FAST CMOS 8-BIT
IDENTITY COMPARATOR
Integrated Device Technology, Inc.
IDT54/74FCT521T
IDT54/74FCT521AT
IDT54/74FCT521BT
IDT54/74FCT521CT
FEATURES:
•
•
•
•
Std., A, B and C speed 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
Product available in Radiation Tolerant and Radiation
Enhanced versions
Military product compliant to MIL-STD-883, Class B
and DESC listed (dual marked)
Available in DIP, SOIC, SSOP, QSOP, CERPACK and
LCC packages
DESCRIPTION:
The IDT54/74FCT521T/AT/BT/CT are 8-bit identity com-
parators built using an advanced dual metal CMOS technol-
ogy. These devices compare two words of up to eight bits each
and provide a LOW output when the two words match bit for
bit. The expansion input
I
A
=
B
also serves as an active LOW
enable input.
•
•
•
•
•
FUNCTIONAL BLOCK DIAGRAM
PIN CONFIGURATIONS
I
A=B
1
2
3
4
5
6
7
8
9
10
20
19
P20-1
D20-1
SO20-2
SO20-7
SO20-8
&
E20-1
18
17
16
15
14
13
12
11
V
CC
O
A=B
B
7
A
7
B
6
A
6
B
5
A
5
B
4
A
4
2572 drw 02
A
0
B
0
A
1
B
1
A
2
B
2
A
3
B
3
A
4
B
4
A
5
B
5
A
6
B
6
A
7
B
7
I
A=B
2572 drw 01
A
0
B
0
A
1
B
1
A
2
B
2
A
3
B
3
GND
O
A=B
DIP/SOIC/SSOP/QSOP/CERPACK
TOP VIEW
3 2
A
1
B
1
A
2
B
2
A
3
4
5
6
7
8
I
A=B
V
CC
B
0
A
0
INDEX
1
20 19
18
17
16
15
14
O
A=B
B
7
A
7
B
6
A
6
B
5
L20-2
9 10 11 12 13
B
3
GND
A
4
B
4
A
5
2572 drw 03
LCC
TOP VIEW
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
©1995
Integrated Device Technology, Inc.
APRIL 1995
DSC-4210/4
6.16
1
IDT54/74FCT521T/AT/BT/CT
FAST CMOS 8-BIT IDENTITY COMPARATOR
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN DESCRIPTION
Pin Names
A
0
- A
7
B
0
- B
7
I
A
O
A
ABSOLUTE MAXIMUM RATINGS
(1)
Description
Word A Inputs
Word B Inputs
Expansion or Enable Input (Active LOW)
Identity Output (Active LOW)
2572 tbl 01
=
B
=
B
FUNCTION TABLE
Inputs
I
A=B
(1)
Output
A, B
A = B*
A
≠
B
A = B*
A
≠
B
O
A=B
L
L
H
H
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
*
A
0 =
B
0,
A
1 =
B
1,
A
2 =
B
2, etc.
L
H
H
H
2572 tbl 02
Symbol
Rating
Commercial
V
TERM(2)
Terminal Voltage
–0.5 to +7.0
with Respect to
GND
V
TERM(3)
Terminal Voltage
–0.5 to
with Respect to
V
CC
+0.5
GND
T
A
Operating
0 to +70
Temperature
T
BIAS
Temperature
–55 to +125
Under Bias
T
STG
Storage
–55 to +125
Temperature
P
T
Power Dissipation
0.5
I
OUT
DC Output
Current
–60 to +120
Military
–0.5 to +7.0
Unit
V
–0.5 to
V
CC
+0.5
–55 to +125
–65 to +135
–65 to +150
0.5
–60 to +120
V
°C
°C
°C
W
mA
CAPACITANCE
(T
A
= +25°C, f = 1.0MHz)
Symbol
Parameter
(1)
C
IN
Input
Capacitance
C
OUT
Output
Capacitance
Conditions
V
IN
= 0V
V
OUT
= 0V
Typ.
6
8
Max. Unit
10
pF
12
pF
2572 lnk 03
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RAT-
INGS 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. Input and V
CC
terminals only.
3. Outputs and I/O terminals only.
2572 lnk 04
NOTE:
1. This parameter is measured at characterization but not tested.
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
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
I H
I
I L
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
= Min., I
N
= –18mA
V
CC
= Max.
(3)
, V
O
= GND
V
CC
= Min.
V
IN
= V
IH
or V
IL
I
OH
= –6mA MIL.
I
OH
= –8mA COM'L.
I
OH
= –12mA MIL.
I
OH
= –15mA COM'L.
I
OL
= 32mA MIL.
I
OL
= 48mA COM'L.
—
Min.
2.0
—
—
—
—
—
–60
2.4
2.0
—
—
—
Typ.
(2)
—
—
—
—
—
–0.7
–120
3.3
3.0
0.3
200
0.01
Max.
—
0.8
Unit
V
V
V
I
= 2.7V
V
I
= 0.5V
±
1
±
1
±
1
–1.2
–225
—
—
0.5
—
1
µ
A
µ
A
µ
A
V
mA
V
V
V
mV
mA
2572 tbl 05
V
CC
= Max., V
I
= V
CC
(Max.)
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
V
CC
= Max.
