23 Oct
2011
23 Oct
'11
3:04 p.m.
On Oct 23, 2011, at 3:44 PM, Benjamin S?lberg wrote:
Why are the LED drivers so difficult to make, is it
because of the 'high' (a few mA) current ?
In the IC world, a few mA is pretty high current. The amount of silicon devoted to making
the I/O pads can actually dwarf the area devoted to the logic on a chip with a lot of
multi-mA I/Os. Even as recently as the '90s, it was a bit of a luxury to drive LEDs
directly from I/O pins (for example, I seem to recall the near-ubiquitous PIC16F84 only
had a few pins capable of that, the rest you'd want to slap a 2N3904 on the output to
drive your LEDs).
- Dave