74HC238; 74HCT238
3-to-8 line decoder/demultiplexer
Rev. 03 — 16 July 2007
Product data sheet
1. General description
74HC238 and 74HCT238 are high-speed Si-gate CMOS devices and are pin compatible
with Low-Power Schottky TTL (LSTTL).
The 74HC238/74HCT238 decoders accept three binary weighted address inputs (A0, A1,
A2) and when enabled, provide 8 mutually exclusive active HIGH outputs (Y0 to Y7). The
74HC238/74HCT238 features three enable inputs: two active LOW (E1 and E2) and one
active HIGH (E3). Every output will be LOW unless E1 and E2 are LOW and E3 is HIGH.
This multiple enable function allows easy parallel expansion of the “238” to a 1-to-32 (5
lines to 32 lines) decoder with just four “238” ICs and one inverter. The “238” 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. Unused enable inputs must be
permanently tied to their appropriate active HIGH or LOW state.
The 74HC238/74HCT238 is similar to the 74HC138/74HCT138 but has non-inverting
outputs.
2. Features
I
I
I
I
I
I
I
Demultiplexing capability
Multiple input enable for easy expansion
Ideal for memory chip select decoding
Active HIGH mutually exclusive outputs
Multiple package options
Complies with JEDEC standard no. 7A
ESD protection:
N
HBM JESD22-A114E exceeds 2000 V
N
MM JESD22-A115-A exceeds 200 V
I
Specified from
−40 °C
to +85
°C
and from
−40 °C
to +125
°C
NXP Semiconductors
74HC238; 74HCT238
3-to-8 line decoder/demultiplexer
3. Ordering information
Table 1.
Ordering information
Package
Temperature range Name
74HC238N
74HC238D
74HC238DB
74HC238PW
74HC238BQ
−40 °C
to +125
°C
−40 °C
to +125
°C
−40 °C
to +125
°C
−40 °C
to +125
°C
−40 °C
to +125
°C
DIP16
SO16
SSOP16
TSSOP16
Description
plastic dual in-line package; 16 leads (300 mil)
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
SOT38-4
SOT109-1
SOT338-1
SOT403-1
Type number
DHVQFN16 plastic dual in-line compatible thermal enhanced very thin SOT763-1
quad flat package; no leads; 16 terminals;
body 2.5
×
3.5
×
0.85 mm
DIP16
SO16
SSOP16
TSSOP16
plastic dual in-line package; 16 leads (300 mil)
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
SOT38-4
SOT109-1
SOT338-1
SOT403-1
74HCT238N
74HCT238D
−40 °C
to +125
°C
−40 °C
to +125
°C
74HCT238DB
−40 °C
to +125
°C
74HCT238PW
−40 °C
to +125
°C
74HCT238BQ
−40 °C
to +125
°C
DHVQFN16 plastic dual in-line compatible thermal enhanced very thin SOT763-1
quad flat package; no leads; 16 terminals;
body 2.5
×
3.5
×
0.85 mm
4. Functional diagram
15
15
14
A0
A1
A2
1
2
3
3 TO 8
DECODER
13
ENABLE 12
EXITING 11
10
9
7
E1
E2
E3
4
5
6
001aag752
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
E1
E2
E3
4
5
6
A0
A1
A2
1
2
3
3 TO 8
DECODER
ENABLE
EXITING
14
13
12
11
10
9
7
001aag753
Fig 1. Logic symbol
Fig 2. Functional diagram
74HC_HCT238_3
© NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 03 — 16 July 2007
2 of 18
NXP Semiconductors
74HC238; 74HCT238
3-to-8 line decoder/demultiplexer
Y0
E1
E2
E3
Y1
Y2
Y3
Y4
Y5
A0
Y6
A1
A2
Y7
001aag754
Fig 3. Logic diagram
5. Pinning information
5.1 Pinning
74HC238
74HCT238
A0
A1
A2
E1
E2
E3
Y7
GND
1
2
3
4
5
6
7
8
001aag755
74HC238
74HCT238
16 V
CC
15 Y0
A1
14 Y1
13 Y2
12 Y3
11 Y4
10 Y5
9
Y6
A2
E1
E2
E3
Y7
2
3
4
5
6
7
8
GND
Y6
9
GND
(1)
terminal 1
index area
16 V
CC
15 Y0
14 Y1
13 Y2
12 Y3
11 Y4
10 Y5
A0
1
001aag756
Transparent top view
(1) The die substrate is attached to this pad using
conductive die attach material. It can not be used as
supply pin or input
Fig 4. Pin configuration DIP16, SO16, (T)SSOP16
Fig 5. Pin configuration DHVQFN16
74HC_HCT238_3
© NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 03 — 16 July 2007
3 of 18
NXP Semiconductors
74HC238; 74HCT238
3-to-8 line decoder/demultiplexer
5.2 Pin description
Table 2.
