Philips Semiconductors
Product specification
74F257A
Quad 2-line to 1-line selector/multiplexer, non-inverting
(3-State)
1995 Mar 31
6
AC WAVEFORMS
For all waveforms, V
M
= 1.5V.
VM
VM
VM
VM
Yn
In or S
tPHL
tPLH
SF00679
Waveform 1.
Propagation Delay, Data and Select to Output
VOH–0.3V
VM
VM
VM
Yn
tPZH
tPHZ
SF00213
OE
0V
Waveform 2.
3-State Output Enable Time to High Level and
Output Disable Time from High Level
VOL+0.3V
VM
VM
VM
Yn
tPZL
tPLZ
SF00214
OE
Waveform 3.
3-State Output Enable Time to Low Level and
Output Disable Time from Low Level
TEST CIRCUIT AND WAVEFORMS
tw
90%
VM
10%
90%
VM
10%
90%
VM
10%
90%
VM
10%
NEGATIVE
PULSE
POSITIVE
PULSE
tw
AMP (V)
0V
0V
tTHL (tf
)
INPUT PULSE REQUIREMENTS
rep. rate
t
w
t
TLH
t
THL
1MHz
500ns
2.5ns
2.5ns
Input Pulse Definition
VCC
family
74F
D.U.T.
PULSE
GENERATOR
RL
CL
RT
VIN
VOUT
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.
tTHL (tf
)
tTLH (tr
)
tTLH (tr
)
AMP (V)
amplitude
3.0V
1.5V
V
M
RL
7.0V
SF00777
TEST
SWITCH
t
PLZ
closed
t
PZL
closed
All other
open
SWITCH POSITION
