Fairchild Semiconductor 74ACT157SJX, 74ACT157SJ, 74ACT157SCX, 74ACT157SC, 74ACT157PC Datasheet
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© 1999 Fairchild Semiconductor Corporation DS009929 www.fairchildsemi.com
November 1988
Revised November 1999
74AC157 • 74ACT157 Quad 2-Input Multiplexer
74AC157 • 74ACT157
Quad 2-Input Multiplexer
General Description
The AC/ACT157 is a high-speed quad 2-input multiplex er.
Four bits of data from two so urces can be selected using
the common Select and Enable inputs. The four outputs
present the selected data in the true (noninverted) form.
The AC/ACT157 can also be used as a function generator.
Features
■ ICC and IOZ reduced by 5 0%
■ Outputs source/sink 24 mA
■ ACT157 has TTL-compatible inputs
Ordering Code:
Device also available in Tape and Reel. Specify by appending s uffix let te r “X” to the ordering code.
Logic Symbols
IEEE/IEC
Connection Diagram
Pin Descriptions
FACT is a trademark of Fairchild Semiconductor Corporation.
Order Number Package Number Package Description
74AC157SC M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow Body
74AC157SJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74AC157MTC MTC16 16 -Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74AC157PC N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
74ACT157SC M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow Body
74ACT157SJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74ACT157MTC MTC16 16 -Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74ACT157PC N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
Pin Names Description
I
0a–I0d
Source 0 Data Inputs
I
1a–I1d
Source 1 Data Inputs
E
Enable Input
S Select Input
Z
a–Zd
Outputs
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74AC157 • 74ACT157
Functional Description
The AC/ACT157 is a quad 2-input multiplexer. It selects
four bits of data f rom two sources under the control of a
common Select input (S ). The Enable input (E
) is active-
LOW. When E
is HIGH, all of the o utputs (Z) are forced
LOW regardless of a ll other in puts. T he AC/A CT15 7 i s the
logic implementation of a 4-po le, 2-position switch where
the position of the swit ch is determined b y the logic level s
supplied to the Se lect input. The logic equations for the
outputs are shown below:
Z
a
= E • (I
1a
• S + I0a • S)
Z
b
= E • (I
1b
• S + I0b • S)
Z
c
= E • (I1c • S + I0c • S)
Z
d
= E • (I1d • S + I0d • S)
A common use of the AC/AC T157 is the moving of data
from two groups of register s to four common output busses. The particula r register from which the data co mes is
determined by the state o f the S elect i nput. A less o bvious
use is as a function generator. The AC/ACT15 7 can ge ner ate any four of th e sixteen different function s of two variables with one variable common. This is useful for
implementing gating functions.
Tr uth Table
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
Logic Diagram
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
Inputs Outputs
E
SI0I
1
Z
HX X X L
LH X L L
LH X H H
LL L X L
LLH X H
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74AC157 • 74ACT157
Absolute Maximum Ratings(Note 1) Recommended Operating
Conditions
Note 1: Absolute max imum ratings are those values beyond w hich damage
to the device may occu r. The databook spe cificatio ns shou ld be met, wit hout exception, to ensure that the system de sign is relia ble over its p ower
supply, temperature, and output/input loading variables. Fairchild does not
recommend operation of FACT circuits outside databook specif ic at ions.
DC Electrical Characteristics for AC
Note 2: All outputs loaded; thres holds on input associate d w it h output under test.
Note 3: Maximum test duration 2.0 ms, one output loaded at a time.
Note 4: I
IN
and ICC @ 3.0V are guaranteed to be less than or equa l t o th e respective limit @ 5.5V VCC.
Supply Voltage (VCC) −0.5V to +7.0V
DC Input Diode Current (I
IK
)
V
I
= −0.5V −20 mA
V
I
= VCC + 0.5V +20 mA
DC Input Voltage (V
I
) −0.5V to VCC + 0.5V
DC Output Diode Current (I
OK
)
V
O
= −0.5V −20 mA
V
O
= VCC + 0.5V +20 mA
DC Output Voltage (V
O
) −0.5V to VCC + 0.5V
DC Output Source
or Sink Current (I
O
) ±50 mA
DC V
CC
or Ground Current
per Output Pin (I
CC
or I
GND
) ±50 mA
Storage Temperature (T
STG
) −65°C to +150°C
Junction Temperature (T
J
)
PDIP 140°C
Supply Voltage (V
CC
)
AC 2.0V to 6.0V
ACT 4.5V to 5.5V
Input Voltage (V
I
) 0V to V
CC
Output Voltage (VO) 0V to V
CC
Operating Temperature (TA) −40°C to +85°C
Minimum Input Edge Rate (∆V/∆t)
AC Devices
V
IN
from 30% to 70% of V
CC
VCC @ 3.3V, 4.5V, 5.5V 125 mV/ns
Minimum Input Edge Rate (∆V/∆t)
ACT Devices
V
IN
from 0.8V to 2.0V
V
CC
@ 4.5V, 5.5V 125 mV/ns
Symbol Parameter
V
CC
TA = +25°C TA = −40°C to +85°C
Units Conditions
(V) Typ Guaranteed Limits
V
IH
Minimum HIGH Level 3.0 1.5 2.1 2.1 V
OUT
= 0.1V
Input Voltage 4.5 2.25 3.15 3.15 V or VCC − 0.1V
5.5 2.75 3.85 3.85
V
IL
Maximum LOW Level 3.0 1.5 0.9 0.9 V
OUT
= 0.1V
Input Voltage 4.5 2.25 1.35 1.35 V or VCC − 0.1V
5.5 2.75 1.65 1.65
V
OH
Minimum HIGH Level 3.0 2.99 2.9 2.9
Output Voltage 4.5 4.49 4.4 4.4 V I
OUT
= −50 µA
5.5 5.49 5.4 5.4
VIN = V
IL
or V
IH
3.0 2.56 2.46 IOH = −12 mA
4.5 3.86 3.76 V I
OH
= −24 mA
5.5 4.86 4.76 I
OH
= −24 mA (Note 2)
V
OL
Maximum LOW Level 3.0 0.002 0.1 0.1
Output Voltage 4.5 0.001 0.1 0.1 V I
OUT
= 50 µA
5.5 0.001 0.1 0.1
VIN = V
IL
or V
IH
3.0 0.36 0.44 IOL = 12 mA
4.5 0.36 0.44 V IOL = 24 mA
5.5 0.36 0.44 IOL = 24 mA (Note 2)
I
IN
Maximum Input
5.5 ±0.1 ±1.0 µA VI = VCC, GND
(Note 4) Leakage Current
I
OLD
Minimum Dynamic 5.5 75 mA V
OLD
= 1.65V Max
I
OHD
Output Current (Note 3) 5.5 −75 mA V
OHD
= 3.85V Min
ICC Maximum Quiescent
5.5 4.0 40.0 µA
VIN = V
CC
(Note 4) Supply Current or GND
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