74HC138; 74HCT138
Rev. 8 — 7 April 2020
3-to-8 line decoder/demultiplexer; inverting
Product data sheet
1. General description
The 74HC138; 74HCT138 decodes three binary weighted address inputs (A0, A1 and A2) to
eight mutually exclusive outputs (Y0 to Y7). The device features three enable inputs (E1, E2 and
E3). Every output will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enable
function allows easy parallel expansion to a 1-of-32 (5 to 32 lines) decoder with just four '138 ICs
and one inverter. The '138 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. Inputs include
clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in
excess of V
CC
.
2. Features and benefits
•
•
Complies with JEDEC standard no. 7A
Input levels:
•
For 74HC138: CMOS level
•
For 74HCT138: TTL level
Demultiplexing capability
Multiple input enable for easy expansion
Ideal for memory chip select decoding
Active LOW mutually exclusive outputs
ESD protection:
•
HBM JESD22-A114F exceeds 2000 V
•
MM JESD22-A115-A exceeds 200 V
Multiple package options
Specified from -40 °C to +85 °C and from -40 °C to +125 °C
•
•
•
•
•
•
•
3. Ordering information
Table 1. Ordering information
Type number
Package
Temperature range
74HC138D
74HCT138D
74HC138DB
74HCT138DB
74HC138PW
74HCT138PW
74HC138BQ
74HCT138BQ
-40 °C to +125 °C
-40 °C to +125 °C
TSSOP16
-40 °C to +125 °C
SSOP16
-40 °C to +125 °C
Name
SO16
Description
plastic small outline package; 16 leads;
body width 3.9 mm
plastic shrink small outline package; 16 leads;
body width 5.3 mm
plastic thin shrink small outline package; 16 leads;
body width 4.4 mm
Version
SOT109-1
SOT338-1
SOT403-1
SOT763-1
DHVQFN16 plastic dual in-line compatible thermal enhanced
very thin quad flat package; no leads; 16 terminals;
body 2.5 × 3.5 × 0.85 mm
Nexperia
74HC138; 74HCT138
3-to-8 line decoder/demultiplexer; inverting
4. Functional diagram
Y0
1
2
3
A0
A1
A2
3-to-8
DECODER
ENABLE
EXITING
Y1
Y2
Y3
Y4
Y5
Y6
Y7
4
5
6
E1
E2
E3
mna372
15
14
13
12
11
10
9
7
1
2
3
E1
E2
E3
A0
A1
A2
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
mna370
15
14
13
12
11
10
9
7
4
5
6
Fig. 1.
Logic symbol
A2
Fig. 2.
Functional diagram
Y7
Y6
Y5
A1
A0
Y4
E1
Y3
E2
Y2
E3
Y1
Y0
001aae059
Fig. 3.
Logic diagram
74HC_HCT138
All information provided in this document is subject to legal disclaimers.
©
Nexperia B.V. 2020. All rights reserved
Product data sheet
Rev. 8 — 7 April 2020
2 / 16
Nexperia
74HC138; 74HCT138
3-to-8 line decoder/demultiplexer; inverting
5. Pinning information
5.1. Pinning
74HC138
74HCT138
terminal 1
index area
A1
2
3
4
5
6
7
8
GND
Y6
9
GND
(1)
16 V
CC
15 Y0
14 Y1
13 Y2
12 Y3
11 Y4
10 Y5
A0
1
74HC138
74HCT138
A0
A1
A2
E1
E2
E3
Y7
GND
1
2
3
4
5
6
7
8
aaa-028342
A2
E1
E2
16 V
CC
15 Y0
14 Y1
13 Y2
12 Y3
11 Y4
10 Y5
9
Y6
74HC138
74HCT138
A0
A1
A2
E1
E2
E3
Y7
GND
1
2
3
4
5
6
7
8
aaa-028343
E3
Y7
16 V
CC
15 Y0
14 Y1
13 Y2
12 Y3
11 Y4
10 Y5
9
Y6
001aae060
Transparent top view
Fig. 4.
Pin configuration SOT109-1
(SO16)
Fig. 5.
Pin configuration SOT338-1
(SSOP16) and SOT403-1
(TSSOP16)
(1) This is not a ground
pin. There is no electrical
or mechanical requirement
to solder the pad. In case
soldered, the solder land
should remain floating or
connected to GND.
Fig. 6.
Pin configuration SOT763-1
(DHVQFN16)
5.2. Pin description
Table 2. Pin description
Symbol
A0, A1, A2
E1, E2
E3
Y0, Y1, Y2, Y3, Y4, Y5, Y6, Y7
GND
V
CC
Pin
1, 2, 3
4, 5
6
15, 14, 13, 12, 11, 10, 9, 7
8
16
Description
address input
enable input (active LOW)
enable input (active HIGH)
output
ground (0 V)
supply voltage
74HC_HCT138
All information provided in this document is subject to legal disclaimers.
©
Nexperia B.V. 2020. All rights reserved
Product data sheet
Rev. 8 — 7 April 2020
3 / 16
Nexperia
74HC138; 74HCT138
3-to-8 line decoder/demultiplexer; inverting
6. Functional description
Table 3. Function table
H = HIGH voltage level; L = LOW voltage level; X = don’t care.
