MC74HCT157A Datasheet, PDF (1/5 Pages) Motorola, Inc – Quad 2-Input Data Selector/Multiplexer with LSTTL-Compatible Inputs

MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Quad 2-Input Data
Selector/Multiplexer with
LSTTL-Compatible Inputs
High–Performance Silicon–Gate CMOS
The MC74HCT157A is identical in pinout to the LS157. This device may
be used as a level converter for interfacing TTL or NMOS outputs to High
Speed CMOS inputs.
This device routes 2 nibbles (A or B) to a single port (Y) as determined by
the Select input. The data is presented at the outputs in noninverted form. A
high level on the Output Enable input sets all four Y outputs to a low level.
The HCT157A is similar in function to the HC257 which has 3–state
outputs.
• Output Drive Capability: 10 LSTTL Loads
• TTL NMOS Compatible Input Levels
• Outputs Directly Interface to CMOS, NMOS and TTL
• Operating Voltage Range: 4.5 to 5.5 V
• Low Input Current: 1.0 µA
• In Compliance with the Requirements Defined by JEDEC Standard
No. 7A
• Chip Complexity: 102 FETs or 25.5 Equivalent Gates
LOGIC DIAGRAM
NIBBLE
A INPUTS
NIBBLE
B INPUTS
2
A0
A1 ⁵
11
A2
A3 ¹⁴
3
B0
6
B1
10
B2
13
B3
4
Y0
7
Y1
9
Y2
12
Y3
DATA
OUTPUTS
PIN 16 = VCC
PIN 8 = GND
1
SELECT
OUTPUT ENABLE ¹⁵
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ _{Design Criteria}
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ _{Internal Gate Count*}
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ _{Internal Gate Propagation Delay}
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ _{Internal Gate Power Dissipation}
ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ _{Speed Power Product}
Value
Unit
25.5
ea
1.5
ns
0.005
µW
0.0075
pJ
* Equivalent to a two input NAND gate.
MC74HCT157A
16
1
N SUFFIX
PLASTIC PACKAGE
CASE 648–08
16
1
D SUFFIX
SOIC PACKAGE
CASE 751B–05
ORDERING INFORMATION
MC74HCTXXXAN Plastic
MC74HCTXXXAD SOIC
PIN ASSIGNMENT
SELECT 1
A0 2
B0 3
Y0 4
A1 5
B1 6
Y1 7
GND 8
16 VCC
15 ^OUTPUT
ENABLE
14 A3
13 B3
12 Y3
11 A2
10 B2
9 Y2
FUNCTION TABLE
Inputs
Output
Outputs
Enable Select Y0 – Y3
H
X
L
L
L A0 – A3
L
H B0 – B3
X = don’t care
A0 – A3, B0 – B3 = the levels
of the respective Data–Word
Inputs.
2/97
© Motorola, Inc. 1997
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