23 Oct
2011
23 Oct
'11
5:39 p.m.
Why are the LED drivers so difficult to make, is it
because of the 'high' (a few mA) current ?
Most of the handheld devices of the 70's used multiplexed displays (well, still true
today) and while the average LED current might be a few mA per segment, the peak current
in the drivers could be ten times higher.
Some of the intended-to-be-driven-by-PMOS-driver-chips of the 70's are still around
today and put to other good uses. e.g. ULN2002.