Motorola MC74F85N, MC74F85D, MC74F85J, MC54F85J, MC54F85N Datasheet

4-BIT MAGNITUDE COMPARATOR

The MC54/74F85 is a 4-Bit Magnitude Comparator which compares two 4-Bitwords(A0-A3,B0-B3),A3,B3beingthemostsignificantinputs. Operation is not restricted to binary codes; the device will work with any monotonic code.

Three Outputs are provided: ªA greater than Bº (0 >

B

), ªA less than Bº (0

A

A

<

B

), ªA equal to Bº (0 =

B

). Three Expander Inputs, I

A

>

B

, I

A

<

B

, I

A

=

B

, allow

A

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

VCC		A3		B2		A2		A1		B1		A0		B0
16		15		14		13		12		11		10	9

	1		2		3		4		5		6		7		8
	B3	IA<B			IA=B		IA>B		A>B		A=B		A<B	GND

GUARANTEED OPERATING RANGES

MC54/74F85

4-BIT MAGNITUDE COMPARATOR

FAST SCHOTTKY TTL

			J SUFFIX
			CERAMIC
			CASE 620-09
16	1
			N SUFFIX
			PLASTIC
16			CASE 648-08
	1
			D SUFFIX
	16		SOIC
			CASE 751B-03
		1

ORDERING INFORMATION

MC74FXXJ Ceramic

MC74FXXN Plastic

MC74FXXD SOIC

Symbol		Parameter		Min	Typ	Max	Unit
VCC	Supply Voltage		54, 74	4.5	5.0	5.5	V
TA	Operating Ambient Temperature Range		54	±55	25	125	°C
			74	0	25	70
IOH	Output Current	High	54, 74			±1.0	mA
IOL	Output Current	Low	54, 74			20	mA

FAST AND LS TTL DATA

4-36

MC54/74F85

FUNCTION TABLE

	Comparing Inputs				Expansion Inputs					Outputs
A3, B3	A2, B2	A1, B1	A0, B0	IA > B		IA < B		IA = B	A > B	A < B	A = B
A3 > B3	X	X	X	X		X		X	H	L	L
A3 < B3	X	X	X	X		X		X	L	H	L
A3 = B3	A2 > B2	X	X	X		X		X	H	L	L
A3 = B3	A2 < B2	X	X	X		X		X	L	H	L
A3 = B3	A2 = B2	A1 > B1	X	X		X		X	H	L	L
A3 = B3	A2 = B2	A1 < B1	X	X		X		X	L	H	L
A3 = B3	A2 = B2	A1 = B1	A0 > B0	X		X		X	H	L	L
A3 = B3	A2 = B2	A1 = B1	A0 < B0	X		X		X	L	H	L
A3 = B3	A2 = B2	A1 = B1	A0 = B0	H		L		L	H	L	L
A3 = B3	A2 = B2	A1 = B1	A0 = B0	L		H		L	L	H	L
A3 = B3	A2 = B2	A1 = B1	A0 = B0	L		L		H	L	L	H
A3 = B3	A2 = B2	A1 = B1	A0 = B0	X		X		H	L	L	H
A3 = B3	A2 = B2	A1 = B1	A0 = B0	H		H		L	L	L	L
A3 = B3	A2 = B2	A1 = B1	A0 = B0	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
VIH	Input HIGH Voltage		2.0			V	Guaranteed Input HIGH Voltage
VIL	Input LOW Voltage				0.8	V	Guaranteed Input LOW Voltage
VIK	Input Clamp Diode Voltage				±1.2	V	VCC = MIN, IIN = ±18 mA
VOH	Output HIGH Voltage	54, 74	2.5			V	IOH = ±1.0 mA	VCC = 4.50 V
		74	2.7					VCC = 4.75 V
VOL	Output LOW Voltage				0.5	V	IOL = 20 mA, VCC = MIN
IIH	Input HIGH Current				20	μA	VCC = MAX, VIN = 2.7 V
					0.1	mA	VCC = 0 V, VIN = 7.0 V
IIL	Input LOW Current				±20	μA	VCC = MAX, VIN = 0.5 V
IOS	Output Short Circuit Current (Note 2)		±60		±150	mA	VCC = MAX, VOUT = 0 V
	Total Supply Current
ICC	HIGH VIN = HIGH				50	mA	VCC = MAX
	LOW An = Bn = IA-B = GND: IA>B = IA<B = 4.5 V				54

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.

FAST AND LS TTL DATA

4-37