IDT54/74FCT138T/AT/CT
FAST CMOS 1-OF-8 DECODER WITH ENABLE
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
FAST CMOS
1-OF-8 DECODER
WITH ENABLE
FEATURES:
•
•
•
•
IDT54/74FCT138T/AT/CT
•
•
•
•
•
Std., A, and C grades
Low input and output leakage
≤
1µA (max.)
CMOS power levels
True TTL input and output compatibility:
– V
OH
= 3.3V (typ.)
– V
OL
= 0.3V (typ.)
High Drive outputs (-15mA I
OH
, 48mA I
OL
)
Meets or exceeds JEDEC standard 18 specifications
Military product compliant to MIL-STD-883, Class B and DESC
listed (dual marked)
Power off disable outputs permit "live insertion"
Available in the following packages:
– Industrial: SOIC, QSOP
– Military: CERDIP, LCC
The IDT54/74FCT138T is a 1-of-8 decoder built using an advanced
dual metal CMOS technology. The IDT54/74FCT138T accepts three
binary weighted inputs (A
0
, A
1
, A
2
) and, when enabled, provides eight
mutually exclusive active low outputs (O
0
-
O
7
). The IDT54/74FCT138T
features three enable inputs, two active low (E
1
,
E
2
) and one active high
(E
3
). All outputs will be high unless
E
1
and
E
2
are low and E
3
is high. This
multiple enable function allows easy parallel expansion of the device to a
1-of-32 (5 lines to 32 lines) decoder with just four IDT54/74FCT138T
devices and one inverter.
DESCRIPTION:
FUNCTIONAL BLOCK DIAGRAM
A
2
A
1
A
0
E
1
E
2
E
3
O
7
O
6
O
5
O
4
O
3
O
2
O
1
O
0
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
1
JUNE 2002
DSC-2570/9
© 2002 Integrated Device Technology, Inc.
IDT54/74FCT138T/AT/CT
FAST CMOS 1-OF-8 DECODER WITH ENABLE
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
PIN CONFIGURATION
NC
A
1
A
0
A
0
A
1
A
2
E
1
E
2
E
3
O
7
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
O
0
O
1
O
2
O
3
O
4
O
5
O
6
A
2
E
1
NC
E
2
E
3
4
5
6
7
8
3
2
1
20
19
18
17
16
15
14
O
0
INDEX
V
CC
O
1
O
2
NC
O
3
O
4
9
10
11
12
13
O
6
CERDIP/ SOIC/ QSOP
TOP VIEW
LCC
TOP VIEW
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
TERM
(3)
T
STG
I
OUT
Description
Terminal Voltage with Respect to GND
Storage Temperature
DC Output Current
Max
–0.5 to +7
–0.5 to V
CC
+0.5
–65 to +150
–60 to +120
Unit
V
V
°C
mA
V
TERM
(2)
Terminal Voltage with Respect to GND
PIN DESCRIPTION
Pin Names
A
0
- A
2
E
1
,
E
2
E
3
O
0
-
O
7
Address Inputs
Enable Inputs (Active LOW)
Enable Input (Active HIGH)
Outputs (Active LOW)
Description
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability. No terminal voltage may exceed
Vcc by =0.5V unless otherwise noted.
2. Inputs and Vcc terminals only.
3. Output and I/O terminals only.
CAPACITANCE
(T
A
= +25°C, F = 1.0MHz)
Symbol
C
IN
C
OUT
Parameter
(1)
Input Capacitance
Output Capacitance
Conditions
V
IN
= 0V
V
OUT
= 0V
Typ.
6
8
Max.
