74LVX138 Low Voltage 1-of-8 Decoder/Demultiplexer
June 1993
Revised October 2003
74LVX138
Low Voltage 1-of-8 Decoder/Demultiplexer
General Description
The LVX138 is a high-speed 1-of-8 decoder/demultiplexer.
This device is ideally suited for high-speed bipolar memory
chip select address decoding. The multiple input enables
allow parallel expansion to a 1-of-24 decoder using just
three LVX138 devices or a 1-of-32 decoder using four
LVX138 devices and one inverter.
Features
s
Input voltage level translation from 5V to 3V
s
Ideal for low power/low noise 3.3V applications
s
Guaranteed simultaneous switching noise level and
dynamic threshold performance
Ordering Code:
Order Number
74LVX138M
74LVX138SJ
74LVX138MTC
Package Number
M16A
M16D
MTC16
Package Description
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
Devices also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.
Logic Symbols
Connection Diagram
Pin Descriptions
IEEE/IEC
Pin Names
A
0
–A
2
E
1
– E
2
E
3
O
0
–O
7
Description
Address Inputs
Enable Inputs
Enable Input
Outputs
© 2003 Fairchild Semiconductor Corporation
DS011615
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74LVX138
Functional Description
The LVX138 high-speed 1-of-8 decoder/demultiplexer
accepts three binary weighted inputs (A
0
, A
1
, A
2
) and,
when enabled, provides eight mutually exclusive active-
LOW outputs (O
0
–O
7
). The LVX138 features three Enable
inputs, two active-LOW (E
1
, E
2
) and one active-HIGH (E
3
).
All outputs will be HIGH unless E
1
and E
2
are LOW and E
3
is HIGH.
The LVX138 can be used as an 8-output demultiplexer by
using one of the active LOW Enable inputs as the data
input and the other Enable inputs as strobes. The Enable
inputs which are not used must be permanently tied to their
appropriate active-HIGH or active-LOW state.
Truth Table
Inputs
E
1
H
X
X
L
L
L
L
L
L
L
L
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial
Outputs
A
1
X
X
X
L
L
H
H
L
L
H
H
A
2
X
X
X
L
L
L
L
H
H
H
H
O
0
H
H
H
L
H
H
H
H
H
H
H
O
1
H
H
H
H
L
H
H
H
H
H
H
O
2
H
H
H
H
H
L
H
H
H
H
H
O
3
H
H
H
H
H
H
L
H
H
H
H
O
4
H
H
H
H
H
H
H
L
H
H
H
O
5
H
H
H
H
H
H
H
H
L
H
H
O
6
H
H
H
H
H
H
H
H
H
L
H
O
7
H
H
H
H
H
H
H
H
H
H
L
E
2
X
H
X
L
L
L
L
L
L
L
L
E
3
X
X
L
H
H
H
H
H
H
H
H
A
0
X
X
X
L
H
L
H
L
H
L
H
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.
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2
74LVX138
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
CC
)
DC Input Diode Current (I
IK
)
V
I
= −
0.5V
DC Input Voltage (V
I
)
DC Output Diode Current (I
OK
)
V
O
= −
0.5V
V
O
=
V
CC
+
0.5V
DC Output Voltage (V
O
)
DC Output Source
or Sink Current (I
O
)
DC V
CC
or Ground Current (I
CC
or I
GND
)
Storage Temperature (T
STG
)
Power Dissipation
−
0.5V to
+
7.0V
−
20 mA
−
0.5V to 7V
−
20 mA
+
20 mA
−
0.5V to V
CC
+
0.5V
±
25 mA
±
75 mA
−
65
°
C to
+
150
°
C
180 mW
Recommended Operating
Conditions
(Note 2)
Supply Voltage (V
CC
)
Input Voltage (V
I
)
Output Voltage (V
O
)
Operating Temperature (T
A
)
Input Rise and Fall Time (
∆
t/
∆
V)
2.0V to 3.6V
0V to 5.5V
0V to V
CC
−
40
°
C to
+
85
°
C
0 ns/V to 100 ns/V
Note 1:
The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Note 2:
Unused inputs must be held HIGH or LOW. They may not float.
