MC54/74F521 8-BIT IDENTITY COMPARATOR The MC54/74F521 is an expandable 8-bit comparator. It compares two words of up to eight bits each and provides a LOW output when the two words match bit for bit. The expansion input IA = B also serves as an active-LOW enable input. 8-BIT IDENTITY COMPARATOR • Compares Two 8-Bit Words in 6.5 ns Typical • Expandable to Any Word Length • 20-Pin Package FAST SCHOTTKY TTL CONNECTION DIAGRAM (TOP VIEW) VCC 20 OA = B 19 B7 18 A7 17 B6 16 A6 15 B5 14 A5 13 B4 12 A4 11 J SUFFIX CERAMIC CASE 732-03 20 1 1 2 3 4 5 6 7 8 9 10 IA = B A0 B0 A1 B1 A2 B2 A3 B3 GND N SUFFIX PLASTIC CASE 738-03 20 1 DW SUFFIX SOIC CASE 751D-03 20 1 ORDERING INFORMATION MC54FXXXJ Ceramic MC74FXXXN Plastic MC74FXXXDW SOIC GUARANTEED OPERATING RANGES Symbol Parameter Min Typ Max Unit 54, 74 4.5 5.0 5.5 V 54 –55 25 125 °C 74 0 25 VCC Supply Voltage TA Operating Ambient Temperature Range IOH Output Current High 54,74 –1.0 mA IOL Output Current Low 54, 74 20 mA FAST AND LS TTL DATA 4-195 70 MC54/74F521 LOGIC DIAGRAM LOGIC SYMBOL 1 A0 B0 A1 B1 A2 B2 A3 B3 OA = B A4 B4 19 A5 B5 A6 B6 A7 B7 IA = B B7 A7 B6 A6 B5 A5 B4 OA = B A4 B3 A3 B2 A2 B1 A1 B0 A0 18 17 16 15 14 13 12 11 9 8 7 6 5 4 3 2 VCC = PIN 20 GND = PIN 10 IA = B NOTE: This diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays. DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits Symbol PARAMETER VIH Input HIGH Voltage VIL Input LOW Voltage VIK Input Clamp Diode Voltage VOH Output HIGH Voltage VOL Output LOW Voltage Min Typ Max 2.0 54, 74 2.5 74 2.7 Test Conditions V Guaranteed Input HIGH Voltage 0.8 V Guaranteed Input LOW Voltage –1.2 V IIN = – 18 mA VCC = MIN V IOH = – 1.0 mA VCC = 4.5 V 3.4 3.4 0.35 Unit V IOH = – 1.0 mA VCC = 4.75 V 0.5 V IOL = 20 mA VCC = MIN 20 µA VIN = 2.7 V VCC = MAX IIH Input HIGH Current 100 µA VIN = 7.0 V IIL Input LOW Current –0.6 mA VIN = 0.5 V VCC = MAX IOS Output Short Circuit Current (Note 2) –150 mA VOUT = 0 V VCC = MAX ICC Power Supply Current 32 mA IA = B = GND VCC = MAX – 60 21 NOTES: 1. For conditions shown as MIN or MAX, use the appropriate value specified under guaranteed operating ranges. 2. Not more than one output should be shorted at a time, nor for more than 1 second. FAST AND LS TTL DATA 4-196 MC54/74F521 FUNCTION TABLE Inputs Output IA = B A, B OA = B L A = B* L L A≠B H H A = B* H H A≠B H H = HIGH Voltage Level L = LOW Voltage Level *A0 = B0, A1 = B1, A2 = B2, etc. AC CHARACTERISTICS Symbol Parameter 54/74F 54F 74F TA = +25°C TA = –55°C to +125°C TA = 0°C to +70°C VCC = +5.0 V VCC = 5.0 V ± 10% VCC = 5.0 V ± 10% CL = 50 pF CL= 50 pF CL= 50 pF Min Typ Max Min Max Min Max Unit ns tPLH Propagation Delay 2.5 6.5 10 2.5 15 2.5 11 tPHL An or Bn to OA = B 3.0 6.5 10 3.0 12 3.0 11 tPLH Propagation Delay 2.5 4.5 6.5 2.5 8.5 2.5 7.5 tPHL IA = B to OA = B 3.5 5.0 9.0 3.5 10 3.5 10 Ripple Expansion A0 B0 ENABLE LOW ...... A7 B7 A8 B8 A15 B15 ....... IA = B IA = B IA = B A16 B16 A23 B23 ....... OA = B OA = B OA = B Parallel Expansion A0 B0 A7 B7 ...... IA = B A8 B8 A15 B15 ....... IA = B OA = B OA = B Figure 1. Applications FAST AND LS TTL DATA 4-197 A16 B16 A23 B23 ....... IA = B OA = B ns