M74HC688
8 BIT EQUALITY COMPARATOR
■ HIGH SPEED:
t
= 17ns (TYP.) at VCC = 6V
PD
■ LOW POWER DISSIPATION:
I
= 4µA(MAX.) at TA=25°C
CC
■ HIGH NOISE IMMUNITY:
V
= V
NIH
■ SYMMETRICAL OUTPUT IMPEDANCE:
|I
| = IOL = 4mA (MIN)
OH
■ BALANCED PROPAGATION DELAYS:
t
≅ t
PLH
■ WIDE OPERATING VOLTAGE RANGE:
V
(OPR) = 2V to 6V
CC
■ PIN AND FUNCTION COMPATIBLE WITH
= 28 % VCC (MIN.)
NIL
PHL
74 SERIES 688
DESCRIPTION
The M74HC688 is an high speed CMOS 8 BIT
EQUALITY COMPARATOR fabricated with silicon
gate C
2
MOS technology.
The M74HC688 compares bit for bit two 8-bit
words applied on inputs P0 - P7 and inputs Q0 Q7 and indicates whether or not they are equal. A
TSSOPDIP SOP
ORDER CODES
PACKAGE TUBE T & R
DIP M74HC688B1R
SOP M74HC688M1R M74HC688RM13TR
TSSOP M74HC688TTR
single active low enable is provided to facilitate
cascading several packages to enable
comparison of words greater than 8 bits.
All inputs are equipped with protection circuits
against static discharge and transient excess
voltage.
PIN CONNECTION AND IEC LOGIC SYMBOLS
1/9July 2001
M74HC688
INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION
PIN No SYMBOL NAME AND FUNCTION
1G
2, 4, 6, 8, 1 1,
13, 15, 17
3, 5, 7, 9, 12,
14, 16, 18
19 P = Q
10 GND Ground (0V)
20 V
TRUTH TABLE
INPUTS OUTPUT
P0 to P7 Word Inputs
Q0 to Q7 Word Outputs
CC
Enable Input (Active
LOW)
Equal to Output
Positive Supply Voltage
P, Q G
P = Q L L
P <> Q L H
XHH
X: Don’t Care
LOGIC DIAGRAM
P = Q
This log i c diagram has not be used to est i m at e propagation delays
2/9
M74HC688
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
V
V
I
I
OK
I
I
or I
CC
P
T
T
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
(*) 500mW at 65
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter Value Unit
V
V
V
T
t
r
Supply Voltage
CC
DC Input Voltage -0.5 to VCC + 0.5
I
DC Output Voltage -0.5 to VCC + 0.5
O
DC Input Diode Current
IK
DC Output Diode Current
DC Output Current
O
DC VCC or Ground Current
GND
Power Dissipation
D
Storage Temperature
stg
Lead Temperature (10 sec)
L
°C; derate to 300mW by 10mW/°C from 65°C to 85°C
Supply Voltage
CC
Input Voltage 0 to V
I
Output Voltage 0 to V
O
Operating Temperature
op
Input Rise and Fall Time VCC = 2.0V
, t
f
V
V
CC
CC
= 4.5V
= 6.0V
-0.5 to +7 V
± 20 mA
± 20 mA
± 25 mA
± 50 mA
500(*) mW
-65 to +150 °C
300 °C
2 to 6 V
CC
CC
-55 to 125 °C
0 to 1000 ns
0 to 500 ns
0 to 400 ns
V
V
V
V
3/9
M74HC688
DC SPECIFICATIONS
Symbol Parameter
V
V
V
V
I
High Level Input
IH
Voltage
Low Level Input
IL
Voltage
High Level Output
OH
Voltage
Low Level Output
OL
Voltage
I
Input Leakage
I
Current
Quiescent Supply
CC
Current
Test Condition Value
V
(V)
CC
= 25°C
A
Min. Typ. Max. Min. Max. Min. Max.
