Table of Contents
Advertisement
Philips Semiconductors
Quad 2-line to 1-line selector/multiplexer, non-inverting
(3-State)
FEATURES
Industrial range available (–40 C to +85 C)
Multifunction capability
Non-inverting data path
3-State outputs
See 74F258A for inverting version
DESCRIPTION
The 74F257A has four identical 2-input multiplexers with 3-State
outputs which select 4 bits of data from two sources uncer control of
a common Select (S) input. The I0a inputs are selected when the
common Select input is Low and the I1n inputs are selected when
the common Select input is High. Data appears at the outputs in true
non-inverted form from the selected inputs. The 74F257A is the logic
implementation of a 4-pole, 2-position switch where the position of
the switch is determined by the logic levels supplied to the common
Slect input. Outputs are forced to a high impedance "off" state when
the Output Enable (OE) is High. All but one device must be in high
impedance state to avoid currents that would exceed the maximum
rating if the outputs were tied together. Design of the Output Enable
signals must ensure that there is no overlap when outputs of 3-state
devices were tied together.
ORDERING INFORMATION
DESCRIPTION
V
CC
16-pin plastic DIP
16-pin plastic SO
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
DESCRIPTION
I0n, I1n
Data inputs
S
Common Select input
OE
Output Enable input (active Low)
Ya – Yd
Data outputs
NOTE:
One (1.0) FAST unit load is defined as: 20µA in the High state and 0.6mA in the Low state.
LOGIC SYMBOL
2
3
5
I0a I1a I0b I1b I0c I1c I0d
1
S
15
OE
Ya
4
V
= Pin 16
CC
GND = Pin 8
1995 Mar 31
ORDER CODE
COMMERCIAL RANGE
= 5V 10%, T
= 0 C to +70 C
amb
N74F257AN
N74F257AD
6
11
10
14
13
I1d
Yb
Yc
Yd
7
9
12
SF00674
PIN CONFIGURATION
S
1
I0a
2
I1a
3
Ya
4
I0b
5
I1b
6
Yb
7
GND
8
TYPICAL
TYPE
PROPAGATION DELAY
74F257A
4.3ns
INDUSTRIAL RANGE
V
= 5V 10%, T
= –40 C to +85 C
CC
amb
I74F257AN
I74F257AD
74F (U.L.) HIGH/LOW
1.0/1.0
1.0/1.0
1.0/1.0
150/33
LOGIC SYMBOL (IEEE/IEC)
15
EN
1
G1
2
1
3
1
5
6
10
11
13
14
2
Product specification
74F257A
16
V
CC
15
OE
14
I0d
13
I1d
12
Yd
11
I0c
10
I1c
9
Yc
SF00673
TYPICAL
SUPPLY CURRENT
(TOTAL)
12mA
DRAWING
DRAWING
NUMBER
SOT38-4
SOT109-1
LOAD VALUE HIGH/LOW
20µA/0.6mA
20µA/0.6mA
20µA/0.6mA
3.0mA/20mA
MUX
4
7
9
12
SF00675
853–0360 15059
Advertisement
Table of Contents
