®
FAST CMOS
1-OF-8 DECODER
WITH ENABLE
DESCRIPTION:
IDT54/74FCT138
IDT54/74FCT138A
IDT54/74FCT138C
Integrated Device Technology, Inc.
FEATURES:
•
•
•
•
•
•
•
•
•
•
•
•
•
IDT54/74FCT138 equivalent to FAST™ speed
IDT54/74FCT138A 35% faster than FAST
IDT54/74FCT138C 40% faster than FAST
Equivalent to FAST speeds output drive over full tem-
perature and voltage supply extremes
I
OL
= 48mA (commercial) and 32mA (military)
CMOS power levels (1mW typ. static)
TTL input and output level compatible
CMOS output level compatible
Substantially lower input current levels than FAST
(5µA max.)
JEDEC standard pinout for DIP and LCC
Product available in Radiation Tolerant and Radiation
Enhanced versions
Military product compliant to MIL-STD-883, Class B
Standard Military Drawing # 5962-87654 is listed on this
function. Refer to section 2.
The IDT54/74FCT138/A/C are 1-of-8 decoders built using
an advanced dual metal CMOS technology. The IDT54/
74FCT138/A/C accept three binary weighted inputs (A
0
, A
1
,
A
2
) and, when enabled, provide eight mutually exclusive
active LOW outputs (
O
0
-
O
7
). The IDT54/74FCT138/A/C
feature 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 IDT54/74FCT138/A/C devices
and one inverter.
FUNCTIONAL BLOCK DIAGRAM
A
2
A
1
A
0
E
1
E
2
E
3
PIN CONFIGURATIONS
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
P16-1,
D16-1,
SO16-1
&
E16-1
14
13
12
11
10
9
Vcc
O
0
O
1
O
2
O
3
O
4
O
5
O
6
DIP/SOIC/CERPACK
TOP VIEW
INDEX
O
7
O
6
O
5
O
4
O
3
O
2
O
1
O
0
2581 drw 02
A
2
E
1
NC
E
2
E
3
A
1
A
0
NC
Vcc
O
0
3
4
5
6
7
8
2
20 19
18
1
17
16
15
14
9 10 11 12 13
L20-2
O
1
O
2
NC
O
3
O
4
2581 drw 01
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
FAST is a trademark of National Semiconductor Co.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
©1992
Integrated Device Technology, Inc.
O
7
GND
NC
O
6
O
5
LCC
TOP VIEW
MAY 1992
DSC-4625/3
7.3
1
IDT54/74FCT138/A/C
FAST CMOS 1-OF-8 DECODER-WITH ENABLE
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN DESCRIPTION
Pin Names
A
0
–A
2
Address Inputs
Enable Inputs (Active LOW)
Enable Input (Active HIGH)
Outputs (Active LOW)
2581 tbl 05
Description
E
1
,
E
2
E
3
O
0
–
O
7
FUNCTION TABLE
Inputs
Outputs
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
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
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
O
3
H
H
H
H
H
H
L
H
H
H
H
O
4
H
H
H
H
H
H
H
L
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
2581 tbl 06
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
Rating
(2)
V
TERM
Terminal Voltage
with Respect
to GND
(3)
V
TERM
Terminal Voltage
with Respect
to GND
T
A
Operating
Temperature
T
BIAS
Temperature
Under Bias
T
STG
Storage
Temperature
P
T
Power Dissipation
DC Output Current
I
OUT
Commercial
Military
Unit
–0.5 to +7.0 –0.5 to +7.0
V
CAPACITANCE
(T
A
= +25°C, f = 1.0MHz)
Symbol
C
IN
C
OUT
Parameter
(1)
Input Capacitance
Conditions
V
IN
= 0V
Typ. Max. Unit
6
8
10
12
pF
pF
02
Output Capacitance V
OUT
= 0V
–0.5 to V
CC
–0.5 to V
CC
V
NOTE:
2581 tbl
1. This parameter is guaranteed characterization data and not tested.
0 to +70
–55 to +125
–55 to +125
0.5
120
–55 to +125
–65 to +135
–65 to +150
0.5
120
°C
°C
°C
W
mA
NOTES:
2581 tbl 01
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 V
CC
by +0.5V unless otherwise noted.
