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HD74HC257 Datasheet, PDF (4/8 Pages) Hitachi Semiconductor – Quad. 2-to-1-line Data Selectors/Multiplexers(with noninverted 3-state outputs)
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HD74HC257
Switching Characteristics
Item
Symbol VCC (V)
Propagation delay tPHL
2.0
time
4.5
6.0
tPLH
2.0
4.5
6.0
tPHL
2.0
4.5
6.0
tPLH
2.0
4.5
6.0
Output enable time tZL
2.0
4.5
6.0
tZH
2.0
4.5
6.0
Output disable
time
tLZ
2.0
4.5
6.0
tHZ
2.0
4.5
6.0
Output rise/fall
time
tTLH
2.0
tTHL
4.5
6.0
Input capacitance Cin
—
Ta = 25°C
Min Typ Max
— — 115
— 11 23
— — 20
— — 115
— 10 23
— — 20
— — 115
— 14 23
— — 20
— — 115
— 14 23
— — 20
— — 150
— 11 30
— — 26
— — 150
— 13 30
— — 26
— — 150
— 14 30
— — 26
— — 150
— 18 30
— — 26
— — 60
— 4 12
— — 10
— 5 10
(CL = 50 pF, Input tr = tf = 6 ns)
Ta = –40 to +85°C
Unit
Min
Max
Test Conditions
—
145 ns Data to Y
—
29
—
25
—
145 ns
—
29
—
25
—
145 ns Select to Y
—
29
—
25
—
145 ns
—
29
—
25
—
190 ns Output control to Y
—
38
—
33
—
190 ns
—
38
—
33
—
190 ns Output control to Y
—
38
—
33
—
190 ns
—
38
—
33
—
75
ns
—
15
—
13
—
10 pF
Test Circuit
VCC
VCC
Output
Input
Pulse Generator
Zout = 50 Ω
OC
1Y
1A to 4A
Output
2Y
Output
1B to 4B
3Y
Output
1 k Ω S1
CL = 50 pF
OPEN
GND
VCC
Same as Load Circuit
Same as Load Circuit
S
4Y
Same as Load Circuit
Note : 1. CL includes probe and jig capacitance.
TEST
tPLH / t PHL
tZH/ t HZ
tZL / t LZ
S1
OPEN
GND
VCC
Rev.2.00 Jan 31, 2006 page 4 of 7
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