74ALS138
1-of-8 decoder/demultiplexer
Product specification 1996 Jul 03
INTEGRATED CIRCUITS
IC05 Data Handbook
Philips Semiconductors Product specification
74ALS1381-of-8 decoder/demultiplexer
2
1996 Jul 03 853–1848 17016
FEATURES
•Demultiplexing capability
•Multiple input enable for easy expansion
•Ideal for memory chip select decoding
DESCRIPTION
The 74ALS138 decoder accepts three binary weighted inputs (A0,
A1, A2) and when enabled, provides eight mutually exclusive,
active-Low outputs (Q0 – Q7). The device features three Enable
inputs; two active-Low (E0, E1) and one active-High (E2). Every
output will be High unless E0 and E1 are Low and E2 is High. This
multiple enable function allows easy parallel expansion of the device
to 1-of-32 (5 lines to 32 lines) decoder with just four 74ALS138s and
one inverter. The device can be used as an eight output
demultiplexer by using one of the active-Low Enable inputs as the
data input and the remaining Enable inputs as strobes. Enable
inputs not used must be permanently tied to their appropriate
active-High or active-Low state.
TYPE TYPICAL
PROPAGATION DELAY
TYPICAL
SUPPLY CURRENT
(TOTAL)
74ALS138 12.0ns 4.0mA
PIN CONFIGURATION
16
15
14
13
12
11
107
6
5
4
3
2
1
Q7
VCC
Q3
Q4
Q5
Q2
Q0
Q1
A0
A1
E2
A2
E0
E1
98GND Q6
SF00174
ORDERING INFORMATION
ORDER CODE
DESCRIPTION COMMERCIAL RANGE
VCC = 5V ±10%,
Tamb = 0°C to +70°C
DRAWING
NUMBER
16-pin plastic DIP 74ALS138N SOT38-4
16-pin plastic SO 74ALS138D SOT109-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS DESCRIPTION 74ALS (U.L.)
HIGH/LOW LOAD VALUE
HIGH/LOW
A0 – A2 Address inputs 1.0/1.0 20µA/0.1mA
E0, E1 Enable inputs (active-Low) 1.0/1.0 20µA/0.1mA
E2 Enable input (active-High) 1.0/1.0 20µA/0.1mA
Q0 – Q7 Data outputs (active-Low) 50/33 1.0mA/20mA
NOTE: One (1.0) ALS unit load is defined as: 20µA in the High state and 0.1mA in the Low state.
LOGIC SYMBOL
A1 A2A0
Q2 Q3 Q4 Q5
13 12 11 10
123
V
CC = Pin 16
GND = Pin 8
SF00175
Q1
14
Q0
15
Q6
9
Q7
7
4
5
6
E0
E1
E2
IEC/IEEE SYMBOL
SC00047
DX
1
2
4
5
6
15
14
13
12
11
10
9
7
00
1
2
G0
7
3
32
&
Philips Semiconductors Product specification
74ALS1381-of-8 decoder/demultiplexer
1996 Jul 03 3
LOGIC DIAGRAM
15 14 13 12 11 10 9 7
Q0Q1Q2Q3Q4Q5Q6Q7
3
2
1
4
5
6
A2
A1
A0
E0
E1
E2
VCC = Pin 16
GND = Pin 8
SF00177
FUNCTION TABLE
INPUTS OUTPUTS
E0 E1 E2 A0 A1 A2 Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
H X X X X X H H H H H H H H
X H X X X X H H H H H H H H
X X L X X X H H H H H H H H
L L H L L L L H H H H H H H
L L H H L L H L H H H H H H
L L H L H L H H L H H H H H
L L H H H L H H H L H H H H
L L H L L H H H H H L H H H
L L H H L H H H H H H L H H
L L H L H H H H H H H H L H
L L H H H H H H H H H H H L
H = High voltage level
L = Low voltage level
X = Don’t care
Philips Semiconductors Product specification
74ALS1381-of-8 decoder/demultiplexer
1996 Jul 03 4
ABSOLUTE MAXIMUM RATINGS
(Operation beyond the limit set forth in this table may impair the useful life of the device.
Unless otherwise noted these limits are over the operating free-air temperature range.)
SYMBOL PARAMETER RATING UNIT
VCC Supply voltage –0.5 to +7.0 V
VIN Input voltage –0.5 to +7.0 V
IIN Input current –30 to +5 mA
VOUT Voltage applied to output in High output state –0.5 to VCC V
IOUT Current applied to output in Low output state 16 mA
Tamb Operating free-air temperature range 0 to +70 °C
Tstg Storage temperature range –65 to +150 °C
RECOMMENDED OPERATING CONDITIONS
SYMBOL
PARAMETER
LIMITS
UNIT
SYMBOL
PARAMETER
MIN NOM MAX
UNIT
VCC Supply voltage 4.5 5.0 5.5 V
VIH High-level input voltage 2.0 V
VIL Low-level input voltage 0.8 V
IIk Input clamp current –18 mA
IOH High-level output current –0.4 mA
IOL Low-level output current 8 mA
Tamb Operating free-air temperature range 0 +70 °C
DC ELECTRICAL CHARACTERISTICS
(Over recommended operating free-air temperature range unless otherwise noted.)