2. Inputs and V
CC
terminals only.
3. Outputs and I/O terminals only.
7.3
2
IDT54/74FCT138/A/C
FAST CMOS 1-OF-8 DECODER-WITH ENABLE
MILITARY AND COMMERCIAL TEMPERATURE RANGES
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified: V
LC
= 0.2V; V
HC
= V
CC
– 0.2V
Commercial: T
A
= 0°C to +70°C, V
CC
= 5.0V
±
5%; Military: T
A
= –55°C to +125°C, V
CC
= 5.0V
±
10%
Symbol
V
IH
V
IL
I
IH
I
IL
V
IK
I
OS
V
OH
Parameter
Input HIGH Level
Input LOW Level
Input HIGH Current
Input LOW Current
Clamp Diode Voltage
Short Circuit Current
Output HIGH Voltage
Test Conditions
(1)
Guaranteed Logic HIGH Level
Guaranteed Logic LOW Level
V
CC
= Max.
V
I
= V
CC
V
I
= 2.7V
V
I
= 0.5V
V
I
= GND
V
CC
= Min., I
N
= –18mA
V
CC
= Max.
(3)
, V
O
= GND
V
CC
= 3V, V
IN
= V
LC
or V
HC
, I
OH
= –32µA
I
OH
= –300µA
V
CC
= Min.
I
OH
= –12mA MIL.
V
IN
= V
IH
or V
IL
I
OH
= –15mA COM’L.
V
CC
= 3V, V
IN
= V
LC
or V
HC
, I
OL
= 300µA
I
OL
= 300µA
V
CC
= Min.
V
IN
= V
IH
or V
IL
I
OL
= 32mA MIL.
I
OL
= 48mA COM’L.
Min.
2.0
—
—
—
—
—
—
–60
V
HC
V
HC
2.4
2.4
—
—
—
—
Typ.
(2)
—
—
—
—
—
—
–0.7
–120
V
CC
V
CC
4.3
4.3
GND
GND
0.3
0.3
Max.
—
0.8
5
5
(4)
–5
(4)
–5
–1.2
—
—
—
—
—
V
LC
V
LC(4)
0.5
0.5
Unit
V
V
µA
V
mA
V
V
OL
Output LOW Voltage
V
NOTES:
1. For conditions shown as Max. or Min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25°C ambient and maximum loading.
3. Not more than one output should be shorted at one time. Duration of the short circuit test should not exceed one second.
4. This parameter is guaranteed but not tested.
2581 tbl 03
POWER SUPPLY CHARACTERISTICS
V
LC
= 0.2V; V
HC
= V
CC
– 0.2V
Symbol
I
CC
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
Quiescent Power Supply Current
TTL Inputs HIGH
Dynamic Power Supply Current
(4)
Test Conditions
(1)
Vcc = Max.
V
IN
≥
V
HC
; V
IN
≤
V
LC
Vcc = Max.
V
IN
= 3.4V
(3)
Vcc = Max.
Outputs Open
One Output Toggling
50% Duty Cycle
Vcc = Max.
Outputs Open
Toggle
E
1
,
E
2
or E
3
50% Duty Cycle
f
O
= 10MHz
One Output Toggling
V
IN
≥
V
HC
V
IN
≤
V
LC
Min.
—
—
—
Typ.
(2)
0.2
0.5
0.15
Max.
1.5
2.0
0.3
Unit
mA
mA
mA/MHz
I
C
Total Power Supply Current
(5)
V
IN
≥
V
HC
V
IN
≤
V
LC
(FCT)
V
IN
= 3.4V
V
IN
= GND
—
1.7
4.5
mA
—
2.0
5.5
NOTES:
1. For conditions shown as Max. or Min., 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
CP
/2 + 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 Output Transition Pair (HLH or LHL)
f
CP
= Clock Frequency for Register Devices (Zero for Non-Register Devices)
f
O
= Output Frequency
N
O
= Number of Outputs at f
O
All currents are in milliamps and all frequencies are in megahertz.
