74ALS253 데이터 시트보기 (PDF) - Philips Electronics
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74ALS253 Datasheet PDF : 9 Pages
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Philips Semiconductors
Dual 4-input multiplexer (3-State)
Product specification
74ALS253
FEATURES
• 3-State outputs for bus interface and multiplex operation
• Common select inputs
• Separate output enable inputs
DESCRIPTION
The 74ALS253 has two identical 4-input multiplexers with 3-State
outputs which select 2 bits from four sources by using common
select input (S0, S1). When the individual output enable (OEa,
OEb) inputs of the 4-input multiplexers are High, the outputs are
forced to a High impedance (Z) state.
The 74ALS253 is the logic implementation of 2-pole, 4-position
switch being determined by the logic levels supplied to the common
select inputs.
To avoid exceeding the maximum current ratings when the outputs
of the 3-State devices are tied together, all but one device must be
in the High impedance state. Therefore, only one output enable
must be achieved at a time.
TYPE
TYPICAL
PROPAGATION DELAY
74ALS253
7.0ns
TYPICAL
SUPPLY CURRENT
(TOTAL)
8mA
PIN CONFIGURATION
OEa 1
S1 2
I3a 3
I2a 4
I1a 5
I0a 6
Ya 7
GND 8
16 VCC
15 OEb
14 S0
13 I3b
12 I2b
11 I1b
10 I0b
9 Yb
SF00798
ORDERING INFORMATION
ORDER CODE
DESCRIPTION
COMMERCIAL RANGE
VCC = 5V ±10%,
Tamb = 0°C to +70°C
16-pin plastic DIP
74ALS253N
16-pin plastic SO
74ALS253D
16-pin plastic SSOP
Type II
74ALS253DB
DRAWING
NUMBER
SOT38-4
SOT109-1
SOT338-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
DESCRIPTION
74ALS (U.L.)
HIGH/LOW
I0a – I3a
Port A data inputs
1.0/1.0
I0b – I3b
Port B data inputs
1.0/1.0
S0, S1
Common select inputs
1.0/1.0
OEa
Port A Output Enable input (active-Low)
1.0/1.0
OEb
Port B Output Enable input (active-Low)
1.0/1.0
Ya – Yb
3-State outputs
130/240
NOTE: One (1.0) ALS unit load is defined as: 20µA in the High state and 0.1mA in the Low state.
LOGIC SYMBOL
IEC/IEEE SYMBOL
LOAD VALUE
HIGH/LOW
20µA/0.1mA
20µA/0.1mA
20µA/0.1mA
20µA/0.1mA
20µA/0.1mA
2.6mA/24mA
6 5 4 3 10 11 12 13
14
2
0
2
G
0
3
I0a I1a I2a I3a I0b I1b I2b I3b
14
S0
2
S1
1
OEa
15
OEb
Ya Yb
VCC = Pin 16
GND = Pin 8
79
SF00799
1
MUX
EN
6
0
5
1
4
2
3
3
15
10
11
12
13
7
9
SC00073
1991 Feb 08
2
853–1378 01670
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