DC Electrical Characteristics
Symbol
V
IH
Parameter
HIGH Level
Input Voltage
V
IL
LOW Level
Input Voltage
V
OH
HIGH Level
Output Voltage
V
OL
LOW Level
Output Voltage
I
IN
I
CC
Input Leakage Current
Quiescent Supply Current
V
CC
2.0
3.0
3.6
2.0
3.0
3.6
2.0
3.0
3.0
2.0
3.0
3.0
3.6
3.6
1.9
2.9
2.58
0.0
0.0
0.1
0.1
0.36
±0.1
4.0
2.0
3.0
T
A
= +25°C
Min
1.5
2.0
2.4
0.5
0.8
0.8
1.9
2.9
2.48
0.1
0.1
0.44
±1.0
40.0
µA
µA
V
V
Typ
Max
T
A
= −40°C
to
+85°C
Min
1.5
2.0
2.4
0.5
0.8
0.8
V
IN
=
V
IL
or V
IH
I
OH
= −50 µA
I
OH
= −50 µA
I
OH
= −4
mA
V
IN
=
V
IL
or V
IH
I
OL
=
50
µA
I
OL
=
50
µA
I
OL
=
4 mA
V
IN
=
5.5V or GND
V
IN
=
V
CC
or GND
V
V
Max
Units
Conditions
Noise Characteristics
(Note 3)
Symbol
V
OLP
V
OLV
V
IHD
V
ILD
Parameter
Quiet Output Maximum Dynamic V
OL
Quiet Output Minimum Dynamic V
OL
Minimum HIGH Level Dynamic Input Voltage
Maximum LOW Level Dynamic Input Voltage
V
CC
(V)
3.3
3.3
3.3
3.3
T
A
=
25°C
Typ
0.3
−0.3
Limit
0.5
−0.5
2.0
0.8
Units
V
V
V
V
C
L
(pF)
50
50
50
50
Note 3:
Input t
r
=
t
f
=
3 ns
3
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74LVX138
AC Electrical Characteristics
Symbol
t
PLH
t
PHL
Parameter
Propagation
Delay Time
A
n
to O
n
t
PLH
t
PHL
Propagation
Delay Time
E
1
or E
2
to O
n
t
PLH
t
PHL
Propagation
Delay Time
E
3
to O
n
t
OSHL
t
OSLH
Output to Output
Skew (Note 4)
3.3
±
0.3
2.7
3.3
3.3
±
0.3
2.7
3.3
±
0.3
2.7
V
CC
(V)
2.7
Min
T
A
= +25°C
Typ
7.1
9.6
5.5
8.0
8.8
11.3
6.9
9.4
8.7
11.2
6.8
9.3
Max
13.8
17.3
8.8
12.3
16.0
19.5
10.4
13.9
16.3
19.8
10.6
14.1
1.5
1.5
T
A
= −40°C
to
+85°C
Min
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Max
16.5
20.0
10.5
14.0
18.5
22.0
11.5
15.0
19.5
23.0
12.5
16.0
1.5
1.5
ns
ns
ns
ns
Units
CL (pF)
15
50
15
50
15
50
15
50
15
50
15
50
50
Note 4:
Parameter guaranteed by design. t
OSLH
=
|t
PLHm
–t
PLHn
|, t
OSHL
=
|t
PHLm
–t
PHLn
|
Capacitance
Symbol
C
IN
C
PD
Input Capacitance
Power Dissipation Capacitance (Note 5)
Parameter
T
A
= +25°C
Min
Typ
4
34
Max
10
T
A
= −40°C
to
+85°C
Min
Max
10
Units
pF
pF
Note 5:
C
PD
is defined as the value of the internal equivalent capacitance which is calculated from the operating current consumption without load.
Average operating current can be obtained by the equation: C
PD
×
V
CC
×
I
IN
+
I
CC
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4
74LVX138
Physical Dimensions
inches (millimeters) unless otherwise noted
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
Package Number M16A
5
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