2581 tbl 04
7.3
3
IDT54/74FCT138/A/C
FAST CMOS 1-OF-8 DECODER-WITH ENABLE
MILITARY AND COMMERCIAL TEMPERATURE RANGES
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
IDT54/74FCT138
Com’l.
Symbol
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
Parameter
Propagation Delay
A
n
to
O
n
Propagation Delay
E
1
or
E
2
to
O
n
Propagation Delay
E
3
to
O
n
Condition
(1)
IDT54/74FCT138A
Com’l.
(2)
IDT54/74FCT138C
Com’l.
Min.
(2)
Mil.
(2)
Mil.
(2)
Mil.
(2)
Min.
(2)
Max. Min.
Max. Min.
Max. Min.
Max.
Max. Min
.
Max.
Unit
C
L
= 50pF
R
L
= 500Ω
1.5
1.5
1.5
9.0
9.0
9.0
1.5
1.5
1.5
12.0
12.5
12.5
1.5
1.5
1.5
5.8
5.9
5.9
1.5
1.5
1.5
7.8
8.0
8.0
1.5
1.5
1.5
5.1
5.2
5.2
1.5
1.5
1.5
6.0
6.1
6.1
ns
ns
ns
2581 tbl 07
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
7.3
4
IDT54/74FCT138/A/C
FAST CMOS 1-OF-8 DECODER-WITH ENABLE
MILITARY AND COMMERCIAL TEMPERATURE RANGES
TEST CIRCUITS AND WAVEFORMS
TEST CIRCUITS FOR ALL OUTPUTS
V
CC
500Ω
V
IN
Pulse
Generator
R
T
D.U.T.
50pF
C
L
500Ω
V
OUT
7.0V
SWITCH POSITION
Test
Open Drain
Disable Low
Enable Low
All Other Test
Switch
Closed
Open
DEFINITIONS:
2581 tbl 08
C
L
= Load capacitance: includes jig and probe capacitance.
R
T
= Termination resistance: should be equal to Z
OUT
of the Pulse
Generator.
SET-UP, HOLD AND RELEASE TIMES
DATA
INPUT
t
SU
TIMING
INPUT
ASYNCHRONOUS CONTROL
PRESET
CLEAR
ETC.
SYNCHRONOUS CONTROL
PRESET
CLEAR
CLOCK ENABLE
ETC.
t
REM
3V
1.5V
0V
3V
1.5V
0V
t
H
3V
1.5V
0V
3V
1.5V
0V
PULSE WIDTH
LOW-HIGH-LOW
PULSE
t
W
HIGH-LOW-HIGH
PULSE
1.5V
1.5V
t
SU
t
H
PROPAGATION DELAY
3V
1.5V
t
PLH
OUTPUT
t
PLH
OPPOSITE PHASE
INPUT TRANSITION
t
PHL
3V
1.5V
0V
t
PHL
0V
V
OH
1.5V
V
OL
ENABLE AND DISABLE TIMES
ENABLE
CONTROL
INPUT
t
PZL
OUTPUT
NORMALLY SWITCH
LOW CLOSED
t
PZH
OUTPUT SWITCH
NORMALLY OPEN
HIGH
3.5V
1.5V
0.3V
t
PHZ
0.3V
1.5V
0V
V
OH
0V
t
PLZ
DISABLE
3V
1.5V
0V
3.5V
V
OL
SAME PHASE
INPUT TRANSITION
NOTES
2581 drw 04
1. Diagram shown for input Control Enable-LOW and input Control
Disable-HIGH.
2. Pulse Generator for All Pulses: Rate
≤
1.0 MHz; Z
O
≤
50Ω; t
F
≤
2.5ns;
t
R
≤
2.5ns.
7.3
5
Microchip MCU
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
