Revised November 1999 74AC521 • 74ACT521 8-Bit Identity Comparator General Description Features The AC/ACT521 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. ■ ICC reduced by 50% ■ Compares two 8-bit words in 6.5 ns typ ■ Expandable to any word length ■ 20-pin package ■ Outputs source/sink 24 mA ■ ACT521 has TTL-compatible inputs Ordering Code: Order Number Package Number 74AC521SC M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body Package Description 74AC521SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide 74AC521PC N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide 74ACT521SC M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body 74ACT521SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide 74ACT521PC N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering table. Logic Symbols Connection Diagram IEEE/IEC Pin Descriptions Pin Names Description A0–A7 Word A Inputs B0–B7 Word B Inputs TA = B Expansion or Enable Input OA = B Identity Output FACT is a trademark of Fairchild Semiconductor Corporation. © 1999 Fairchild Semiconductor Corporation DS009964 www.fairchildsemi.com 74AC521 • 74ACT521 8-Bit Identity Comparator November 1988 74AC521 • 74ACT521 Truth Table Logic Diagram Inputs Outputs A, B IA = B OA = B L A = B (Note 1) L L A≠Β H H A = B (Note 1) H H A≠Β H H = HIGH Voltage Level L = LOW Voltage Level Note 1: A0 = B0, A1 = B1, A2 = B2, etc. Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays. Applications Ripple Expansion Parallel Expansion www.fairchildsemi.com 2 Recommended Operating Conditions −0.5V to +7.0V Supply Voltage (VCC) DC Input Diode Current (IIK) VI = −0.5V −20 mA VI = VCC + 0.5V +20 mA DC Input Voltage (VI) Supply Voltage (VCC) −0.5V to VCC + 0.5V DC Output Diode Current (IOK) VO = −0.5V −20 mA VO = VCC + 0.5V +20 mA DC Output Voltage (VO) 4.5V to 5.5V 0V to VCC Output Voltage (VO) 0V to VCC −40°C to +85°C Operating Temperature (TA) Minimum Input Edge Rate (∆V/∆t) −0.5V to VCC + 0.5V AC Devices VIN from 30% to 70% of VCC ±50 mA VCC @ 3.3V, 4.5V, 5.5V DC VCC or Ground Current 125 mV/ns Minimum Input Edge Rate (∆V/∆t) ±50 mA per Output Pin (ICC or IGND) Storage Temperature (TSTG) 2.0V to 6.0V ACT Input Voltage (VI) DC Output Source or Sink Current (IO) AC ACT Devices −65°C to +150°C VIN from 0.8V to 2.0V Junction Temperature (TJ) VCC @ 4.5V, 5.5V PDIP 140°C 125 mV/ns Note 2: Absolute maximum ratings are those values beyond which damage to the device may occur. The databook specifications should be met, without exception, to ensure that the system design is reliable over its power supply, temperature, output/input loading variables. Fairchild does not recommend operation of FACT circuits outside databook specifications. DC Electrical Characteristics for AC Symbol VIH VIL VOH Parameter TA = +25°C VCC TA = −40°C to +85°C (V) Typ Guaranteed Limits Minimum HIGH Level 3.0 1.5 Input Voltage 4.5 2.25 3.15 3.15 5.5 2.75 3.85 3.85 2.1 Units Maximum LOW Level 3.0 1.5 0.9 0.9 Input Voltage 4.5 2.25 1.35 1.35 5.5 2.75 1.65 1.65 Minimum HIGH Level 3.0 2.99 2.9 2.9 Output Voltage 4.5 4.49 4.4 4.4 5.5 5.49 5.4 5.4 3.0 2.56 2.46 4.5 3.86 3.76 5.5 4.86 4.76 Conditions VOUT = 0.1V 2.1 V or VCC − 0.1V VOUT = 0.1V V or VCC − 0.1V V IOUT = −50 µA VIN = V IL or VIH VOL Maximum LOW Level 3.0 0.002 0.1 0.1 Output Voltage 4.5 0.001 0.1 0.1 5.5 0.001 0.1 0.1 3.0 0.36 0.44 4.5 0.36 0.44 5.5 0.36 0.44 5.5 ±0.1 IOH = −12 mA V IOH = −24 mA IOH = −24 mA (Note 3) V IOUT = 50 µA VIN = V IL or VIH IOL = 12 mA V IOL = 24 mA IOL = 24 mA (Note 