HD74LV138A
3-to-8 line Decoder / Demultiplexers
ADE-205-261 (Z)
1st Edition
March 1999
Description
The HD74LV138A is designed to be used in high-performance memory-decoding or data-routing
applications requiring very short propagation delay times. The conditions at the binary-select inputs and
the three enable inputs select one of eight input lines.
Two active-low and one active-high enable inputs reduce the need for external gates or inverters when
expanding. A 24-line decoder can be implemented without external inverters and a 32-line decoder
requires only one inverter.
An enable input can be used as a data input for demultiplexing applications.
Low-voltage and high-speed operation is suitable for the battery-powered products (e.g., notebook
computers), and the low-power consumption extends the battery life.
Features
V
CC
= 2.0 V to 5.5 V operation
All inputs V
IH
(Max.) = 5.5 V (@V
CC
= 0 V to 5.5 V)
All outputs V
O
(Max.) = 5.5 V (@V
CC
= 0 V)
Typical V
OL
ground bounce < 0.8 V (@V
CC
= 3.3 V, Ta = 25
C)
Typical V
OH
undershoot > 2.3 V (@V
CC
= 3.3 V, Ta = 25
C)
Output current
6 mA (@V
CC
= 3.0 V to 3.6 V),
12 mA (@V
CC
= 4.5 V to 5.5 V)
HD74LV138A
3
Absolute Maximum Ratings
Item
Symbol
Ratings
Unit
Conditions
Supply voltage range
V
CC
0.5 to 7.0
V
Input voltage range*
1
V
I
0.5 to 7.0
V
Output voltage range*
1, 2
V
O
0.5 to V
CC
+ 0.5
V
Output: H or L
0.5 to 7.0
V
CC
: OFF
Input clamp current
I
IK
20
mA
V
I
< 0
Output clamp current
I
OK
50
mA
V
O
< 0 or V
O
> V
CC
Continuous output current
I
O
25
mA
V
O
= 0 to V
CC
Continuous current through
V
CC
or GND
I
CC
or I
GND
50
mA
Maximum power dissipation
at Ta = 25
C (in still air)*
3
P
T
785
mW
SOP
500
TSSOP
Storage temperature
Tstg
65 to 150
C
Notes: The absolute maximum ratings are values which must not individually be exceeded, and furthermore,
no two of which may be realized at the same time.
1. The input and output voltage ratings may
be exceeded if the input and output clamp-current
ratings are observed.
2. This value is limited to 5.5 V maximum.
3. The maximum package power dissipation was calculated using a junction temperature of 150
C.
HD74LV138A
4
Recommended Operating Conditions
Item
Symbol
Min
Max
Unit
Conditions
Supply voltage range
V
CC
2.0
5.5
V
Input voltage range
V
I
0
5.5
V
Output voltage range
V
O
0
V
CC
V
H or L
Output current
I
OH
--
50
A
V
CC
= 2.0 V
--
2
mA
V
CC
= 2.3 to 2.7 V
--
6
V
CC
= 3.0 to 3.6 V
--
12
V
CC
= 4.5 to 5.5 V
I
OL
--
50
A
V
CC
= 2.0 V
--
2
mA
V
CC
= 2.3 to 2.7 V
--
6
V
CC
= 3.0 to 3.6 V
--
12
V
CC
= 4.5 to 5.5 V
Input transition rise or fall rate
t/
v
0
200
ns/V
V
CC
= 2.3 to 2.7 V
0
100
V
CC
= 3.0 to 3.6 V
0
20
V
CC
= 4.5 to 5.5 V
Operating free-air temperature
Ta
40
85
C
Note:
Unused or floating inputs must be held high or low.
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