Pro Audio Design Forum

Good point---that is not what I would call red at 605. Yes, the original ref I recall was in a PMI app note, where it was asserted that the red LED (and at the time the only red there was I think) was a close match to a 2N3906 Vbe tempco, given the particular bias conditions they showed fot the 3906...

It's interesting that they found red to be such a low tempco. It must have been a different red (not "standard red") than I've used. It would be costly to use UV LEDs for biasing! But how cool would it be when you are in anot-too-well-lit room and you see things fluorescing when brought ne...