Test Load Circuit - Intel 80960KB Manual

80960KB
of a matched diode bridge. Since the open-drain
outputs sink current, only the I
are necessary and the I
OH
the 80960KB driver under test is turned off, the
output pin is pulled up to V
is turned off and the I current source flows through
OL
diode D .
2
When the 80960KB open-drain driver under test is
on, diode D is also on and the voltage on the pin
1
being tested drops to V
OL
flows through diode D .
1
14
legs of the bridge
OL
legs are not used. When
(i.e., V ). Diode D
REF OH
. Diode D turns off and I
2 OL
THREE-STATE OUTPUT
1
C = 50 pF for all signals
L
Figure 12. Test Load Circuit for Three-State
OPEN-DRAIN OUTPUT
C
L
C = 50 pF for all signals
L
Figure 13. Test Load Circuit for Open-Drain
C
L
Output Pins
I
OL
D
D
2
1
I Tested at 25 mA
OL
V = V
REF CC
D1 and D are matched
2
Output Pins