Hi, i am trying to step down 12v to 3.3v. I have two different 3.3v regulators i have tried (1.5a and 3a) and all i ever get out according to my voltmeter is 0.01v. I have tried a 5v reg and it works fine. Whats going on?
The part numbers are LM1085IT-3.3 and LM1086CT-3.3
Hi, i am trying to step down 12v to 3.3v. I have two different 3.3v regulators i have tried (1.5a and 3a) and all i ever get out according to my voltmeter is 0.01v. I have tried a 5v reg and it works fine. Whats going on?
The part numbers are LM1085IT-3.3 and LM1086CT-3.3
Are you wiring them the correct way?, regulators often have different connections. I'm presuming you also have the required capacitors on the input and output?, instability could stop it working.
As I see it there are only two possibilities?, either it's wired incorrectly, or you have faulty components somewhere - possibly both chips are faulty? (which seems highly unlikely). Another possibility is an external component, the 47uF S/C would probably cause this as would anything S/C on the output.
Is the chip mounted on a heatsink?, if so, is it insulated from the heatsink?.
It's a simple enough circuit, there's not many possibilities.