2 Jul
2012
2 Jul
'12
2:32 p.m.
> The Input is showing 330 Ohm to GND and 327 Ohm
to VCC. The Output has
> no measurable Ohm, neiter to VCC, nor to GND.
Does 'n measurable ohm' mean a short (0 ohms) or open (infinte,
overrange, etc)?
Unless there's an external pullup resistor, I can't imagine that this
is an OC output or that the drive is capacitively coupled Did you
try the diode (high voltage) setting on your ohmmeter?
If the otuptu is a totem pole circuit, or a PNP/NPN complementary driver
with no pull-up resisotrs, and built from discrete compoennts so no
parasitic diodes, is it certain that an ohmmeter iwll turn on at elast on
of the transisotrs? I don't think it is.
-tony