[sdiy] Op Amp LED driver / Current Source problem/solution

[Neil Johnson]

Tim Ressel wrote:
> I am wondering if an inverting circuit work better:
> http://www.sdiy.org/brotheo/LedDriver.png
>
> You probably still need a resistor to null the DAC offset at zero output.

Umm, the problem with that circuit is that the input also supplies the
LED current, so you are loading the signal you are monitoring.  Not so
good for LEDs that take lots of mA.

Neil
--
http://www.njohnson.co.uk