10
12
Unit
pF
pF
NOTE:
1. This parameter is measured at characterization but not tested.
2
GND
NC
O
7
O
5
IDT54/74FCT138T/AT/CT
FAST CMOS 1-OF-8 DECODER WITH ENABLE
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
FUNCTION TABLE
(1)
Inputs
E
1
H
X
X
L
L
L
L
L
L
L
L
E
2
X
H
X
L
L
L
L
L
L
L
L
E
3
X
X
L
H
H
H
H
H
H
H
H
A
0
X
X
X
L
H
L
H
L
H
L
H
A
1
X
X
X
L
L
H
H
L
L
H
H
A
2
X
X
X
L
L
L
L
H
H
H
H
O
0
H
H
H
L
H
H
H
H
H
H
H
O
1
H
H
H
H
L
H
H
H
H
H
H
O
2
H
H
H
H
H
L
H
H
H
H
H
Outputs
O
3
O
4
H
H
H
H
H
H
H
H
H
H
H
H
L
H
H
L
H
H
H
H
H
H
O
5
H
H
H
H
H
H
H
H
L
H
H
O
6
H
H
H
H
H
H
H
H
H
L
H
O
7
H
H
H
H
H
H
H
H
H
H
L
NOTE:
1. H = HIGH Voltage Level
X = Don’t Care
L = LOW Voltage Level
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= –40°C to +85°C, V
CC
= 5.0V ±10%; Military: T
A
= –55°C to +125°C, V
CC
= 5.0V ±10%
Symbol
V
IH
V
IL
I
IH
I
IL
I
I
V
IK
I
OS
V
OH
Parameter
Input HIGH Level
Input LOW Level
Input HIGH Current
(4)
Input LOW Current
(4)
Input HIGH Current
(4)
Clamp Diode Voltage
Short Circuit Current
Output HIGH Voltage
Test Conditions
(1)
Guaranteed Logic HIGH Level
Guaranteed Logic LOW Level
V
CC
= Max.
V
CC
= Max.
V
CC
= Max., V
I
= V
CC
(Max.)
V
CC
= Min., I
IN
= –18mA
V
CC
= Max., V
O
= GND
(3)
V
CC
= Min
V
IN
= V
IH
or V
IL
I
OH
= –6mA MIL
I
OH
= –8mA IND
I
OH
= –12mA MIL
I
OH
= –15mA IND
I
OL
= –32mA MIL
I
OL
= –48mA IND
—
V
CC
= Max.
V
IN
= GND or V
CC
V
I
= 2.7V
V
I
= 0.5V
Min.
2
—
—
—
—
—
–60
2.4
2
—
—
—
Typ.
(2)
—
—
—
—
—
–0.7
–120
3.3
3
0.3
200
0.01
Max.
—
0.8
±1
±1
±1
–1.2
–225
—
—
0.5
—
1
V
mV
µA
µA
V
mA
V
Unit
V
V
µA
V
OL
V
H
I
CC
Output LOW Voltage
Input Hysteresis
Quiescent Power Supply Current
V
CC
= Min
V
IN
= V
IH
or V
IL
NOTES:
1. For conditions shown as Min. or Max., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25°C ambient.
3. Not more than one output should be tested at one time. Duration of the test should not exceed one second.
4. The test limit for this parameter is ±5µA at T
A
= –55°C.
3
IDT54/74FCT138T/AT/CT
FAST CMOS 1-OF-8 DECODER WITH ENABLE
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
POWER SUPPLY CHARACTERISTICS
Symbol
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
TTL Inputs HIGH
Dynamic Power Supply
Current
(4)
V
CC
= Max.
V
IN
= 3.4V
(3)
V
CC
= Max.
Outputs Open
One Input Toggling
50% Duty Cycle
V
CC
= Max.
Outputs Open
Toggle
E
1
,
E
2
, or E
3
50% Duty Cycle
fo = 10MHz
One Input and
One Output Toggling
NOTES:
1. For conditions shown as Min. or Max., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25°C ambient.
3. Per TTL driven input; (V
IN
= 3.4V). All other inputs at V
CC
or GND.
