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Details, datasheet, quote on part number:N74F257AD
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Datasheet text preview:
INTEGRATED CIRCUITS
74F257A Quad 2-line to 1-line selector/multiplexer, non-inverting (3-State)
Product specification IC15 Data Handbook 1995 Mar 31
Philips Semiconductors
Philips Semiconductors
Product specification
Quad 2-line to 1-line selector/multiplexer, non-inverting (3-State)
74F257A
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.
PIN CONFIGURATION
S I0a I1a Ya I0b I1b Yb GND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VCC OE I0d I1d Yd I0c I1c Yc
SF00673
TYPE 74F257A
TYPICAL PROPAGATION DELAY 4.3ns
TYPICAL SUPPLY CURRENT (TOTAL) 12mA
ORDERING INFORMATION
ORDER CODE DESCRIPTION 16-pin plastic DIP 16-pin plastic SO COMMERCIAL RANGE VCC = 5V ±10%, Tamb = 0°C to +70°C N74F257AN N74F257AD INDUSTRIAL RANGE VCC = 5V ±10%, Tamb = 40°C to +85°C I74F257AN I74F257AD DRAWING NUMBER SOT38-4 SOT109-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS I0n, I1n S OE Ya Yd DESCRIPTION Data inputs Common Select input Output Enable input (active Low) Data outputs 74F (U.L.) HIGH/LOW 1.0/1.0 1.0/1.0 1.0/1.0 150/33 LOAD VALUE HIGH/LOW 20µA/0.6mA 20µA/0.6mA 20µA/0.6mA 3.0mA/20mA
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 6 11 10 14 13
LOGIC SYMBOL (IEEE/IEC)
15 1 EN G1
2 I0a I1a I0b 1 15 S OE Ya Yb Yc Yd I1b I0c I1c I0d I1d 3 5 6 10
1 1
MUX 4
7
9 11 13 12
VCC = Pin 16 GND = Pin 8
4
7
9
12
14
SF00674
SF00675
1995 Mar 31
2
8530360 15059
Philips Semiconductors
Product specification
Quad 2-line to 1-line selector/multiplexer, non-inverting (3-State)
74F257A
LOGIC DIAGRAM
OE 15 I0a 2 I1a 3 I0b 5 I1b 6 I0c 11 I1c 10 I0d 14 I1d 13 S 1
FUNCTION TABLE
INPUTS OE H L L L L H L X Z = = = = S X H H L L I0 X X X L H I1 X L H X X OUTPUT Y Z L H L H
High voltage level Low voltage level Don't care High impedance "off" state
4 Ya VCC = Pin 16 GND = Pin 8 Yb
7 Yc
9
12 Yd
SF00676
APPLICATION
ENABLE S2
C B A Y0 Y1 Y2 Y3 74F139
S1
S0 WORD A WORD B WORD C WORD D WORD E WORD F WORD G WORD H
I0a I1a I0b I1b I0c I1c I0d I1d OE S Ya Yb Yc Yd 74F257A
I0a I1a I0b I1b I0c I1c I0d I1d OE S Ya Yb Yc Yd 74F257A
I0a I1a I0b I1b I0c I1c I0d I1d OE S Ya Yb Yc Yd 74F257A
I0a I1a I0b I1b I0c I1c I0d I1d OE S Ya Yb Yc Yd 74F257A
4-BIT DATA BUS
SF00677
1995 Mar 31
3
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