HD74HC251 Datasheet, PDF (5/9 Pages) Hitachi Semiconductor – 1 of 8 Data Selectors/Multiplexers (with 3-state outputs)

HD74HC251
Switching Characteristics
Item
Symbol V_CC (V)
Propagation delay tPLH
2.0
time
t_PHL
4.5
6.0
t_PLH
2.0
t_PHL
4.5
6.0
t_PLH
2.0
t_PHL
4.5
6.0
t_PLH
2.0
t_PHL
4.5
6.0
Output enable time t_ZH
2.0
t_ZL
4.5
6.0
t_ZH
2.0
t_ZL
4.5
6.0
Output disable
time
t_HZ
2.0
t_LZ
4.5
6.0
t_HZ
2.0
t_LZ
4.5
6.0
Output rise/fall
time
t_TLH
2.0
t_THL
4.5
6.0
Input capacitance Cin
—
Ta = 25°C
Min Typ Max
— — 205
— 20 41
— — 35
— — 205
— 20 41
— — 35
— — 195
— 17 39
— — 33
— — 185
— 17 37
— — 31
— — 150
— 11 30
— — 26
— — 145
— 11 29
— — 25
— — 220
— 12 44
— — 37
— — 195
— 12 39
— — 33
— — 75
— 5 15
— — 13
— 5 10
(C_L = 50 pF, Input t_r = t_f = 6 ns)
Ta = –40 to +85°C
Unit
Min
Max
Test Conditions
—
255 ns A, B or C to Y
—
51
—
43
—
255 ns A, B or C to W
—
51
—
43
—
245 ns Data to Y
—
49
—
42
—
230 ns Data to W
—
46
—
39
—
190 ns strobe to W R_L = 1 kΩ
—
38
—
33
—
180 ns strobe to Y R_L = 1 kΩ
—
36
—
31
—
275 ns strobe to W R_L = 1 kΩ
—
55
—
47
—
245 ns strobe to Y R_L = 1 kΩ
—
49
—
42
—
90
ns
—
19
—
16
—
10 pF
Test Circuit
VCC
Input
Pulse Generator
Zout = 50 Ω
VCC
Output
S
Y
D0 to D7
A
B
C
Output
W
1 k Ω _S1
C_L =
50 pF
1 k Ω _S1
C_L =
50 pF
Note : 1. C_L includes probe and jig capacitance.
OPEN
GND
V_CC
OPEN
GND
V_CC
TEST
t_PLH / t _PHL
t_ZH/ t _HZ
t_ZL / t _LZ
S1
OPEN
GND
V_CC
Rev.2.00 Jan 31, 2006 page 5 of 8