventing charge in the output capacitors from trying to blast its way =

through the FETs / BJTs in the regulator. IIRC it's "highly recommended" =

in the Zetex datasheet, and "suggested" by ONSemi.

-- =

Phil.
piclist@philpem.me.uk
http://www.philpem.me.uk/

-- =

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