Datasheet

December 1990 5
Philips Semiconductors Product specification
8-input multiplexer; 3-state 74HC/HCT251
DC CHARACTERISTICS FOR 74HC
For the DC characteristics see “74HC/HCT/HCU/HCMOS Logic Family Specifications” .
Output capability: standard
I
CC
category: MSI
AC CHARACTERISTICS FOR 74HC
GND = 0 V; t
r
= t
f
= 6 ns; C
L
= 50 pF
SYMBOL PARAMETER
T
amb
(°C)
UNIT
TEST CONDITIONS
74HC
V
CC
(V)
WAVEFORMS
+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
t
PHL
/ t
PLH
propagation delay
I
n
to Y
50
18
14
170
34
29
215
43
37
255
51
43
ns 2.0
4.5
6.0
Fig.6
t
PHL
/ t
PLH
propagation delay
I
n
to Y
55
20
16
175
35
30
220
44
37
265
53
45
ns 2.0
4.5
6.0
Fig.7
t
PHL
/ t
PLH
propagation delay
S
n
to Y
66
24
19
205
41
35
255
51
43
310
62
53
ns 2.0
4.5
6.0
Fig.6
t
PHL
/ t
PLH
propagation delay
S
n
to Y
69
25
20
205
41
35
255
51
43
310
62
53
ns 2.0
4.5
6.0
Fig.7
t
PZH
/ t
PZL
3-state output enable time
OE to Y, Y
36
13
10
140
28
24
175
35
30
210
42
36
ns 2.0
4.5
6.0
Fig.7
t
PHZ
/ t
PLZ
3-state output disable time
OE to Y, Y
39
14
11
140
28
24
170
35
30
210
42
36
ns 2.0
4.5
6.0
Fig.7
t
THL
/ t
TLH
output transition time 19
7
6
75
15
13
95
19
16
110
22
19
ns 2.0
4.5
6.0
Figs 6 and 7