-40 to 85°C -55 to 125°C
T
2.0 1.5 1.5 1.5
6.0 4.2 4.2 4.2
2.0 0.5 0.5 0.5
6.0 1.8 1.8 1.8
2.0
4.5
6.0
4.5
6.0
2.0
4.5
6.0
4.5
6.0
6.0
6.0
IO=-20 µA
I
=-20 µA
O
I
=-20 µA
O
I
=-4.0 mA
O
I
=-5.2 mA
O
IO=20 µA
I
=20 µA
O
I
=20 µA
O
I
=4.0 mA
O
I
=5.2 mA
O
= VCC or GND
V
I
= VCC or GND
V
I
1.9 2.0 1.9 1.9
4.4 4.5 4.4 4.4
5.9 6.0 5.9 5.9
4.18 4.31 4.13 4.10
5.68 5.8 5.63 5.60
0.0 0.1 0.1 0.1
0.0 0.1 0.1 0.1
0.0 0.1 0.1 0.1
0.17 0.26 0.33 0.40
0.18 0.26 0.33 0.40
± 0.1 ± 1 ± 1 µA
44080µA
Unit
V4.5 3.15 3.15 3.15
V4.5 1.35 1.35 1.35
V
V
AC ELECTRICAL CHARACTERISTICS (C
Test Condition Value
Symbol Parameter
t
TLH tTHL
t
PLH tPHL
Output Transition
Time
Propagation Delay
Time
(Pn, Qn - P=Q
t
PLH tPHL
Propagation Delay
Time
(G - P=Q
)
V
CC
(V)
2.0 30 75 95 110
6.0 7131619
2.0 60 170 215 255
)
6.0 17 29 37 43
2.0 40 110 140 165
6.0 10 19 24 28
= 50 pF, Input tr = tf = 6ns)
L
T
= 25°C
A
Min. Typ. Max. Min. Max. Min. Max.
-40 to 85°C -55 to 125°C
Unit
ns4.5 8151922
ns4.5 21 34 43 51
ns4.5 13 22 28 33
4/9
M74HC688
CAPACITIVE CHARACTERISTICS
Test Condition Value
T
Symbol Parameter
C
C
Input Capacitance
IN
Power Dissipation
PD
Capacitance (note
V
CC
(V)
= 25°C
A
Min. Typ. Max. Min. Max. Min. Max.
5101010pF
32 pF
1)
1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without
load. (R ef er to Test Circui t). Averag e operating current can be obtained by the following equation. I
TEST CIRCUIT
-40 to 85°C -55 to 125°C
= CPD x VCC x fIN + I
CC(opr)
CC
Unit
CL = 50pF/150p F or equivalen t (includes ji g and probe capa ci t ance)
R
= Z
of pulse generator (typically 50Ω)
T
OUT
WAVEFORM : PROPAGATION DELAY TIME (f=1MHz; 50% duty cycle)
5/9
M74HC688
DIM.
a1 0.254 0.010
B 1.39 1.65 0.055 0.065
b 0.45 0.018
b1 0.25 0.010
D 25.4 1.000
E 8.5 0.335
e 2.54 0.100
e3 22.86 0.900
F 7.1 0.280
Plastic DIP-20 (0.25) MECHANICAL DATA
mm. inch
MIN. TYP MAX. MIN. TYP. MAX.
I 3.93 0.155
L 3.3 0.130
Z 1.34 0.053
6/9
P001J
SO-20 MECHANICAL DATA
M74HC688
DIM.
MIN. TYP MAX. MIN. TYP. M AX.
A 2.65 0.104
a1 0.1 0.2 0.004 0.008
a2 2.45 0.096
b 0.35 0.49 0.014 0.019
b1 0.23 0.32 0.009 0.012
C 0.5 0.020
c1 45° (typ.)
D 12.60 13.00 0.496 0.512
E 10.00 10.65 0.393 0.419
e 1.27 0.050
e3 11.43 0.450
F 7.40 7.60 0.291 0.300
L 0.50 1.27 0.020 0.050
M 0.75 0.029
S8° (max.)
mm. inch
PO13L
7/9
M74HC688
TSSOP20 MECHANICAL DATA
mm. inch
DIM.
MIN. TYP MAX. MIN. TYP. M AX.
A 1.2 0.047
A1 0.05 0.15 0.002 0.004 0.006
A2 0.8 1 1.05 0.031 0.039 0.041
b 0.19 0.30 0.007 0.012
c 0.09 0.20 0.004 0.0089
D 6.4 6.5 6.6 0.252 0.256 0.260
E 6.2 6.4 6.6 0.244 0.252 0.260
E1 4.3 4.4 4.48 0.169 0.173 0.176
e 0.65 BSC 0.0256 BSC
K0° 8°0° 8°
L 0.45 0.60 0.75 0.018 0.024 0.030
A2
A
A1
b
e
K
c
L
E
D
E1
PIN 1 IDENTIFICATION
8/9
1
0087225C
M74HC688
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