L

#### little billy

- Jan 1, 1970

- 0

in the manual of the lm317 page 16

http://www.national.com/ds.cgi/LM/LM117.pdf

Assuming we have a load RL from the output to ground

can we say the following:

IL = Vo/RL where Vo = output current, IL = load current

Denote the constant current of the regulatror as C

C = Ic + IL , where Ic = collector current

Ic = Ib * beta hence Ic = Vi/R1 * beta where Vi = input voltage

all of this gives us

(Vo/RL) + (Vi/R1)*beta = C

what is the gain ?