Control
E1
H
X
X
L
E2
X
H
X
L
E3
X
X
L
H
L
L
L
L
H
H
H
H
L
L
H
H
L
L
H
H
L
H
L
H
L
H
L
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
L
H
H
H
H
H
H
L
H
H
H
H
H
H
L
H
H
H
H
H
H
L
H
H
H
H
H
H
L
H
H
H
H
H
H
L
H
H
H
H
H
H
L
H
H
H
H
H
H
H
Input
A2
X
A1
X
A0
X
Output
Y7
H
Y6
H
Y5
H
Y4
H
Y3
H
Y2
H
Y1
H
Y0
H
7. Limiting values
Table 4. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages are referenced to GND (ground = 0 V).
Symbol Parameter
V
CC
I
IK
I
OK
I
O
I
CC
I
GND
T
stg
P
tot
[1]
Conditions
V
I
< -0.5 V or V
I
> V
CC
+ 0.5 V
V
O
< -0.5 V or V
O
> V
CC
+ 0.5 V
V
O
= -0.5 V to (V
CC
+ 0.5 V)
Min
-0.5
-
-
-
-
-50
-65
[1]
-
Max
+7
±20
±20
±25
50
-
+150
500
Unit
V
mA
mA
mA
mA
mA
°C
mW
supply voltage
input clamping current
output clamping current
output current
quiescent supply current
ground current
storage temperature
total power dissipation
For SOT109-1 (SO16) package: P
tot
derates linearly with 12.4 mW/K above 110 °C.
For SOT338-1 (SSOP16) package: P
tot
derates linearly with 8.5 mW/K above 91 °C.
For SOT403-1 (TSSOP16) package: P
tot
derates linearly with 8.5 mW/K above 91 °C.
For SOT763-1 (DHVQFN16) package: P
tot
derates linearly with 11.2 mW/K above 106 °C.
74HC_HCT138
All information provided in this document is subject to legal disclaimers.
©
Nexperia B.V. 2020. All rights reserved
Product data sheet
Rev. 8 — 7 April 2020
4 / 16
Nexperia
74HC138; 74HCT138
3-to-8 line decoder/demultiplexer; inverting
8. Recommended operating conditions
Table 5. Recommended operating conditions
Voltages are referenced to GND (ground = 0 V)
Symbol Parameter
V
CC
V
I
V
O
T
amb
Δt/ΔV
supply voltage
input voltage
output voltage
ambient temperature
input transition rise and fall rate V
CC
= 2.0 V
V
CC
= 4.5 V
V
CC
= 6.0 V
Conditions
Min
2.0
0
0
-40
-
-
-
74HC138
Typ
5.0
-
-
+25
-
1.67
-
Max
6.0
V
CC
V
CC
+125
625
139
83
Min
4.5
0
0
-40
-
-
-
74HCT138
Typ
5.0
-
-
+25
-
1.67
-
Max
5.5
V
CC
V
CC
+125
-
139
-
V
V
V
°C
ns/V
ns/V
ns/V
Unit
9. Static characteristics
Table 6. Static characteristics
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Symbol Parameter
Conditions
T
amb
= 25 °C
Min
74HC138
V
IH
HIGH-level
input voltage
V
CC
= 2.0 V
V
CC
= 4.5 V
V
CC
= 6.0 V
V
IL
LOW-level
input voltage
V
CC
= 2.0 V
V
CC
= 4.5 V
V
CC
= 6.0 V
V
OH
V
I
= V
IH
or V
IL
HIGH-level
output voltage
I
O
= -20 μA; V
CC
= 2.0 V
I
O
= -20 μA; V
CC
= 4.5 V
I
O
= -20 μA; V
CC
= 6.0 V
I
O
= -4.0 mA; V
CC
= 4.5 V
I
O
= -5.2 mA; V
CC
= 6.0 V
V
OL
V
I
= V
IH
or V
IL
LOW-level
output voltage
I
O
= 20 μA; V
CC
= 2.0 V
I
O
= 20 μA; V
CC
= 4.5 V
I
O
= 20 μA; V
CC
= 6.0 V
I
O
= 4.0 mA; V
CC
= 4.5 V
I
O
= 5.2 mA; V
CC
= 6.0 V
I
I
I
CC
C
I
input leakage
current
V
I
= V
CC
or GND; V
CC
= 6.0 V
1.5
3.15
4.2
-
-
-
1.9
4.4
5.9
3.98
5.48
-
-
-
-
-
-
-
-
1.2
2.4
3.2
0.8
2.1
2.8
2.0
4.5
6.0
4.32
5.81
0
0
0
0.15
0.16
-
-
3.5
-
-
-
0.5
1.35
1.8
-
-
-
-
-
0.1
0.1
0.1
0.26
0.26
±0.1
8.0
-
1.5
3.15
4.2
-
-
-
1.9
4.4
5.9
3.84
5.34
-
-
-
-
-
-
-
-
-
-
0.5
1.35
1.8
-
-
-
-
-
0.1
0.1
0.1
0.33
0.33
±1.0
80
1.5
3.15
4.2
-
-
-
1.9
4.4
5.9
3.7
5.2
-
-
-
-
-
-
-
-
-
-
0.5
1.35
1.8
-
-
-
-
-
0.1
0.1
0.1
0.4
0.4
±1.0
160
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
μA
μA
pF
Typ
Max
T
amb
= -40 °C
to +85 °C
Min
Max
T
amb
= -40 °C
to +125 °C
Min
Max
Unit
supply current V
I
= V
CC
or GND; I
O
= 0 A;
V
CC
= 6.0 V
input
capacitance
74HC_HCT138
All information provided in this document is subject to legal disclaimers.
©
Nexperia B.V. 2020. All rights reserved
Product data sheet
Rev. 8 — 7 April 2020
5 / 16
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