Symbol
A[0:2]
E1
E2
E3
Y[0:7]
GND
V
CC
Pin description
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 LOW)
enable input (active HIGH)
output (active HIGH)
ground (0 V)
supply voltage
6. Functional description
Table 3.
Inputs
E1
H
X
X
L
L
L
L
L
L
L
L
[1]
Function table
[1]
Outputs
E2
X
H
X
L
L
L
L
L
L
L
L
E3
X
X
L
H
H
H
H
H
H
H
H
A0
X
X
X
L
H
L
H
L
H
L
H
A1
X
X
X
L
L
H
H
L
L
H
H
A2
X
X
X
L
L
L
L
H
H
H
H
Y0
L
L
L
H
L
L
L
L
L
L
L
Y1
L
L
L
L
H
L
L
L
L
L
L
Y2
L
L
L
L
L
H
L
L
L
L
L
Y3
L
L
L
L
L
L
H
L
L
L
L
Y4
L
L
L
L
L
L
L
H
L
L
L
Y5
L
L
L
L
L
L
L
L
H
L
L
Y6
L
L
L
L
L
L
L
L
L
H
L
Y7
L
L
L
L
L
L
L
L
L
L
H
H = HIGH voltage level;
L = LOW voltage level;
X = don’t care.
74HC_HCT238_3
© NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 03 — 16 July 2007
4 of 18
NXP Semiconductors
74HC238; 74HCT238
3-to-8 line decoder/demultiplexer
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
V
CC
I
IK
I
OK
I
O
I
CC
I
GND
T
stg
P
tot
Parameter
supply voltage
input clamping current
output clamping current
output current
supply current
ground current
storage temperature
total power dissipation
DIP16 package
SO16, SSOP16, TSSOP16 and
DHVQFN16 packages
[1]
[2]
[3]
[2]
[3]
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
−0.5
V < V
O
< V
CC
+ 0.5 V
[1]
[1]
Min
−0.5
-
-
-
-
−50
−65
-
-
Max
+7
±20
±20
±25
50
-
+150
750
500
Unit
V
mA
mA
mA
mA
mA
°C
mW
mW
The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
For DIP16 packages: above 70
°C
the value of P
tot
derates linearly at 12 mW/K.
For SO16 packages: above 70
°C
the value of P
tot
derates linearly at 8 mW/K.
For SSOP16 and TSSOP16 packages: above 60
°C
the value of P
tot
derates linearly at 5.5 mW/K.
For DHVQFN16 packages: above 60
°C
the value of P
tot
derates linearly at 4.5 mW/K.
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
∆t/∆V
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
-
-
-
74HC238
Typ
5.0
-
-
-
-
1.67
-
Max
6.0
V
CC
V
CC
+125
625
139
83
Min
4.5
0
0
−40
-
-
-
74HCT238
Typ
5.0
-
-
-
-
1.67
-
Max
5.5
V
CC
V
CC
+125
-
139
-
V
V
V
°C
ns/V
ns/V
ns/V
Unit
74HC_HCT238_3
© NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 03 — 16 July 2007
5 of 18
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