3) IIN Maximum Input (Note 5) Leakage Current ±1.0 µA VI = V CC, GND IOLD Minimum Dynamic 5.5 75 mA VOLD = 1.65V Max IOHD Output Current (Note 4) 5.5 −75 mA ICC Maximum Quiescent (Note 5) Supply Current 5.5 4.0 40.0 µA VOHD = 3.85V Min VIN = V CC or GND Note 3: All outputs loaded; thresholds on input associated with output under test. Note 4: Maximum test duration 2.0 ms, one output loaded at a time. Note 5: IIN and ICC @ 3.0V are guaranteed to be less than or equal to the respective limit @ 5.5V VCC. 3 www.fairchildsemi.com 74AC521 • 74ACT521 Absolute Maximum Ratings(Note 2) 74AC521 • 74ACT521 DC Electrical Characteristics for ACT Symbol VIH VIL VOH Parameter TA = +25°C VCC (V) Typ TA = −40°C to +85°C Units Conditions Guaranteed Limits Minimum HIGH Level 4.5 1.5 2.0 2.0 Input Voltage 5.5 1.5 2.0 2.0 Maximum LOW Level 4.5 1.5 0.8 0.8 Input Voltage 5.5 1.5 0.8 0.8 Minimum HIGH Level 4.5 4.49 4.4 4.4 Output Voltage 5.5 5.49 5.4 5.4 3.86 3.76 V V VOUT = 0.1V or VCC − 0.1V VOUT = 0.1V or VCC − 0.1V V IOUT = −50 µA V IOH = −24 mA VIN = V IL or VIH 4.5 5.5 VOL IOH = −24 mA (Note 6) 4.86 4.76 Maximum LOW Level 4.5 0.001 0.1 0.1 Output Voltage 5.5 0.001 0.1 0.1 4.5 0.36 0.44 5.5 0.36 0.44 5.5 ±0.1 ±1.0 µA VI = V CC, GND 1.5 mA VI = V CC − 2.1V VOLD = 1.65V Max V IOUT = 50 µA V IOL = 24 mA VIN = V IL or VIH IIN Maximum Input Leakage Current ICCT Maximum 5.5 ICC/Input 0.6 IOL = 24 mA (Note 6) IOLD Minimum Dynamic 5.5 75 mA IOHD Output Current (Note 7) 5.5 −75 mA ICC Maximum Quiescent Supply Current 5.5 4.0 µA 40.0 VOHD = 3.85V Min VIN = V CC or GND Note 6: All outputs loaded; thresholds on input associated with output under test. Note 7: Maximum test duration 2.0 ms, one output loaded at a time. AC Electrical Characteristics for AC Symbol tPLH tPHL tPLH tPHL Parameter VCC TA = +25°C (V) CL = 50 pF TA = −40°C to +85°C CL = 50 pF (Note 8) Min Typ Max Min Max Propagation Delay 3.3 3.5 7.0 11.0 3.0 12.0 An or Bn to OA = B 5.0 2.5 5.0 8.0 2.0 9.0 Propagation Delay 3.3 4.5 7.5 11.5 3.5 12.5 An or Bn to OA = B 5.0 3.0 5.5 8.5 2.5 9.0 Propagation Delay 3.3 3.0 5.5 8.0 2.5 9.0 IA = B to OA = B 5.0 2.5 4.0 6.0 2.0 7.0 Propagation Delay 3.3 3.0 5.5 8.0 2.5 9.0 IA = B to OA = B 5.0 2.0 4.0 6.0 2.0 7.0 Note 8: Voltage Range 3.3 is 3.3V ± 0.3V Voltage Range 5.0 is 5.0V ± 0.5V www.fairchildsemi.com 4 Units ns ns ns ns Symbol tPLH Parameter Propagation Delay An or Bn to OA = B tPHL Propagation Delay An or Bn to OA = B tPLH Propagation Delay IA = B to OA = B tPHL Propagation Delay IA = B to OA = B VCC TA = +25°C (V) CL = 50 pF TA = −40°C to +85°C CL = 50 pF Units (Note 9) Min Typ Max Min Max 5.0 3.0 5.5 9.0 2.5 9.5 ns 5.0 3.0 6.0 10.0 2.5 11.0 ns 5.0 2.0 4.0 6.5 2.0 7.0 ns 5.0 2.5 5.0 7.5 2.0 8.0 ns Note 9: Voltage Range 5.0 is 5.0V ± 0.5V Capacitance Typ Units CIN Symbol Input Capacitance Parameter 4.5 pF VCC = OPEN CPD Power Dissipation Capacitance 40 pF VCC = 5.0V 5 Conditions www.fairchildsemi.com 74AC521 • 74ACT521 AC Electrical Characteristics for ACT 74AC521 • 74ACT521 Physical Dimensions inches (millimeters) unless otherwise noted 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body Package Number M20B www.fairchildsemi.com 6 74AC521 • 74ACT521 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide Package Number M20D 7 www.fairchildsemi.com 74AC521 • 74ACT521 8-Bit Identity Comparator Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide Package Number N20A Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications. 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