[sdiy] 3.3V regulator ?

[Barry Klein]

the lm317 has too high of a dropout voltage if you plan to run off the 5V
source.

-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Roman
Sent: Tuesday, February 10, 2004 2:38 AM
To: Linium
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] 3.3V regulator ?


use LM317 and 2 resistors, dirt cheap.
you can find all the info and how to calculate resistors in datasheet (I
hope).
Or go to National Semi website and choose one of large variety. They have
decent parametric search.

Roman

---- Wiadomość Oryginalna ----
Od: Linium <intent at netpratique.fr>
Do: diy <synth-diy at dropmix.xs4all.nl>
Data: Mon, 9 Feb 2004 18:08:46 +0100
Temat: [sdiy] 3.3V regulator ?

>Hello,
>
>I need a 3.3v regulator for a DIR1703 (a spdif->i2s/serial convertor made
by 
>Texas Instrument). The problem is i don't find this kind of regulator. The 
>circuit board will have this chip and a DAC plus minor parts and that's
all. 
>The DAC needs 5V, and only the DIR1703 needs 3.3V.
>
>I know this kind of regulator does exist but simply are hard to find, i was

>wondering about alternatives.
>
>Given that the DIR1703 needs around 50mA for its power and that i don't
need 
>top notch parts since the DAC will be used for DC signals, can i :
>
>-use a divider bridge with resistors from the 5V power line to make 3.3V 
>-use a AOP for the same kind of thing (problem the supply will be 0-5v)
>-use a regulator with variable voltage out, i just discover this
possibility, 
>there seems to have some regulators that can be "tuned" with a resistor to 
>produce a voltage in a given range. I don't know at all if they are good or

>what.
>
>Thx,
>
>Linium
>
>