Philips Semiconductors
Product specification
8-bit identity comparator
74F521
FEATURES
•
Compares two 8-bit words in 6.5ns typical
•
Expandable to any word length
DESCRIPTION
The 74F521 is an expandable 8-bit comparator. It compares two
words of up to 8 bits each and provides 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.
TYPICAL
PROPAGATION
DELAY
7.0ns
TYPICAL
SUPPLY CURRENT
(TOTAL)
24mA
PIN CONFIGURATION
I
A=B
1
A0
B0
A1
B1
A2
B2
A3
B3
2
3
4
5
6
7
8
9
20 V
CC
19 Q
A=B
18 B7
17 A7
16 B6
15 A6
14 B5
13 A5
12 B4
11 A4
TYPE
74F521
GND 10
SF00273
ORDERING INFORMATION
DESCRIPTION
20-pin plastic DIP
20-pin plastic SOL
COMMERCIAL RANGE
V
CC
= 5V
±10%,
T
amb
= 0°C to +70°C
N74F521N
N74F521D
PKG DWG #
SOT146-1
SOT163-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
A0 – A7
B0 – B7
I
A=B
Q
A=B
Word A inputs
Word B inputs
Expansion or Enable input (active Low)
Identity output (active Low)
DESCRIPTION
74F (U.L.) HIGH/LOW
1.0/1.0
1.0/1.0
1.0/1.0
50/33
LOAD VALUE HIGH/LOW
20µA/0.6mA
20µA/0.6mA
20µA/0.6mA
1.0mA/20mA
NOTE:
One (1.0) FAST unit load is defined as: 20µA in the High state and 0.6mA in the Low state.
LOGIC SYMBOL
1
IEC/IEEE SYMBOL
2
I
A=B
4
6
8
11
13
15
17
Q
A=B
19
3
5
7
9
12
14
15
18
1
7
EN
B
3
A=B
0
19
A
COMP
0
2
3
4
5
6
7
8
9
11
12
13
14
15
16
17
18
V
CC
= Pin 20
GND = Pin 10
A0
B0
A1
B1
A2
B2
A3
B3
A4
B4
A5
B5
A6
B6
A7
B7
SF00274
SF00275
May 15, 1990
2
853–0372 99601
Philips Semiconductors
Product specification
8-bit identity comparator
74F521
ABSOLUTE MAXIMUM RATINGS
(Operation beyond the limits set forth in this table may impair the useful life of the device.
Unless otherwise noted these limits are over the operating free-air temperature range.)
SYMBOL
V
CC
V
IN
I
IN
V
OUT
I
OUT
T
amb
T
stg
Supply voltage
Input voltage
Input current
Voltage applied to output in High output state
Current applied to output in Low output state
Operating free-air temperature range
Storage temperature range
PARAMETER
RATING
–0.5 to +7.0
–0.5 to +7.0
–30 to +5
–0.5 to V
CC
40
0 to +70
–65 to +150
UNIT
V
V
mA
V
mA
°C
°C
RECOMMENDED OPERATING CONDITIONS
LIMITS
SYMBOL
V
CC
V
IH
V
IL
I
IK
I
OH
I
OL
T
amb
Supply voltage
High-level input voltage
Low-level input voltage
Input clamp current
High-level output current
Low-level output current
Operating free-air temperature range
0
PARAMETER
MIN
4.5
2.0
0.8
–18
–1
20
+70
NOM
5.0
MAX
5.5
V
V
V
mA
mA
mA
°C
UNIT
DC ELECTRICAL CHARACTERISTICS
(Over recommended operating free-air temperature range unless otherwise noted.)
