The ACT138 is an advanced high-speed CMOS 3
TO 8 LINE DECODER (INVERTING) fabricated
with sub-micron silicon gate and double-layer
metal wiring C
2
MOS technology.
If the device is enabled, 3 binary select inputs (A,
B and C) determine which one of the outputs will
go low. If enable input G1 is held low or either
G2Aor G2G is held high, the decodingfunctionis
inhibitedand all the 8 outputs go to high.
B
(Plastic Package)
(Micro Package)
M
ORDERCODES:
74ACT138B
Three enable inputs are provided to ease
cascade connection and application of address
decodersfor memory systems.
It is ideal for low power applications mantaining
high speed operation similar to equivalent Bipolar
SchottkyTTL.
The device is designed to interface directly High
Speed CMOS systems with TTL, NMOS and
CMOSoutput voltage levels.
All inputs andoutputs areequipped with
protectioncircuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
This logic diagram has not be used to estimate propagation delays
2/8
Page 3
74ACT138
ABSOLUTE MAXIMUMRATINGS
Symb o lParame t erVal u eUni t
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
SymbolParameterValu eUnit
V
V
V
T
dt/dvInput Rise and Fall Time V
1) VINfrom0.8V to2.0 V
Supply Voltage-0.5 to +7V
CC
DC Input Voltage-0.5 to VCC+ 0.5V
I
DC Output Voltage-0.5 to VCC+ 0.5V
O
DC Input Diode Current± 20mA
IK
DC Output Diode Current± 20mA
DC Output Current± 50mA
O
DC VCCor Ground Current± 400mA
GND
Storage Temperature-65 to +150
stg
Lead Temperature (10 sec)300
L
Supply Voltage4.5 to 5.5V
CC
Input Voltage0 to V
I
Output Voltage0 to V
O
Operating Temperature:-40to +85
op
= 4.5 to 5.5V (note 1)8ns/V
CC
CC
CC
o
C
o
C
V
V
o
C
3/8
Page 4
74ACT138
DC SPECIFICATIONS
SymbolParameterTest Condit ionsValueUnit
T
V
CC
(V)
High Level Input Voltage4.5VO= 0.1 V or
V
IH
5.52.01.52.0
Low Level Input Voltage4.5VO= 0.1 V or
V
IL
5.51.50.80.8
High Level Output
V
OH
Voltage
4.5
5.5I
4.5I
5.5I
Low Level Output
V
OL
Voltage
4.5
5.5I
4.5I
5.5I
Input Leakage Current
I
I
Max ICC/Input5.5VI=VCC-2.1 V0.61.5mA
I
CCT
Quiescent Supply
I
CC
5.5
5.5VI=VCCor GND880µA
V
- 0.1 V
CC
- 0.1 V
V
CC
IO=-50 µA4.44.494.4
(*)
=
V
I
V
IH
V
IL
(*)
V
I
V
IH
V
IL
=-50 µA5.45.495.4
O
or
=-24 mA3.863.76
O
=-24 mA4.864.76
O
IO=50 µA0.0010.10.1
=
=50 mA0.0010.10.1
O
or
=24 mA0.360.44
O
=24 mA0.360.44
O
VI=VCCor GND±0.1±1µA
=25oC-40to85
A
Min.T yp . Max.Min.Max.
2.01.52.0
1.50.80.8
o
C
Current
Dynamic Output Current
I
OLD
OHD
(note 1, 2)
I
1) Maximum testduration 2ms, one output loaded at time
2) Incident wave switching is guaranteed on transmission lines with impedances as low as 50 Ω.
(*)All outputs loaded.
5.5V
= 1.65 V max75mA
OLD
V
= 3.85 V min-75mA
OHD
V
V
V
V
AC ELECTRICAL CHARACTERISTICS (CL= 50 pF, RL=500 Ω, Inputtr=tf=3ns)
SymbolParame terTest Conditi onValueUnit
t
Propagation Delay Time
PLH
t
A, B, C to Y
PHL
Propagation Delay Time
t
PLH
G1 to Y
t
PHL
Propagation Delay Time
t
PLH
t
G2A or G2B to Y
PHL
(*) Voltagerangeis5V± 0.5V
V
(V)
5.0
5.0
5.0
CC
(*)
(*)
(*)
T
=25oC-40to85
A
Min.T yp . Max.Min.Max.
5.010.011.0ns
5.010.011.0ns
5.510.011.0ns
o
C
CAPACITIVE CHARACTERISTICS
SymbolParameterTest Condit ionsValueUnit
T
=25oC-40to85
A
Min.T yp . Max.Min.Max.
4
Input Capacitance
C
IN
Power Dissipation
C
PD
V
CC
(V)
5.0
5.025pF
Capacitance (note 1)
1) CPDis defined as the value ofthe IC’s internal equivalent capacitance which is calculated from the operating current consumption without load. (Refer to
Test Circuit). Average operating current can be obtained by the following equation. I
(opr)= CPD• VCC•fIN+ICC/n (percircuit)
CC
o
C
pF
4/8
Page 5
74ACT138
WAVEFORM 1: PROPAGATION DELAYS FOR INVERTINGOUTPUTS (f=1MHz; 50% duty cycle)
WAVEFORM 2: PROPAGATION DELAYS FOR NON-INVERTING OUTPUTS (f=1MHz; 50%duty cycle)
5/8
Page 6
74ACT138
Plastic DIP16 (0.25) MECHANICAL DATA
DIM.
MIN.TYP.MAX.MIN.TYP.MAX.
a10.510.020
B0.771.650.0300.065
b0.50.020
b10.250.010
D200.787
E8.50.335
e2.540.100
e317.780.700
F7.10.280
I5.10.201
L3.30.130
Z1.270.050
mminch
6/8
P001C
Page 7
SO16 MECHANICAL DATA
74ACT138
DIM.
MIN.TYP.MAX.MIN.TYP.MAX.
A1.750.068
a10.10.20.0040.007
a21.650.064
b0.350.460.0130.018
b10.190.250.0070.010
C0.50.019
c145 (typ.)
D9.8100.3850.393
E5.86.20.2280.244
e1.270.050
e38.890.350
F3.84.00.1490.157
G4.65.30.1810.208
L0.51.270.0190.050
M0.620.024
S8 (max.)
mminch
P013H
7/8
Page 8
74ACT138
Information furnishedis believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsability for the
consequencesof use of such information nor for any infringement of patentsor other rights of third parties whichmay results from its use. No
licenseis granted byimplication or otherwise underany patentor patentrights ofSGS-THOMSONMicroelectronics. Specificationsmentioned
in this publicationare subject to change withoutnotice. This publication supersedes and replacesall information previously supplied.
SGS-THOMSONMicroelectronics productsarenot authorized for useascriticalcomponents in lifesupportdevices or systemswithoutexpress
writtenapproval of SGS-THOMSONMicroelectonics.
1997 SGS-THOMSONMicroelectronics- Printed in Italy - All Rights Reserved
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