SYMBOL
PARAMETER
TEST CONDITIONS1
LIMITS
UNIT
SYMBOL
PARAMETER
TEST
CONDITIONS1
MIN TYP2MAX
UNIT
VOH High-level output voltage VCC = ±10%, VIL = MAX,
VIH = MIN IOH = –0.4mA VCC – 2 V
VO
Low level out
p
ut voltage
V
CC
= MIN, VIL = MAX, IOL = 4mA 0.25 0.40 V
V
OL
Lo
w-
le
v
el
o
u
tp
u
t
v
oltage
CC ,IL ,
VIH = MIN IOL = 8mA 0.35 0.50 V
VIK Input clamp voltage VCC = MIN, II = IIK –0.73 –1.5 V
IIInput current at maximum input
voltage VCC = MAX, VI = 7.0V 0.1 mA
IIH High-level input current VCC = MAX, VI = 2.7V 20 µA
IIL Low-level input current VCC = MAX, VI = 0.4V –0.1 mA
IOOutput current3VCC = MAX, VO = 2.25V –30 –112 mA
ICC Supply current (total) VCC = MAX 4 7 mA
NOTES:
1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable type.
2. All typical values are at VCC = 5V, Tamb = 25°C.
3. The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
Philips Semiconductors Product specification
74ALS1381-of-8 decoder/demultiplexer
1996 Jul 03 5
AC ELECTRICAL CHARACTERISTICS
LIMITS
SYMBOL PARAMETER TEST CONDITION Tamb = 0°C to +70°C
VCC = +5.0V ± 10%
CL = 50pF, RL = 500ΩUNIT
MIN MAX
tPLH
tPHL Propagation delay
An to Qn W aveform 1, 2 3.0
3.0 22.0
18.0 ns
tPLH
tPHL Propagation delay
E1, E2 to Qn W aveform 2 3.0
3.0 17.0
17.0 ns
tPLH
tPHL Propagation delay
E2 to Qn W aveform 1 3.0
3.0 17.0
17.0 ns
AC WAVEFORMS
For all waveforms, VM = 1.3V.
VM
VM
VM
VM
Qn
An, E2
tPHL tPLH
SF00179
W aveform 1. Propagation Delay for Inverting Outputs
VM
VM
VM
VM
Qn
An, E0, E1
tPHL tPLH
SF00180
W aveform 2. Propagation Delay for Non-inverting Outputs
TEST CIRCUIT AND WAVEFORMS
tw90%
VM
10%
90%
VM10%
90%
VM10%
90%
VM
10%
NEGATIVE
PULSE
POSITIVE
PULSE
tw
AMP (V)
0.3V
0.3V
tTHL (tff)
INPUT PULSE REQUIREMENTS
Rep.Rate twtTLH tTHL
1MHz 500ns 2.0ns 2.0ns
Input Pulse Definition
VCC
Family
74ALS
D.U.T.
PULSE
GENERATOR
RL
CL
RT
VIN VOUT
Test Circuit for Totem-pole Outputs
DEFINITIONS:
RL= Load resistor;
see AC electrical characteristics for value.
CL= Load capacitance includes jig and probe capacitance;
see AC electrical characteristics for value.
RT= Termination resistance should be equal to ZOUT of
pulse generators.
tTHL (tf )
tTLH (tr )
tTLH (tr )AMP (V)
Amplitude
3.5V 1.3V
VM
SC00005
Philips Semiconductors Product specification
74ALS1381-of-8 decoder/demultiplexer
1996 Jul 03 6
DIP16: plastic dual in-line package; 16 leads (300 mil) SOT38-4
Philips Semiconductors Product specification
74ALS1381-of-8 decoder/demultiplexer
1996 Jul 03 7
SO16: plastic small outline package; 16 leads; body width 3.9 mm SOT109-1
Philips Semiconductors Product specification
74ALS1381-of-8 decoder/demultiplexer
1996 Jul 03 8
Philips Semiconductors and Philips Electronics North America Corporation reserve the right to make changes, without notice, in the products,
including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips
Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright,
or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask
work right infringement, unless otherwise specified. Applications that are described herein for any of these products are for illustrative purposes
only. Philips Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing
or modification.
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or systems where malfunction of a Philips Semiconductors and Philips Electronics North America Corporation Product can reasonably be expected
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Semiconductors and Philips Electronics North America Corporation Products for use in such applications do so at their own risk and agree to fully
indemnify Philips Semiconductors and Philips Electronics North America Corporation for any damages resulting from such improper use or sale.
This data sheet contains preliminary data, and supplementary data will be published at a later date. Philips
Semiconductors reserves the right to make changes at any time without notice in order to improve design
and supply the best possible product.
Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Sunnyvale, California 94088–3409
Telephone 800-234-7381
DEFINITIONS
Data Sheet Identification Product Status Definition
Objective Specification
Preliminary Specification
Product Specification
Formative or in Design
Preproduction Product
Full Production
This data sheet contains the design target or goal specifications for product development. Specifications
may change in any manner without notice.
This data sheet contains Final Specifications. Philips Semiconductors reserves the right to make changes
at any time without notice, in order to improve design and supply the best possible product.
Copyright Philips Electronics North America Corporation 1997
All rights reserved. Printed in U.S.A.
