Philips Semiconductors
Product specification
Octal buffers (3-State)
74F244/74F244B
AC WAVEFORMS
For all waveforms, V
M
= 1.5V.
Ian, Ibn
V
M
V
M
t
PHL
Yn, Yn
V
M
t
sk
(0)
t
PLH
Yn
V
M
V
M
Yn, Yn
V
M
SF00231
SF00232
Waveform 1. Propagation Delay for data to outputs
Waveform 3. Output skew
OEn
V
M
V
M
OEn
V
M
t
PZL
V
M
t
PLZ
3.5V
t
PZH
t
PHZ
V
OH
–0.3V
Yn
0V
Yn
V
M
V
M
V
OL
+0.3V
SF00233
SF00234
Waveform 2. 3-State output enable time to high level
and output disable time from high level
Waveform 4. 3-State output enable time to low level
and output disable time from low level
TEST CIRCUIT AND WAVEFORMS
SWITCH POSITION
TEST
SWITCH
t
PLZ
, t
PZL
closed
All other
open
V
IN
PULSE
GENERATOR
R
T
D.U.T.
t
TLH (
t
r
)
C
L
R
L
POSITIVE
PULSE
10%
90%
V
M
t
w
t
THL (
t
f
)
AMP (V)
90%
V
M
10%
0V
V
CC
7.0V
90%
NEGATIVE
PULSE
V
M
10%
V
OUT
R
L
t
THL (
t
f
)
t
w
V
M
10%
t
TLH (
t
r
)
0V
90%
AMP (V)
Test circuit for 3-State outputs
DEFINITIONS:
R
L
= Load resistor; see AC electrical characteristics for
value.
C
L
= Load capacitance includes jig and probe
capacitance; see AC electrical characteristics for
value
R
T
= Termination resistance should be equal to Z
OUT
of
pulse generators.
Input pulse definition
INPUT PULSE REQUIREMENTS
family
amplitude
74F
3.0V
V
M
1.5V
rep. rate
1MHz
t
w
t
TLH
t
THL
2.5ns
SF000235
500ns 2.5ns
1994 Dec 5
7
PHILIPS [ NXP SEMICONDUCTORS ]
