ST M74HCT157 User Manual

M74HCT157
QUAD 2 CHANNEL MULTIPLEXER
HIGH SPEED:
t
= 16ns (TYP.) at VCC = 4.5V
PD
LOW POWER DISSIPATION:
I
= 4µA(MAX.) at TA=25°C
CC
COMPA TIBLE WITH TTL OUTPUTS :
V
= 2V (MIN.) VIL = 0.8V (MAX)
IH
SYMMETRICAL OUTPUT IMPEDANCE:
|I
| = IOL = 4mA (MIN)
OH
BALANCED PROPAGATION DELAYS:
t
t
PHL
PLH
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 157
DESCRIPTION
The M74HCT157 is an high s peed CM OS QUA D 2 CHANNEL MULTIPLEXER fabricated with silicon gate C
2
MOS technology. This device consists of four 2-input digital multiplexer with common select and strobe inputs. When the STROBE
(ST) input is held high, selection of data is inhibited and all the outputs become low. The SELECT decodi ng determines
TSSOPDIP SOP
ORDER CODES
PACKAGE TUBE T & R
DIP M74HCT157B1R
SOP M74HCT157M1R M74HCT157RM13TR
TSSOP M74HCT157TTR
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
1/9September 2001
M74HCT157
INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION
PIN No SYMBOL NAME AND FUNCTION
1 SELECT Common Data Select
2, 5, 11, 14 1A to 4A Data Inputs From
3, 6, 10, 13 1B to 4B Data Inputs From
4, 7, 9, 12 1Y to 4Y Multiplexer Output
15 STROBE
8 GND Ground (0V)
16 V
TRUTH TABLE
INPUTS OUTPUTS
CC
Input
Source A
Source B
Strobe Inputs
Positive Supply Voltage
STROBE
HXXXL
LLLXL LLHXH LHXLL LHXHH
X : Don’t Care
LOGIC DIAGRAM
SELECT A B Y
2/9
M74HCT157
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
V
V
I
I
OK
I
I
or I
CC
P
T
T
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
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter Value Unit
V
V
V T t
r
Supply Voltage
CC
DC Input Voltage -0.5 to VCC + 0.5
I
DC Output Voltage -0.5 to VCC + 0.5
O
DC Input Diode Current
IK
DC Output Diode Current DC Output Current
O
DC VCC or Ground Current
GND
Power Dissipation
D
Storage Temperature
stg
Lead Temperature (10 sec)
L
°C; derate to 300mW by 10mW/°C from 65° C to 85°C
Supply Voltage
CC
Input Voltage 0 to V
I
Output Voltage 0 to V
O
Operating Temperature
op
, t
Input Rise and Fall Time (VCC = 4.5 to 5.5V)
f
-0.5 to +7 V
± 20 mA ± 20 mA ± 25 mA ± 50 mA
500(*) mW
-65 to +150 °C
300 °C
4.5 to 5.5 V
CC CC
-55 to 125 °C 0 to 500 ns
V V
V V
3/9
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