TC74AC138P/F/FN/FT
TOSHIBA CMOS Digital Integrated Circuit
Silicon Monolithic
TC74AC138P,TC74AC138F,TC74AC138FN,TC74AC138FT
3-to-8 Line Decoder
The TC74AC138 is an advanced high speed CMOS 3-to-8 LINE
DECODER fabricated with silicon gate and double-layer metal
wiring C2MOS technology.
It achieves the high speed operation similar to equivalent
Bipolar Schottky TTL while maintaining the CMOS low power
dissipation.
When the device is enabled, 3 Binary Select inputs (A, B and
C) determine which one of the outputs (
Y 0
-
Y7
) will go low.
When enable input G1 is held low or either
G 2 A
or
G2B
is
held high, decoding function is inhibited and all outputs go high.
G1,
G 2 A
, and
G2B
inputs are provided to ease cascade
connection and for use as an address decoder for memory
systems.
All inputs are equipped with protection circuits against static
discharge or transient excess voltage.
Note: xxxFN (JEDEC SOP) is not available in
Japan.
TC74AC138P
TC74AC138F
Features
•
•
•
•
High speed: t
pd
= 5.9 ns (typ.) at V
CC
= 5 V
Low power dissipation: I
CC
= 8
μA
(max) at Ta = 25°C
High noise immunity: V
NIH
= V
NIL
= 28% V
CC
(min)
Symmetrical output impedance: |I
OH
| = I
OL
= 24 mA (min)
Capability of driving 50
Ω
transmission lines.
∼
Balanced propagation delays: t
pLH
−
t
pHL
Wide operating voltage range: V
CC (opr)
= 2 to 5.5 V
Pin and function compatible with 74F138
TC74AC138FN
•
•
•
TC74AC138FT
Weight
DIP16-P-300-2.54A
SOP16-P-300-1.27A
SOL16-P-150-1.27
TSSOP16-P-0044-0.65A
: 1.00 g (typ.)
: 0.18 g (typ.)
: 0.13 g (typ.)
: 0.06 g (typ.)
1
2007-10-01
TC74AC138P/F/FN/FT
Pin Assignment
A
B
C
G2A
1
2
3
4
5
6
7
8
(top view)
16
15
14
13
12
11
10
9
V
CC
Y0
Y1
Y2
Y3
G2B
G1
Y7
GND
Y4
Y5
Y6
IEC Logic Symbol
A
B
C
(1)
(2)
(3)
1
2
4
&
EN
BIN/OCT
0
1
2
3
4
5
6
7
(15)
(14)
(13)
(12)
(11)
(10)
(9)
(7)
Y0
Y1
Y2
A
B
C
(1)
(2)
(3)
0
2
&
DMUX
0
G
7
0
1
2
3
4
5
6
7
(15)
(14)
(13)
(12)
(11)
(10)
(9)
(7)
Y0
Y1
Y2
G1
G2A
G2B
(6)
(4)
(5)
Y3
Y4
Y5
Y6
Y7
G1
G2A
G2B
(6)
(4)
(5)
Y3
Y4
Y5
Y6
Y7
Truth Table
Inputs
Enable
G1
G2 A
Outputs
Select
G2B
X
X
H
L
L
L
L
L
L
L
L
C
B
A
Y0
H
H
H
L
H
H
H
H
H
H
H
Y1
H
H
H
H
L
H
H
H
H
H
H
Y2
H
H
H
H
H
L
H
H
H
H
H
Y3
H
H
H
H
H
H
L
H
H
H
H
Y4
H
H
H
H
H
H
H
L
H
H
H
Y5
H
H
H
H
H
H
H
H
L
H
H
Y6
H
H
H
H
H
H
H
H
H
L
H
Y7
H
H
H
H
H
H
H
H
H
H
L
Selected
Output
None
None
None
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
L
X
X
H
H
H
H
H
H
H
H
X
H
X
L
L
L
L
L
L
L
L
X
X
X
L
L
L
L
H
H
H
H
X
X
X
L
L
H
H
L
L
H
H
X
X
X
L
H
L
H
L
H
L
H
X: Don’t care
2
2007-10-01
TC74AC138P/F/FN/FT
Logic Diagram
15
14
13
12
11
10
9
7
Enable
inputs
G2 A
G 2B
Y0
Y1
Y2
A
1
Select
inputs
B
2
Y3
Y4
Data
outputs
C
3
Y5
Y6
Y7
4
5
6
G1
Absolute Maximum Ratings (Note 1)
Characteristics
Supply voltage range
DC input voltage
DC output voltage
Input diode current
Output diode current
DC output current
DC V
CC
/ground current
Power dissipation
Storage temperature
Symbol
V
CC
V
IN
V
OUT
I
IK
I
OK
I
OUT
I
CC
P
D
T
stg
Rating
−0.5
to 7.0
−0.5
to V
CC
+ 0.5
−0.5
to V
CC
+ 0.5
±20
±50
±50
±200
500 (DIP) (Note 2)/180 (SOP/TSSOP)
−65
to 150
Unit
V
V
V
mA
mA
mA
mA
mW
°C
Note 1: Exceeding any of the absolute maximum ratings, even briefly, lead to deterioration in IC performance or
even destruction.
