Hi all,
I'm trying to keep an LED lit to a fair amount of accruacy at ~100uA. Right now, I'm just using a 5V rail, LED, and resistor. However, I'm concerned that there will be device to device brightness bariation doing this, due to variable Vf of the LEDs.
Does anyone have a good idea for a cheap / low part count solution? I'm mulling using a mosfet current mirror / Widlar current source, but I'm concerned that mosfet mismatch is going to be a problem doing this.
I don't need super accurate -- 10% variation is fine.
Suggestions?