CD54HC670, CD74HC670, CD74HCT670
Test Circuits and Waveforms (Continued)
6ns
6ns
t
6ns
t
6ns
r
f
V
3V
CC
OUTPUT
DISABLE
OUTPUT
DISABLE
90%
2.7
50%
t
1.3
10%
0.3
GND
GND
t
t
t
t
PZL
PZL
PLZ
PLZ
OUTPUT LOW
TO OFF
OUTPUT LOW
TO OFF
50%
50%
1.3V
10%
90%
10%
90%
t
t
PZH
PHZ
PHZ
t
PZH
OUTPUT HIGH
TO OFF
OUTPUT HIGH
TO OFF
1.3V
OUTPUTS
ENABLED
OUTPUTS
ENABLED
OUTPUTS
DISABLED
OUTPUTS
ENABLED
OUTPUTS
DISABLED
OUTPUTS
ENABLED
FIGURE 7. HC THREE-STATE PROPAGATION DELAY
WAVEFORM
FIGURE 8. HCT THREE-STATE PROPAGATION DELAY
WAVEFORM
OTHER
OUTPUT
= 1kΩ
INPUTS
TIED HIGH
OR LOW
IC WITH
THREE-
STATE
R
L
V
FOR t AND t
PLZ
CC
GND FOR t
PZL
AND t
PHZ
PZH
C
L
OUTPUT
50pF
OUTPUT
DISABLE
NOTE: Open drain waveforms t
and t are the same as those for three-state shown on the left. The test circuit is Output R = 1kΩ to
PZL L
PLZ
V
, C = 50pF.
CC
L
FIGURE 9. HC AND HCT THREE-STATE PROPAGATION DELAY TEST CIRCUIT
8
TAOS [ TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS ]
