On Sun, 3 Nov 2002, Peter L. Peres wrote:

> On Sun, 3 Nov 2002, Jinx wrote:
>
> *>LM317 adj current is only 50-60uA for 10mA < Iout < Imax
>
> Wherever you get that. LM317 adj current is exactly 120uA no matter what
> the load. That's how it comes to set the voltage by using just a resistor.
> Constant current across a resistor == constant voltage == regulation.
> There is only the 1.2V constant voltage between ADJ and Out to be added to
> this.

Ummm...  he got it straight from National's data sheet, page 4 I would
guess.  I just happened to be looking at the LM317 data sheet when this
arrived.  The adj current is specified as 50 to 100uA, and according to
the data sheet the LM317 develops a reference voltage of 1.2 to 1.3V
between the adj pin and the output.

Dale

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads