Lm317 input current VS output current

[Asim]

Hello all

My question is if i supply the regulator with 500 mA ( as an example) what is the maximum output current I can get? Or there is no current losses? And of there are ,how much losses ?


Thanks

[Simon]

linear regulators use around 5mA for themselves (quiescent current on the datasheet) the rest is yours, linear regulators are like an automatic variable resistor and can't ever give out more current than comes in.

[Asim]

linear regulators use around 5mA for themselves (quiescent current on the datasheet) the rest is yours, linear regulators are like an automatic variable resistor and can't ever give out more current than comes in.

Alright , thanks 

[David Hess]

A floating regulator like the LM317 only uses about 5 microamps for itself which is lost through the adjustment pin.  Most of its quiescent current flows to the output so it is available to the load which explains why it has a minimum load requirement of somewhere between about 1 and 10 milliamps.

The quiescent current for a 7805/LM340 flows out the common pin and is unavailable to the load.

[Dave]

Datasheets, people.

[David Hess]

I was going by memory.

Check out the common pin current on a 7805.

[Simon]

does it matter ? we are talking no more than 5mA and if that it going to make a difference when your drawing 100's of mA then something is wrong.