I've strangely noticed that my voltage regulator doesn't seem to work under low current loads . . . Meaning, if I don't connect a few LED's to the power line, my microcontroller just doesn't work . . . so confusing!
I design my circuit to be ultra efficient, and it rebels at me!
Anyway, I always thought regulators just 'always worked' but apparently not . . .
This is what I am using: L4940V5http://www.st.com/stonline/books/pdf/docs/2141.pdf
So, I'm guessing I should throw a resistor or LED between output and ground to fix it . . . so how do I calculate this resistor value?
Looking at the datasheet, I see something called ''quiescent current" . . . google and wikipedia don't know what it is, but I found something that said:
"The operating point of a device, also known as bias point or quiescent point (or simply Q-point), is the DC voltage and/or current which, when applied to a device, causes it to operate in a certain desired fashion."
The datasheet says 90mA is required . . . what a waste of power! If this is correct, I would need 5V/.09A= 55ohms . . . hmmm feels like I'm shorting something . . .
Am I on the mark here or totally confused?