Document
SN74LS42
One−of−Ten Decoder
The LSTTL / MSI SN74LS42 is a Multipurpose Decoder designed to accept four BCD inputs and provide ten mutually exclusive outputs. The LS42 is fabricated with the Schottky barrier diode process for high speed and is completely compatible with all ON Semiconductor TTL families.
• Multifunction Capability • Mutually Exclusive Outputs • Demultiplexing Capability • Input Clamp Diodes Limit High Speed Termination Effects
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LOW POWER SCHOTTKY
GUARANTEED OPERATING RANGES
Symbol
Parameter
Min Typ Max Unit
VCC
Supply Voltage
TA
Operating Ambient
Temperature Range
4.75 5.0 5.25
V
0
25
70
°C
IOH
Output Current − High
IOL
Output Current − Low
−0.4 mA
8.0
mA
16 1 PLASTIC N SUFFIX CASE 648
16 1
SOIC D SUFFIX CASE 751B
© Semiconductor Components Industries, LLC, 2006
July, 2006 − Rev. 8
16 1
SOEIAJ M SUFFIX CASE 966
ORDERING INFORMATION
Device
Package
Shipping
SN74LS42N
16 Pin DIP 2000 Units/Box
SN74LS42D
SOIC−16
38 Units/Rail
SN74LS42DR2
SOIC−16 2500/Tape & Reel
SN74LS42M
SOEIAJ−16 See Note 1
SN74LS42MEL SOEIAJ−16 See Note 1
1. For ordering information on the EIAJ version of the SOIC package, please contact your local ON Semiconductor representative.
1
Publication Order Number:
SN74LS42/D
SN74LS42
CONNECTION DIAGRAM DIP (TOP VIEW)
VCC A0 A1 A2 A3 9 16 15 14 13 12 11
1 2 3 4 56 0 1 2 3 45
87 10 9
78 6 GND
NOTE: The Flatpak version has the same pinouts (Connection Diagram) as the Dual In-Line Package.
PIN NAMES
A0 − A3 0 to 9
Address Inputs Outputs, Active LOW
LOADING (Note a)
HIGH
LOW
0.5 U.L. 10 U.L.
0.25 U.L. 5 U.L.
NOTES: a) 1 TTL Unit Load (U.L.) = 40 mA HIGH/1.6 mA LOW.
LOGIC SYMBOL 15 14 13 12
A0 A1 A2 A3
012345 6 7 89
1 2 3 4 5 6 7 9 10 11 VCC = PIN 16 GND = PIN 8
A0
15
LOGIC DIAGRAM
A1
14
A2
13
A3
12
1
2
3
4
5
6
7
9
10
11
0
1
2
3
4
5
6
7
8
9
VCC = PIN 16 GND = PIN 8
= PIN NUMBERS
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SN74LS42
FUNCTIONAL DESCRIPTION
The LS42 decoder accepts four active HIGH BCD inputs and provides ten mutually exclusive active LOW outputs, as shown by logic symbol or diagram. The active LOW outputs facilitate addressing other MSI units with LOW input enables.
The logic design of the LS42 ensures that all outputs are HIGH when binary codes greater than nine are applied to the inputs.
The most significant input A3 produces a useful inhibit function when the LS42 is used as a one-of-eight decoder.
The A3 input can also be used as the Data input in an 8-output demultiplexer application.
TRUTH TABLE
A0 A1 A2 A3 0 1 2 3 4 5 6 7 8 9
L L L L LHHHHHHHHH H L L L HLHHHHHHHH L H L L HHLHHHHHHH H H L L HHHLHHHHHH L L H L HHHHLHHHHH H L H L HHHHHLHHHH L H H L HHHHHHLHHH H H H L HHHHHHHLHH L L L H HHHHHHHHLH H L L H HHHHHHHHHL L H L H HHHHHHHHHH H H L H HHHHHHHHHH L L H H HHHHHHHHHH H L H H HHHHHHHHHH L H H H HHHHHHHHHH H H H H HHHHHHHHHH
H = HIGH Voltage Level L = LOW Voltage Level
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SN74LS42
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Limits
Symbol
Parameter
VIH
Input HIGH Voltage
Min
Typ
Max
Unit
Test Conditions
2.0
V
Guaranteed Input HIGH Voltage for All Inputs
VIL
Input LOW Voltage
0.8
V
Guaranteed Input LOW Voltage for All Inputs
VIK
Input Clamp Diode Voltage
− 0.65
− 1.5
V
VCC = MIN, IIN = − 18 mA
VOH
Output HIGH Voltage
2.7
3.5
V
VCC = MIN, IOH = MAX, VIN = VIH
or VIL per Truth Table
VOL
Output LOW Voltage
0.25
0.4
0.35
0.5
V
IOL = 4.0 mA
VCC = VCC MIN,
VIN = VIL or VIH
V
IOL = 8.0 mA per Truth Table
IIH
Input HIGH Current
20
μA
VCC = MAX, VIN = 2.7 V
0.1
mA
VCC = MAX, VIN = 7.0 V
IIL
Input LOW Current
− 0.4
mA
VCC = MAX, VIN = 0.4 V
IOS
Short Circuit Current (Note 2)
− 20
−100
mA
VCC = MAX
ICC
Power Supply Current
13
mA
VCC = MAX
2. Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS (TA = 25°C)
Symbol
tPLH tPHL
tPLH tPHL
Parameter
Propagation Delay (2 Levels)
Propagation Delay (3 Levels)
Limits
Min
Typ
Max
15
25
15
25
20
30
20
30
Unit ns
ns
Test Conditions
Figure 2
Figure 1
VCC = 5.0 V CL = 15 pF
AC WAVEFORMS
VIN VOUT
1.3 V tPHL
1.3 V
1.3 V tPLH
1.3 V
Figure 1.
VIN VOUT
1.3 V tPHL 1.3 V
1.3 V tPLH
1.3 V
Figure 2.
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SN74LS42
PACKAGE DIMENSIONS
−A−
16 1
H G
N SUFFIX PLASTIC PACKAGE
CASE 648−08 ISSUE R
9
B
8
F
C
L
S
−T−
SEATING PLANE
K
J
M
D 16 PL 0.25 (0.010) M T A M
NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH. 5. ROUNDED CORNERS OPTIONAL.
INCHES
MILLIMETERS
DIM MIN MAX MIN MAX
A 0.740 0.770 18.80 19.55
B 0.250 0.270 6.35 6.85
C 0.145 0.175 3.69 4.44
D 0.015 0.021 0.39 0.53
F 0.040 0.70 1.02 1.77
G 0.100 BSC
2.54 BSC
H 0.050 BSC
1.27 BSC
J 0..