Using continuously under heavy loads (e.g. the application of high temperature/current/voltage and the
significant change in temperature, etc.) may cause this product to decrease in the reliability significantly
even if the operating conditions (i.e. operating temperature/current/voltage, etc.) are within the absolute
maximum ratings and the operating ranges.
Please design the appropriate reliability upon reviewing the Toshiba Semiconductor Reliability Handbook
(“Handling Precautions”/Derating Concept and Methods) and individual reliability data (i.e. reliability test
report and estimated failure rate, etc).
Note 2: 500 mW in the range of Ta =
−40
to 65°C. From Ta = 65 to 85°C a derating factor of
−10
mW/°C should be
applied up to 300 mW.
Operating Ranges (Note)
Characteristics
Supply voltage
Input voltage
Output voltage
Operating temperature
Input rise and fall time
Symbol
V
CC
V
IN
V
OUT
T
opr
dt/dV
Rating
2.0 to 5.5
0 to V
CC
0 to V
CC
−40
to 85
0 to 100 (V
CC
= 3.3 ± 0.3 V)
0 to 20 (V
CC
= 5 ± 0.5 V)
Unit
V
V
V
°C
ns/V
Note:
The operating ranges must be maintained to ensure the normal operation of the device.
Unused inputs must be tied to either VCC or GND.
3
2007-10-01
TC74AC138P/F/FN/FT
Electrical Characteristics
DC Characteristics
Ta = 25°C
Characteristics
Symbol
Test Condition
V
CC
(V)
2.0
High-level input
voltage
V
IH
―
3.0
5.5
2.0
Low-level input
voltage
V
IL
―
3.0
5.5
2.0
I
OH
=
−50 μA
High-level output
voltage
V
OH
V
IN
= V
IH
or
I
OH
=
−4
mA
V
IL
I
OH
=
−24
mA
I
OH
=
−75
mA
(Note)
3.0
4.5
3.0
4.5
5.5
2.0
I
OL
= 50
μA
Low-level output
voltage
V
OL
V
IN
= V
IH
or
I
OL
= 12 mA
V
IL
I
OL
= 24 mA
I
OL
= 75 mA
Input leakage
current
Quiescent supply
current
I
IN
I
CC
V
IN
= V
CC
or GND
V
IN
= V
CC
or GND
(Note)
3.0
4.5
3.0
4.5
5.5
5.5
5.5
Min
1.5
2.10
3.85
―
―
―
1.9
2.9
4.4
2.58
3.94
―
―
―
―
―
―
―
―
―
Typ.
―
―
―
―
―
―
2.0
3.0
4.5
―
―
―
0.0
0.0
0.0
―
―
―
―
―
Max
―
―
―
0.50
0.90
1.65
―
―
―
―
―
―
0.1
0.1
0.1
0.36
0.36
―
±0.1
8.0
Ta =
−40
to
85°C
Min
1.5
2.10
3.85
―
―
―
1.9
2.9
4.4
2.48
3.80
3.85
―
―
―
―
―
―
―
―
Max
―
―
―
0.50
0.90
1.65
―
―
―
―
―
―
0.1
0.1
0.1
0.44
0.44
1.65
±1.0
80.0
μA
μA
V
V
V
V
Unit
Note:
This spec indicates the capability of driving 50
Ω
transmission lines.
One output should be tested at a time for a 10 ms maximum duration.
4
2007-10-01
TC74AC138P/F/FN/FT
AC Characteristics
(C
L
= 50 pF, R
L
= 500
Ω,
input: t
r
= t
f
= 3 ns)
Characteristics
Propagation delay
time
(A, B, C- Y )
Propagation delay
time
(G1- Y )
Propagation delay
time
( G2 - Y )
Input capacitance
Power dissipation
capacitance
Symbol
Test Condition
V
CC
(V)
t
pLH
t
pHL
t
pLH
t
pHL
t
pLH
t
pHL
C
IN
C
PD
―
3.3 ± 0.3
5.0 ± 0.5
3.3 ± 0.3
5.0 ± 0.5
3.3 ± 0.3
5.0 ± 0.5
―
(Note)
Min
―
―
―
―
―
―
―
―
Ta = 25°C
Typ.
8.5
6.4
7.5
6.1
8.8
7.2
5
143
Max
14.2
9.2
12.8
8.9
15.0
10.5
10
―
Ta =
−40
to
85°C
Min
1.0
1.0
1.0
1.0
1.0
1.0
―
―
Max
16.3
10.5
14.7
10.2
17.3
12.0
10
―
ns
Unit
―
ns
―
ns
pF
pF
Note:
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:
I
CC (opr)
= C
PD
·V
CC
·f
IN
+ I
CC
5
2007-10-01
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