TOSHIBA TC74VHC138F, TC74VHC138FN, TC74VHC138FT, TC74VHC138FK Technical data
TC74VHC138F/FN/FT/FK
TOSHIBA CMOS Digital Integrated Circuit Silicon Monolithic
TC74VHC138F,TC74VHC138FN,TC74VHC138FT,TC74VHC138FK
3-to-8 Line Decoder
The TC74VHC138 is an advanced high speed CMOS 3-to-8
DECODER fabricated with silicon gate 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 (
When enable input G1 is held low or either
high, decoding function is inhibited and all outputs go high.
G1,
2AG , and 2BG inputs are provided to ease cascade
connection and for use as an address decoder for memory
systems.
An input protection circuit ensures that 0 to 5.5 V can be
applied to the input pins without regard to the supply voltage.
This device can be used to interface 5 V to 3 V systems and two
supply systems such as battery back up. This circuit prevents
device destruction due to mismatched supply and input voltages.
0Y-7Y ) will go low.
2AG or 2BG is held
Features
Note: xxxFN (JEDEC SOP) is not available in
Japan.
TC74VHC138F
TC74VHC138FN
• High speed: t
• Low power dissipation: I
• High noise immunity: V
• Power down protection is provided on all inputs.
• Balanced propagation delays: t
• Wide operating voltage range: V
• Pin and function compatible with 74ALS138
= 5.7 ns (typ.) at VCC = 5 V
pd
= 4 μA (max) at Ta = 25°C
CC
NIH
= V
NIL
pLH
CC (opr)
= 28% V
∼
t
−
CC (min)
pHL
= 2 V to 5.5 V
TC74VHC138FT
TC74VHC138FK
Weight
SOP16-P-300-1.27A : 0.18 g (typ.)
SOL16-P-150-1.27 : 0.13 g (typ.)
TSSOP16-P-0044-0.65A : 0.06 g (typ.)
VSSOP16-P-0030-0.50 : 0.02 g (typ.)
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Pin Assignment
TC74VHC138F/FN/FT/FK
A
1
B
2
C
3
2AG
4
2BG
5
G1
6
7Y
7
GND
8 9
(top view)
IEC Logic Symbol
BIN/OCT
1
2
4
&
EN
2AG
2BG
G1
(1)
A
(2)
B
(3)
C
(6)
(4)
(5)
Truth Table
VCC 16
15
0Y
14
1Y
13
2Y
12
3Y
11
4Y
10
5Y
6Y
(15)
0
(14)
1
(13)
2
(12)
3
(11)
4
(10)
5
6
7
(9)
(7)
0Y
1Y
2Y
3Y
4Y
5Y
6Y
7Y
2AG
2BG
G1
(1)
A
(2)
B
(3)
C
(6)
(4)
(5)
DMUX
0
0
G
7
2
&
(15)
0
(14)
1
(13)
2
(12)
3
(11)
4
(10)
5
6
7
(9)
(7)
0Y
1Y
2Y
3Y
4Y
5Y
6Y
7Y
Inputs Outputs
Enable Select
G1
L X X X X X H H H H H H H H None
X H X X X X H H H H H H H H None
X X H X X X H H H H H H H H None
H L L L L L L H H H H H H H 0Y
H L L L L H H L H H H H H H 1Y
H L L L H L H H L H H H H H 2Y
H L L L H H H H H L H H H H 3Y
H L L H L L H H H H L H H H 4Y
H L L H L H H H H H H L H H 5Y
H L L H H L H H H H H H L H 6Y
H L L H H H H H H H H H H L 7Y
C B A
B2G
A2G
0Y 1Y 2Y 3Y 4Y 5Y 6Y 7Y
X: Don’t care
Selected
Output
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Logic Diagram
1
A
G1
2
B
3
C
4
A2G
5
B2G
6
Select
inputs
Enable
inputs
Absolute Maximum Ratings (Note)
TC74VHC138F/FN/FT/FK
15
0Y
14
1Y
13
2Y
12
11
10
9
7
3Y
4Y
5Y
6Y
7Y
Data
outputs
Characteristics Symbol Rating Unit
Supply voltage range VCC −0.5 to 7.0 V
DC input voltage VIN −0.5 to 7.0 V
DC output voltage V
Input diode current IIK −20 mA
Output diode current IOK ±20 mA
DC output current I
DC VCC/ground current ICC ±75 mA
Power dissipation PD 180 mW
Storage temperature T
−0.5 to VCC + 0.5 V
OUT
±25 mA
OUT
−65 to 150 °C
stg
Note: 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).
Operating Ranges (Note)
Characteristics Symbol Rating Unit
Supply voltage V
Input voltage V
Output voltage V
Operating temperature T
Input rise and fall time dt/dv
CC
IN
OUT
opr
0 to 100 (V
2.0 to 5.5 V
0 to 5.5
0 to V
CC
−40 to 85 °C
= 3.3 ± 0.3 V)
CC
0 to 20 (V
= 5 ± 0.5 V)
CC
V
V
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.
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