The IDT54/74FCT521T/AT/BT/CT are 8-bit identity comparators built using an advanced dual metal CMOS technology. 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.
PIN CONFIGURATIONSFUNCTIONAL BLOCK DIAGRAM
A0
B0
A1
B1
A2
B2
A3
B3
A4
B4
A5
B5
A6
B6
A7
B7
IA=B
OA=B
2572 drw 01
&
A0
L20-2
1
20
19
18
17
16
15
14
13
12
IA=B
VCC
IA=B
A0
B0
A1
B1
A2
B2
A3
B3
GND
DIP/SOIC/SSOP/QSOP/CERPACK
INDEX
A1
B1
A2
B2
A3
2
3
P20-1
4
D20-1
SO20-2
5
SO20-7
6
SO20-8
7
8
E20-1
9
1011
TOP VIEW
B0
3 220 19
4
5
6
7
8
9 10111213
OA=B
18
17
16
15
14
VCC1
OA=B
B
7
A7
B6
A6
B5
A5
B4
A4
2572 drw 02
B7
A7
B6
A6
B5
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
4
B3
A
GND
LCC
TOP VIEW
A5
B4
2572 drw 03
MILITARY AND COMMERCIAL TEMPERATURE RANGESAPRIL 1995
IDT54/74FCT521T/AT/BT/CT
FAST CMOS 8-BIT IDENTITY COMPARATOR
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN DESCRIPTION
Pin NamesDescription
A0 - A
7
B0 - B
7
IA =
B
OA =
B
FUNCTION TABLE
Word A Inputs
Word B Inputs
Expansion or Enable Input (Active LOW)
Identity Output (Active LOW)
(1)
2572 tbl 01
InputsOutput
I
A=BA, B
I
L
L
H
H
NOTE:2572 tbl 02
1. H = HIGH Voltage Level
L = LOW Voltage Level
A0 = B0, A1 = B1, A2 = B2, etc.
*
A = B*
A ≠ B
A = B*
A ≠ B
O
A=B
O
L
H
H
H
CAPACITANCE (TA = +25°C, f = 1.0MHz)
SymbolParameter
CINInput
Capacitance
COUTOutput
Capacitance
NOTE:
1. This parameter is measured at characterization but not tested.
(1)
ConditionsTyp.Max. Unit
VIN = 0V610pF
VOUT = 0V812pF
2572 lnk 04
ABSOLUTE MAXIMUM RATINGS
(1)
SymbolRatingCommercialMilitaryUnit
(2)
VTERM
Terminal Voltage
–0.5 to +7.0–0.5 to +7.0V
with Respect to
GND
(3)
VTERM
TAOperating
Terminal Voltage
with Respect to
GND
–0.5 to
CC +0.5
V
–0.5 to
VCC +0.5
0 to +70–55 to +125°C
V
Temperature
TBIASTemperature
–55 to +125–65 to +135°C
Under Bias
TSTGStorage
–55 to +125–65 to +150°C
Temperature
PTPower Dissipation0.50.5W
IOUTDC Output
–60 to +120 –60 to +120 mA
Current
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
V
CC by +0.5V unless otherwise noted.
2. Input and V
3. Outputs and I/O terminals only.
CC terminals only.
2572 lnk 03
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Commercial: TA = 0°C to +70°C, VCC = 5.0V ± 5%; Military: TA = –55°C to +125°C, VCC = 5.0V ± 10%
SymbolParameterTest Conditions
V
IH
V
IL
I
I H
I
I L
I
I
V
IK
I
OS
V
OH
V
OL
V
H
I
CC
NOTES:2572 tbl 05
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
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
Input HIGH LevelGuaranteed Logic HIGH Level2.0——V
Input LOW LevelGuaranteed Logic LOW Level——0.8V
(4)
(4)
(4)
VCC = Max.VI = 2.7V——
VCC = Max.VI = 0.5V——
VCC = Max., VI = V
CC
(Max.)——
Input HIGH Current
Input LOW Current
Input HIGH Current
Clamp Diode VoltageVCC = Min., IN = –18mA—–0.7–1.2V
Short Circuit CurrentVCC = Max.
(3)
, VO = GND–60–120–225mA
Output HIGH VoltageVCC = Min.
V
IN
= V
IH
or V
IL
Output LOW VoltageVCC = Min.
V
IN
= V
IH
or V
IL
Input Hysteresis
—
Quiescent Power Supply CurrentVCC = Max.
V
IN
= GND or V
CC = 5.0V, +25°C ambient.
A = -55°C.
CC
(1)
IOH = –6mA MIL.
I
OH
= –8mA COM'L.
IOH = –12mA MIL.
I
OH
= –15mA COM'L.
IOL = 32mA MIL.
I
OL
= 48mA COM'L.
Min.Typ.
2.43.3—V
2.03.0—V
—0.30.5V
—200—mV
—0.011mA
(2)
Max.Unit
±
±
±
1
µ
A
1
µ
A
1
µ
A
6.162
IDT54/74FCT521T/AT/BT/CT
FAST CMOS 8-BIT IDENTITY COMPARATORMILITARY AND COMMERCIAL TEMPERATURE RANGES
POWER SUPPLY CHARACTERISTICS
SymbolParameterTest Conditions
∆ICC
Quiescent Power Supply
Current TTL
CC = Max.
V
IN = 3.4V
V
(3)
(1)
Min.Typ.
—0.52.0mA
Inputs HIGH
ICCDDynamic Power Supply Current
(4)
VCC = Max.
Outputs Open
IN = VCC
V
IN = GND
V
—0.150.25mA/
One Input Toggling
50% Duty Cycle
ICTotal Power Supply Current
(5)
VCC = Max.
Outputs Open
fi = 10MHz
One Bit Toggling
VIN = VCC
IN = GND
V
IN = 3.4V
V
IN = GND
V
—1.53.5mA
—1.84.5
50% Duty Cycle
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
3. Per TTL driven input (V
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
C = IQUIESCENT + IINPUTS + IDYNAMIC
6. I
IC = ICC + ∆ICC DHNT + ICCD (fCP/2 + fiNi)
I
CC = Quiescent Current
CC = Power Supply Current for a TTL High Input (VIN = 3.4V)
∆I
H = Duty Cycle for TTL Inputs High
D
T = Number of TTL Inputs at DH
N
ICCD = Dynamic Current Caused by an Input Transition Pair (HLH or LHL)
CP = Clock Frequency for Register Devices (Zero for Non-Register Devices)
f
i = Input Frequency
f
i = Number of Inputs at fi
N
All currents are in milliamps and all frequencies are in megahertz.
CC = 5.0V, +25°C ambient.
IN = 3.4V). All other inputs at VCC or GND.
CC formula. These limits are guaranteed but not tested.