From: "Dmitriy Kiryashov"


> Hi Olin.
>
> CCP pin to base of NPN  ( 2N4401 or 2N2222 , Vcbo about 50v )
> collector to +5v, emitter to current limiting resistor
> 2nd pin of current limiting resistor to anode of LED
> cathode of LED to ground
>
> One resistor less and smaller pcb estate.
>
> Any objections ?
>
>
> WBR Dmitry.
>
> PS. 2N4401 with hFE = 50 on 100 mA sounds scary :)

With an NPN transistor (2n3904, 2n2222 etc), I'd connect the emitter to
ground and the collector to the cathode of the LED.  The LED's anode
should be connected to the dropping resistor and the other end of the
resistor goes to Vcc.  IOW, I'd use it as a low side switch.  I'd
probably use something like a 1K resistor to limit base current.

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