V
IN
= GND or V
CC
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. Not more than one output should be shorted at one time. Duration of the short circuit test should not exceed one second.
4. The test limit for this parameter is
±5µA
at T
A
= -55°C.
6.16
2
IDT54/74FCT521T/AT/BT/CT
FAST CMOS 8-BIT IDENTITY COMPARATOR
MILITARY AND COMMERCIAL TEMPERATURE RANGES
POWER SUPPLY CHARACTERISTICS
Symbol
∆I
CC
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
fi = 10MHz
One Bit Toggling
50% Duty Cycle
V
IN
= V
CC
V
IN
= GND
Test Conditions
(1)
Min.
—
Typ.
(2)
0.5
Max.
2.0
Unit
mA
I
CCD
—
0.15
0.25
mA/
MHz
I
C
Total Power Supply Current
(5)
V
IN
V
IN
V
IN
V
IN
= V
CC
= GND
= 3.4V
= GND
—
—
1.5
1.8
3.5
4.5
mA
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. Values for these conditions are examples of the I
CC
formula. These limits are guaranteed but not tested.
6. I
C
= I
QUIESCENT
+ I
INPUTS
+ I
DYNAMIC
I
C
= I
CC
+
∆I
CC
D
H
N
T
+ I
CCD
(f
CP/
2 + f
i
N
i
)
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
CP
= Clock Frequency for Register Devices (Zero for Non-Register Devices)
f
i
= Input Frequency
N
i
= Number of Inputs at f
i
All currents are in milliamps and all frequencies are in megahertz.
2572 tbl 06
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
IDT54/74FCT521T
IDT54/74FCT521AT
IDT54/74FCT521BT
IDT54/74FCT521CT
Com'l.
Symbol
t
PLH
t
PHL
Parameter
Propagation
Delay
An or Bn to
O
A
=
B
Propagation
Delay
I
A
=
B
to
O
A
=
B
Condition
(1)
CL = 50pF
RL = 500
Ω
Mil.
Com'l.
Mil.
Com'l.
Mil.
Com'l.
Mil.
Unit
ns
Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max.
1.5 11.0 1.5 15.0 1.5
7.2
1.5
9.5
1.5
5.5
1.5
7.3
1.5
4.5
1.5
5.1
t
PLH
t
PHL
1.5 10.0 1.5
9.0
1.5
6.0
1.5
7.8
1.5
4.6
1.5
6.0
1.5
4.1
1.5
4.5
ns
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
2572 tbl 07
6.16
3
IDT54/74FCT521T/AT/BT/CT
FAST CMOS 8-BIT IDENTITY COMPARATOR
MILITARY AND COMMERCIAL TEMPERATURE RANGES
TEST CIRCUITS AND WAVEFORMS
TEST CIRCUITS FOR ALL OUTPUTS
V
CC
500
Ω
V
IN
Pulse
Generator
R
T
D.U.T.
50pF
C
L
2572 drw 04
SWITCH POSITION
Test
7.0V
Switch
Open Drain
Disable Low
Enable Low
All Other Tests
Closed
Open
V
OUT
500
Ω
2572 lnk 08
DEFINITIONS:
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
PULSE WIDTH
DATA
INPUT
TIMING
INPUT
ASYNCHRONOUS CONTROL
PRESET
CLEAR
ETC.
SYNCHRONOUS CONTROL
PRESET
CLEAR
CLOCK ENABLE
ETC.
t
SU
t
H
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
2572 drw 05
LOW-HIGH-LOW
PULSE
t
W
HIGH-LOW-HIGH
PULSE
1.5V
t
REM
1.5V
2572 drw 06
t
SU
t
H
PROPAGATION DELAY
3V
1.5V
0V
V
OH
1.5V
V
OL
3V
1.5V
0V
2572 drw 07
ENABLE AND DISABLE TIMES
ENABLE
DISABLE
3V
CONTROL
INPUT
t
PZL
OUTPUT
NORMALLY
LOW
OUTPUT
NORMALLY
HIGH
SWITCH
CLOSED
t
PZH
SWITCH
OPEN
1.5V
0V
3.5V
1.5V
t
PHZ
0.3V
V
OH
0V
2572 drw 08
SAME PHASE
INPUT TRANSITION
t
PLH
OUTPUT
t
PLH
OPPOSITE PHASE
INPUT TRANSITION
t
PHL
t
PHL
1.5V
t
PLZ
0V
3.5V
0.3V
V
OL
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
6.16
4
IDT54/74FCT521T/AT/BT/CT
FAST CMOS 8-BIT IDENTITY COMPARATOR
MILITARY AND COMMERCIAL TEMPERATURE RANGES
ORDERING INFORMATION
IDT
XX
Temp. Range
FCT
X
Family
XXXX
Device Type
X
Package
X
Process
Blank
B
P
D
E
L
SO
P
Q
521T
521AT
521BT
521CT
Blank
54
74
Commercial
MIL-STD-883, Class B
Plastic DIP
CERDIP
CERPACK
Leadless Chip Carrier
Small Outline IC
Shrink Small Outline Package
Quarter-size Small Outline Package
8-Bit Comparator
High Drive
–55°C to +125°C
0°C to +70°C
2572 drw 09
6.16
5
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