74F538 1-of-8 Decoder with 3-STATE Outputs
April 1988
Revised January 2004
74F538
1-of-8 Decoder with 3-STATE Outputs
General Description
The 74F538 decoder/demultiplexer accepts three Address
(A
0
–A
2
) input signals and decodes them to select one of
eight mutually exclusive outputs. A polarity control input (P)
determines whether the outputs are active LOW or active
HIGH. A HIGH Signal on either of the active LOW Output
Enable (OE) inputs forces all outputs to the high imped-
ance state. Two active HIGH and two active LOW input
enables are available for easy expansion to 1-of 32 decod-
ing with four packages, or for data demultiplexing to 1-of-8
or 1-of-16 destinations.
Features
s
Output polarity control
s
Data demultiplexing capability
s
Multiple enables for expansion
s
3-STATE outputs
Ordering Code:
Order Number
74F538SC
74F538PC
Package Number
M20B
N20A
Package Description
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Logic Symbols
Connection Diagram
IEEE/IEC
© 2004 Fairchild Semiconductor Corporation
DS009551
www.fairchildsemi.com
74F538
Unit Loading/Fan Out
Pin Names
A
0
–A
2
E
1
, E
2
E
3
, E
4
P
OE
1
, OE
2
O
0
–O
7
Address Inputs
Enable Inputs (Active LOW)
Enable Inputs (Active HIGH)
Polarity Control Input
Output Enable Inputs (Active LOW)
3-STATE Outputs
Description
U.L.
HIGH/LOW
1.0/1.0
1.0/1.0
1.0/1.0
1.0/1.0
1.0/1.0
150/40 (33.3)
Input I
IH
/I
IL
Output I
OH
/I
OL
20
µ
A/
−
0.6 mA
20
µ
A/
−
0.6 mA
20
µ
A/
−
0.6 mA
20
µ
A/
−
0.6 mA
20
µ
A/
−
0.6 mA
−
3 mA/24 mA (20 mA)
Truth Table
Inputs
Function
High
Impedance
Disable
OE
1
H
X
L
L
L
L
Active HIGH
Output
(P
=
L)
L
L
L
L
L
L
L
L
Active LOW
Output
(P
=
H)
L
L
L
L
L
L
L
L
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial
Z
=
High Impedance
Outputs
E
4
X
X
X
X
X
L
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
A
2
X
X
X
X
X
X
L
L
L
L
H
H
H
H
L
L
L
L
H
H
H
H
A
1
X
X
X
X
X
X
L
L
H
H
L
L
H
H
L
L
H
H
L
L
H
H
A
0
X
X
X
X
X
X
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
H
L
L
L
L
L
L
L
L
H
H
H
H
H
H
H
L
H
L
L
L
L
L
L
H
L
H
H
H
H
H
H
L
L
H
L
L
L
L
L
H
H
L
H
H
H
H
H
L
L
L
H
L
L
L
L
H
H
H
L
H
H
H
H
L
L
L
L
H
L
L
L
H
H
H
H
L
H
H
H
L
L
L
L
L
H
L
L
H
H
H
H
H
L
H
H
L
L
L
L
L
L
H
L
H
H
H
H
H
H
L
H
L
L
L
L
L
L
L
H
H
H
H
H
H
H
H
L
Outputs Equal P Input
O
0
Z
Z
O
1
Z
Z
O
2
Z
Z
O
3
Z
Z
O
4
Z
Z
O
5
Z
Z
O
6
Z
Z
O
7
Z
Z
OE
2
X
H
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
E
1
X
X
H
X
X
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
E
2
X
X
X
H
X
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
E
3
X
X
X
X
L
X
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
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2
74F538
Absolute Maximum Ratings
(Note 1)
Storage Temperature
Ambient Temperature under Bias
Junction Temperature under Bias
V
CC
Pin Potential to Ground Pin
Input Voltage (Note 2)
Input Current (Note 2)
Voltage Applied to Output
in HIGH State (with V
CC
=
0V)
Standard Output
3-STATE Output
Current Applied to Output
in LOW State (Max)
twice the rated I
OL
(mA)
−
65
°
C to
+
150
°
C
−
55
°
C to
+
125
°
C
−
55
°
C to
+
150
°
C
−
0.5V to
+
7.0V
−
0.5V to
+
7.0V
−
30 mA to
+
5.0 mA
Recommended Operating
Conditions
Free Air Ambient Temperature
Supply Voltage
0
°
C to
+
70
°
C
+
4.5V to
+
5.5V
−
0.5V to V
CC
−
0.5V to
+
5.5V
Note 1:
Absolute maximum ratings are values beyond which the device
may be damaged or have its useful life impaired. Functional operation
under these conditions is not implied.
Note 2:
Either voltage limit or current limit is sufficient to protect inputs.
DC Electrical Characteristics
Symbol
V
IH
V
IL
V
CD
V
OH
Parameter
Input HIGH Voltage
Input LOW Voltage
Input Clamp Diode Voltage
Output HIGH
Voltage
10% V
CC
10% V
CC
5% V
CC
5% V
CC
V
OL
I
IH
I
BVI
I
CEX
V
ID
I
OD
I
IL
I
OZH
I
OZL
I
OS
I
ZZ
I
CCH
I
CCL
I
CCZ
Output LOW
Voltage
Input HIGH Current
Input HIGH Current
Breakdown Test
Output HIGH
Leakage Current
Input Leakage
Test
Output Leakage
Circuit Current
Input LOW Current
Output Leakage Current
Output Leakage Current
Output Short-Circuit Current
Bus Drainage Test
Power Supply Current
Power Supply Current
Power Supply Current
31
37
37
−60
4.75
3.75
−0.6
50
−50
−150
500
45
56
56
10% V
CC
2.5
2.4
2.7
2.7
0.5
5.0
7.0
50
V
µA
µA
µA
V
µA
mA
µA
µA
mA
µA
mA
mA
mA
Min
Max
Max
Max
0.0
0.0
Max
Max
Max
Max
0.0V
Max
Max
Max
V
Min
Min
2.0
0.8
−1.2
Typ
Max
Units
V
V
V
Min
V
CC
Conditions
Recognized as a HIGH Signal
Recognized as a LOW Signal
I
IN
= −18
mA
I
OH
= −1
mA
I
OH
= −3
mA
I
OH
= −1
mA
I
OH
= −3
mA
I
OL
=
20 mA
V
IN
=
2.7V
V
IN
=
7.0V
V
OUT
=
V
CC
I
ID
=
1.9
µA
All Other Pins Grounded
V
IOD
=
150 mV
All Other Pins Grounded
V
IN
=
0.5V
V
OUT
=
2.7V
V
OUT
=
0.5V
V
OUT
=
0V
V
OUT
=
5.25V
V
O
=
HIGH
V
O
=
LOW
V
O
=
HIGH Z
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4
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