#garfield Logs

Mar 10 2023

09:03 PM aandrew: blah
09:14 PM aandrew: I'm having a major brain fart
09:14 PM aandrew: I have a 3.3V logic signal. It's connected to the shutdown pin on a 5V part. The Vih is perfectly fine, no worries there.
09:14 PM aandrew: this signal has a 10k pull down so the shutdown input is active when I don't have it connected to anything
09:14 PM aandrew: I want to turn an amber LED *on* when the signal is low and off when it's at 3.3V. The V+ for the LED is 5V
09:14 PM aandrew: first attempt would have been to just use a PNP transistor but the 3.3V logic signal means that the transistor is always biased on enough to drive the LED. Same with a P channel mosfet
09:14 PM aandrew: I can get around this with an nch+pch but I don't want to use two parts, I want to use one