4. This parameter is not directly testable, but is derived for use in Total Power Supply Calculations.
5. I
C
= I
QUIESCENT
+ I
INPUTS
+ I
DYNAMIC
I
C
= I
CC
+
∆I
CC
D
H
N
T
+ I
CCD
(f
O
N
O
)
I
CC
= Quiescent Current
∆I
CC
= Power Supply Current for a TTL High Input (V
IN
= 3.4V)
D
H
= Duty Cycle for TTL Inputs High
N
T
= Number of TTL Inputs at D
H
I
CCD
= Dynamic Current caused by an Input Transition Pair (HLH or LHL)
f
O
= Output Frequency
N
O
= Number of Outputs at f
O
All currents are in milliamps and all frequencies are in megahertz.
Test Conditions
(1)
Min.
—
Typ.
(2)
0.5
0.15
Max.
2
0.3
Unit
mA
mA/
MHz
V
IN
= V
CC
V
IN
= GND
—
I
C
Total Power Supply Current
(5)
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4V
V
IN
= GND
—
1.5
4
mA
—
1.8
5
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
Symbol
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
Parameter
Propagation Delay
Ax to
Ox
Propagation Delay
E
1
or
E
2
to
Ox
Propagation Delay
E
3
to
Ox
Condition
(1)
C
L
= 50pF
R
L
= 500Ω
54FCT138T
Mil.
Min.
(2)
Max.
1.5
12
1.5
1.5
12.5
12.5
54/74FCT138AT
Ind.
Mil.
Min.
(2)
Max.
Min.
(2)
Max.
1.5
5.8
1.5
7.8
1.5
1.5
5.9
5.9
1.5
1.5
8
8
54/74FCT138CT
Ind.
Min.
(2)
1.5
1.5
1.5
Max.
5.1
5.2
5.2
Mil.
Min.
(2)
1.5
1.5
1.5
Max.
6
6.1
6.1
Unit
ns
ns
ns
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
4
IDT54/74FCT138T/AT/CT
FAST CMOS 1-OF-8 DECODER WITH ENABLE
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
TEST CIRCUITS AND WAVEFORMS
V
CC
500Ω
V
IN
Pulse
Generator
R
T
D.U.T
.
V
OUT
7.0V
SWITCH POSITION
Test
Open Drain
Disable Low
Enable Low
All Other Tests
Switch
Closed
Open
50pF
C
L
500Ω
DEFINITIONS:
C
L
= Load capacitance: includes jig and probe capacitance.
R
T
= Termination resistance: should be equal to Z
OUT
of the Pulse Generator.
Octal link
Test Circuits for All Outputs
DATA
INPUT
TIMING
INPUT
ASYNCHRONOUS CONTROL
PRESET
CLEAR
ETC.
SYNCHRONOUS CONTROL
PRESET
CLEAR
CLOCK ENABLE
ETC.
t
SU
t
H
t
REM
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
Octal link
LOW-HIGH-LOW
PULSE
t
W
HIGH-LOW-HIGH
PULSE
Octal link
1.5V
1.5V
t
SU
t
H
Pulse Width
Set-Up, Hold, and Release Times
ENABLE
SAME PHASE
INPUT TRANSITION
t
PLH
OUTPUT
t
PLH
OPPOSITE PHASE
INPUT TRANSITION
t
PHL
t
PHL
3V
1.5V
0V
V
OH
1.5V
V
OL
3V
1.5V
0V
Octal link
DISABLE
3V
1.5V
CONTROL
INPUT
t
PZL
OUTPUT
NORMALLY
LOW
OUTPUT
NORMALLY
HIGH
SWITCH
CLOSED
t
PZH
SWITCH
OPEN
3.5V
1.5V
t
PHZ
0.3V
1.5V
0V
t
PLZ
0V
3.5V
0.3V
V
OL
V
OH
0V
Octal link
Propagation Delay
Enable and Disable Times
NOTES:
1. Diagram shown for input Control Enable-LOW and input Control Disable-HIGH.
2. Pulse Generator for All Pulses: Rate
≤
1.0MHz; t
F
≤
2.5ns; t
R
≤
2.5ns.
5
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