ST M74HC157 User Manual
M74HC157
QUAD 2 CHANNEL MULTIPLEXER
■HIGH SPEED:
tPD = 10ns (TYP.) at VCC = 6V
■LOW POWER DISSIPATION: ICC = 4μA(MAX.) at TA=25°C
■HIGH NOISE IMMUNITY: VNIH = VNIL = 28 % VCC (MIN.)
■SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 4mA (MIN)
■BALANCED PROPAGATION DELAYS: tPLH tPHL
■WIDE OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 6V
■PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 157
DIP |
SOP |
TSSOP |
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ORDER CODES |
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PACKAGE |
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TUBE |
T & R |
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DIP |
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M74HC157B1R |
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SOP |
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M74HC157M1R |
M74HC157RM13TR |
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TSSOP |
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M74HC157TTR |
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DESCRIPTION
The M74HC157 is an high speed CMOS QUAD 2 CHANNEL MULTIPLEXER fabricated with silicon gate C2MOS technology.
These device consist of four 2-input digital multiplexer with common select and strobe inputs. When the STROBE input is held high, selection of data is inhibited and all the outputs become low.
The SELECT decoding determines whether the A or B inputs get routed to their corresponding Y outputs.
All inputs are equipped with protection circuits against static discharge and transient excess voltage.
PIN CONNECTION AND IEC LOGIC SYMBOLS
July 2001 |
1/9 |
M74HC157
INPUT AND OUTPUT EQUIVALENT CIRCUIT |
PIN DESCRIPTION |
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PIN No |
SYMBOL |
NAME AND FUNCTION |
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1 |
SELECT |
Common Data Select |
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Input |
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2, 5, 11, 14 |
1A to 4A |
Data Inputs From |
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Source A |
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3, 6, 10, 13 |
1B to 4B |
Data Inputs From |
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Source B |
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4, 7, 9, 12 |
1Y to 4Y |
Multiplexer Output |
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15 |
STROBE |
Strobe Inputs |
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8 |
GND |
Ground (0V) |
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16 |
VCC |
Positive Supply Voltage |
TRUTH TABLE
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INPUTS |
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OUTPUTS |
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STROBE |
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SELECT |
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A |
B |
Y |
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H |
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X |
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X |
X |
L |
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L |
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L |
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L |
X |
L |
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L |
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L |
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H |
X |
H |
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L |
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H |
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X |
L |
L |
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L |
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H |
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X |
H |
H |
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X : Don’t Care
LOGIC DIAGRAM
2/9
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M74HC157 |
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ABSOLUTE MAXIMUM RATINGS |
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Symbol |
Parameter |
Value |
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Unit |
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VCC |
Supply Voltage |
-0.5 to +7 |
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V |
VI |
DC Input Voltage |
-0.5 to VCC + 0.5 |
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V |
VO |
DC Output Voltage |
-0.5 to VCC + 0.5 |
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V |
IIK |
DC Input Diode Current |
± 20 |
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mA |
IOK |
DC Output Diode Current |
± 20 |
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mA |
IO |
DC Output Current |
± 25 |
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mA |
ICC or IGND |
DC VCC or Ground Current |
± 50 |
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mA |
PD |
Power Dissipation |
500(*) |
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mW |
Tstg |
Storage Temperature |
-65 to +150 |
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°C |
TL |
Lead Temperature (10 sec) |
300 |
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°C |
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied
(*) 500mW at 65 °C; derate to 300mW by 10mW/°C from 65°C to 85°C
RECOMMENDED OPERATING CONDITIONS
Symbol |
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Parameter |
Value |
Unit |
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VCC |
Supply Voltage |
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2 to 6 |
V |
VI |
Input Voltage |
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0 to VCC |
V |
VO |
Output Voltage |
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0 to VCC |
V |
Top |
Operating Temperature |
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-55 to 125 |
°C |
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Input Rise and Fall Time |
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VCC = 2.0V |
0 to 1000 |
ns |
tr, tf |
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VCC = 4.5V |
0 to 500 |
ns |
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VCC = 6.0V |
0 to 400 |
ns |
3/9
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