Motorola MC74F85N, MC74F85D, MC74F85J, MC54F85J, MC54F85N Datasheet
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4-36
FAST AND LS TTL DATA
4-BIT MAGNITUDE COMPARATOR
The MC54/74F85 is a 4-Bit Magnitude Comparator which compares two
4-Bit words (A0-A3, B0-B3), A3, B3 being the most significant inputs. Operation
is not restricted to binary codes; the device will work with any monotonic code.
Three Outputs are provided: “A greater than B” (0A > B), “A less than B” (0
A
< B), “A equal to B” (0A = B). Three Expander Inputs, IA > B, IA < B, IA = B, allow
cascading without external gates. For proper compare operation, the Expander Inputs to the least significant position must be connected as follows: IA <
B
= IA > B = L, IA = B = H. For serial (ripple) expansion the 0A > B, 0A < B Outputs
are connected respectively to the IA > B and IA = B inputs of the next most significant comparator, as shown in Figure 1. Refer to applications section of
data sheet for high speed method of comparing large words.
• High Impedance NPN Base Inputs for Reduced Loading (20 µA in
HIGH and LOW States)
• Magnitude Comparison of any Binary Words
• Serial or Parallel Expansion Without Extra Gating
• ESD
>
4000 Volts
CONNECTION DIAGRAM
1516 14 13 12 11 10
21 3 4 5 6 7
V
CC
9
8
A3B2A2A1B1A0B
0
B3IA<BIA=BIA>BA>B A=B A<B GND
GUARANTEED OPERATING RANGES
Symbol Parameter Min Typ Max Unit
V
CC
Supply Voltage 54, 74 4.5 5.0 5.5 V
T
A
Operating Ambient Temperature Range
54 –55 25 125
°C
A
74 0 25 70
I
OH
Output Current High 54, 74 –1.0 mA
I
OL
Output Current Low 54, 74 20 mA
MC54/74F85
4-BIT MAGNITUDE COMPARATOR
FAST SCHOTTKY TTL
J SUFFIX
CERAMIC
CASE 620-09
N SUFFIX
PLASTIC
CASE 648-08
16
1
16
1
ORDERING INFORMATION
MC74FXXJ Ceramic
MC74FXXN Plastic
MC74FXXD SOIC
16
1
D SUFFIX
SOIC
CASE 751B-03
4-37
FAST AND LS TTL DATA
MC54/74F85
FUNCTION TABLE
Comparing Inputs Expansion Inputs Outputs
A3, B
3
A2, B
2
A1, B
1
A0, B
0
IA >
B
IA <
B
IA =
B
A > B A < B A = B
A3 > B
3
X X X X X X H L L
A3 < B
3
X X X X X X L H L
A3 = B
3
A2 > B
2
X X X X X H L L
A3 = B
3
A2 < B
2
X X X X X L H L
A3 = B
3
A2 = B
2
A1 > B
1
X X X X H L L
A3 = B
3
A2 = B
2
A1 < B
1
X X X X L H L
A3 = B
3
A2 = B
2
A1 = B
1
A0 > B
0
X X X H L L
A3 = B
3
A2 = B
2
A1 = B
1
A0 < B
0
X X X L H L
A3 = B
3
A2 = B
2
A1 = B
1
A0 = B
0
H L L H L L
A3 = B
3
A2 = B
2
A1 = B
1
A0 = B
0
L H L L H L
A3 = B
3
A2 = B
2
A1 = B
1
A0 = B
0
L L H L L H
A3 = B
3
A2 = B
2
A1 = B
1
A0 = B
0
X X H L L H
A3 = B
3
A2 = B
2
A1 = B
1
A0 = B
0
H H L L L L
A3 = B
3
A2 = B
2
A1 = B
1
A0 = B
0
L L L H H L
H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Limits
Symbol Parameter Min Typ Max Unit Test Conditions
V
IH
Input HIGH Voltage 2.0 V Guaranteed Input HIGH Voltage
V
IL
Input LOW Voltage 0.8 V Guaranteed Input LOW Voltage
V
IK
Input Clamp Diode Voltage –1.2 V VCC = MIN, IIN = –18 mA
V
OH
Output HIGH Voltage 54, 74 2.5 V IOH = –1.0 mA VCC = 4.50 V
74 2.7 VCC = 4.75 V
V
OL
Output LOW Voltage 0.5 V IOL = 20 mA, VCC = MIN
I
IH
Input HIGH Current 20 µA VCC = MAX, VIN = 2.7 V
0.1 mA VCC = 0 V, VIN = 7.0 V
I
IL
Input LOW Current –20 µA VCC = MAX, VIN = 0.5 V
I
OS
Output Short Circuit Current (Note 2) –60 –150 mA VCC = MAX, V
OUT
= 0 V
Total Supply Current
I
CC
HIGH VIN = HIGH 50
mA VCC = MAX
LOW An = Bn = I
A-B
= GND: I
A>B
= I
A<B
= 4.5 V 54
CC
= MAX
NOTES:
1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable device type.
2. Not more than one output should be shorted at a time, nor for more than 1 second.
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