SYMBOL
PARAMETER
TEST CONDITIONS
1
V
CC
= MIN, V
IL
= MAX
V
IH
= MIN, I
OH
= MAX
Low-level
Low level output voltage
Input clamp voltage
Input current at maximum input voltage
High-level input current
Low-level input current
Short-circuit output current
3
Supply current (total)
I
CCH
I
CCL
V
CC
= MIN, V
IL
= MAX
V
IH
= MIN, I
OL
= MAX
V
CC
= MIN, I
I
= I
IK
V
CC
= MAX, V
I
= 7.0V
V
CC
= MAX, V
I
= 2.7V
V
CC
= MAX, V
I
= 0.5V
V
CC
= MAX
V
CC
= MAX
–60
24
24
±10%V
CC
±5%V
CC
±10%V
CC
±5%V
CC
LIMITS
MIN
2.5
V
2.7
3.4
0.30
0.30
–0.73
0.50
V
0.50
–1.2
100
20
–0.6
–150
36
36
V
µA
µA
mA
mA
mA
mA
TYP
2
MAX
UNIT
V
O
OH
High-level
High level output voltage
V
O
OL
V
IK
I
I
I
IH
I
IL
I
OS
I
CC
NOTES:
1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable type.
2. All typical values are at V
CC
= 5V, T
amb
= 25°C.
3. Not more than one output should be shorted at a time. For testing I
OS
, the use of high-speed test apparatus and/or sample-and-hold
techniques are preferable in order to minimize internal heating and more accurately reflect operational values. Otherwise, prolonged shorting
of a High output may raise the chip temperature well above normal and thereby cause invalid readings in other parameter tests. In any
sequence of parameter tests, I
OS
tests should be performed last.
May 15, 1990
4
Philips Semiconductors
Product specification
8-bit identity comparator
74F521
AC ELECTRICAL CHARACTERISTICS
LIMITS
SYMBOL
PARAMETER
TEST
CONDITION
V
CC
= +5.0V
T
amb
= +25°C
C
L
= 50pF, R
L
= 500Ω
MIN
t
PLH
t
PHL
t
PLH
t
PHL
Propagation delay
An or Bn to Q
A=B
Propagation delay
I
A=B
to Q
A=B
Waveform 1, 2
Waveform 2
3.5
3.0
3.0
3.5
TYP
8.0
8.0
5.0
6.5
MAX
9.5
9.0
6.5
7.0
V
CC
= +5.0V
±
10%
T
amb
= 0°C to +70°C
C
L
= 50pF, R
L
= 500Ω
MIN
3.5
2.5
3.0
3.5
MAX
11.0
10.5
7.5
8.0
ns
ns
UNIT
AC WAVEFORMS
For all waveforms, V
M
= 1.5V.
An, Bn
V
M
t
PHL
An, Bn
V
M
I
A=B
t
PLH
V
M
t
PLH
V
M
t
PHL
Q
A=B
V
M
V
M
Q
A=B
V
M
V
M
SF00278
SF00279
Waveform 1.
For Inverting Outputs
Waveform 2.
For Non-Inverting Outputs
TEST CIRCUIT AND WAVEFORMS
V
CC
NEGATIVE
PULSE
V
IN
PULSE
GENERATOR
R
T
D.U.T.
V
OUT
90%
V
M
10%
t
THL (
t
f
)
C
L
R
L
t
w
V
M
10%
t
TLH (
t
r
)
0V
90%
AMP (V)
t
TLH (
t
r
)
90%
POSITIVE
PULSE
V
M
10%
t
w
t
THL (
t
f
)
AMP (V)
90%
V
M
10%
0V
Test Circuit for Totem-Pole Outputs
DEFINITIONS:
R
L
= Load resistor;
see AC ELECTRICAL CHARACTERISTICS for value.
C
L
= Load capacitance includes jig and probe capacitance;
see AC ELECTRICAL CHARACTERISTICS for value.
R
T
= Termination resistance should be equal to Z
OUT
of
pulse generators.
Input Pulse Definition
INPUT PULSE REQUIREMENTS
family
amplitude V
M
74F
3.0V
1.5V
rep. rate
1MHz
t
w
500ns
t
TLH
2.5ns
t
THL
2.5ns
SF00006
May 15, 1990
5
Power technology
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