SGS Thomson Microelectronics 74AC157 Datasheet
QUAD 2 CHANNEL MULTIPLEXER
■ HIGH SPEED:t
■ LOWPOWER DISSIPATION:
=8µA (MAX.)at TA=25oC
I
CC
■ HIGH NOISE IMMUNITY:
V
NIH=VNIL
■ 50Ω TRANSMISSION LINE DRIVING
CAPABILITY
■ SYMMETRICAL OUTPUT IMPEDANCE:
|I
|=IOL=24mA (MIN)
OH
■ BALANCE DPROPAGATIONDELAYS:
t
≅ t
PLH
PHL
■ OPERATINGVOLTAGERANGE:
V
(OPR) = 2V to 6V
CC
■ PIN AND FUNCTION COMPATIBLE WITH
74SERIES 157
■ IMPROVED LATCH-UP IMMUNITY
DESCRIPTION
The AC157 is an high-speed CMOS QUAD
2-CHANNEL MULTIPLEXER fabricated with
sub-micron silicon gate and double-layer metal
wiring C
2
MOS technology. It is ideal for low
power applications maintaining high speed
operation similar to equivalent Bipolar Schottky
TTL.
=4 ns(TYP.)atVCC=5V
PD
=28%VCC(MIN.)
74AC157
PRELIMINARY DATA
B
(Plastic Package)
(Micro Package)
ORDERCODES:
74AC157B 74AC157M
It consists of four 2-input digital multiplexers with
common select and strobe inputs. It is a
non-inverting multiplexer. When the STROBE
input is held high selection of data is inhibit and
all the outputs become low. The SELECT
decoding determines whether the A or B inputs
get routed to their correspondingY outputs.
All inputs and outputs are equipped with
protectioncircuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
M
PINCONNECTION ANDIEC LOGICSYMBOLS
May 1997
1/9
74AC157
INPUTAND OUTPUT EQUIVALENTCIRCUIT
PIN DESCRIPTION
PI N No SYM B O L NAME A ND FUNCTI ON
1 SELECT Common Data Select Input
2,5, 11, 14 1Ato4A Data Inputs From
Source A
3,6, 10, 13 1Bto4B Data Inputs From
Source B
4,7, 9,12 1Yto4Y Multiplexer Outputs
15 STROBE Strobe Input
8 GND Ground (0V)
16 V
CC
Positive Supply Voltage
TRUTH TABLE
INPUT OUTPUT
ST RO B E SE L ECT A B Y
HXXXL
LLLXL
LLHXH
LHXLL
LHXHH
X:”H”or”L”
LOGICDIAGRAM
2/9
74AC157
ABSOLUTE MAXIMUMRATING
Symb o l Parame t er Value Unit
V
V
V
I
I
OK
I
orI
I
CC
T
T
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
RECOMMENDED OPERATINGCONDITIONS
Symb o l Parame t er Val u e Uni t
V
V
V
T
dt/dv Input Rise and Fall Time V
1) VINfrom30% to70%of V
Supply Voltage -0.5to+7 V
CC
DC Input Voltage -0.5toVCC+0.5 V
I
DC Output Voltage -0.5toVCC+0.5 V
O
DC Input Diode Current ± 20 mA
IK
DC Output Diode Current ± 20 mA
DC Output Current ± 50 mA
O
DC VCCor Ground Current ± 200 mA
GND
Storage Temperature -65to+150
stg
Lead Temperature (10 sec) 300
L
Supply Voltage 2to6 V
CC
Input Voltage 0toV
I
Output Voltage 0toV
O
Operating Temperature: -40to+85
op
= 3.0, 4.5 or 5.5 V(note 1) 8 ns/V
CC
CC
CC
CC
o
C
o
C
V
V
o
C
3/9
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