Revised April 2000 DM74ALS520 • DM74ALS521 8-Bit Comparator General Description Features These comparators perform an “equal to” comparison of two 8-bit words with provision for expansion or external enabling. The matching of the two 8-bit input plus a logic LOW on the EN input produces the output A = B on the DM74ALS520 and DM74ALS521. The DM74ALS520 and DM74ALS521 have totem pole outputs for wire AND cascading. Additionally, the DM74ALS520 is provided with B input pull up termination resistors for analog or switch data. ■ Switching specifications at 50 pF ■ Switching specifications guaranteed over full temperature and VCC range ■ Advanced oxide-isolated, ion-implanted Schottky TTL process ■ Functionally and pin for pin compatible with LS family counterpart ■ Improved output transient handling capability Ordering Code: Ordering Code Package Number DM74ALS520WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Package Description DM74ALS520N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide DM74ALS521WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide SM74ALS521N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Connection Diagram Function Table Inputs Output A=B EN Data L A=B L L A≠B H H X H H = HIGH Logic Level L = LOW Logic Level X = Don't Care © 2000 Fairchild Semiconductor Corporation DS006114 www.fairchildsemi.com DM74ALS520 • DM74ALS521 8-Bit Comparator September 1986 DM74ALS520 • DM74ALS521 Logic Diagram www.fairchildsemi.com 2 Supply Voltage 7V Input Voltage 7V 0°C to +70°C Operating Free Air Temperature Range Note 1: The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation. −65°C to +150°C Storage Temperature Range Typical θJA N Package 62.0°C/W M Package 82.0°C/W Recommended Operating Conditions Symbol Parameter Min Nom Max 4.5 5 5.5 Units VCC Supply Voltage VIH HIGH Level Input Voltage VIL LOW Level Input Voltage 0.8 V IOH HIGH Level Output Current −2.6 mA IOL LOW Level Output Current 24 mA TA Free Air Operating Temperature 70 °C V 2 V 0 Electrical Characteristics over recommended operating free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C. Symbol Parameter Conditions VIK Input Clamp Voltage VCC = 4.5V, II = −18 mA VOH HIGH Level VCC = 4.5V to 5.5V Output Voltage IOH = −400 µA Min Typ Max Units −1.5 V VCC − 2 VCC = 4.5V V 2.4 IOH = Max VOL LOW Level Output Voltage VCC = 4.5V IOL = 24 mA II Max HIGH VCC = 5.5V VIH = 5.5V Input Current 3.2 V 0.35 B Input DM74ALS520 0.5 V 0.1 mA VIH = 7V, All Others HIGH Level VCC = 5.5V, All Others Input Current VIH = 2.7V B Input DM74ALS520 −200 Low Level Input VCC = 5.5V, B Input DM74ALS520 −0.6 mA Current VIL = 0.4V All Others −0.1 mA IO Output Drive Current VCC = 5.5V VO = 2.25V −112 mA ICC Supply Current VCC = 5.5V (Note 2) 19 mA IIH IIL 20 −30 12 µA Note 2: ICC is measured with EN grounded, A and B inputs at 4.5V and outputs OPEN. Switching Characteristics over recommended operating free air temperature range Symbol tPLH tPHL Parameter Conditions Output Min Max Units A=B 3 12 ns A=B 5 20 ns EN A=B 2 12 ns EN A=B 5 22 ns VCC = 4.5V to 5.5V LOW-to-HIGH Level Output CL = 50 pF Data Propagation Delay Time RL = 500Ω A or B A or B Data Propagation Delay Time LOW-to-HIGH Level Output tPHL To Input Propagation Delay Time HIGH-to-LOW Level Output tPLH From Propagation Delay Time HIGH-to-LOW Level Output 3 www.fairchildsemi.com DM74ALS520 • DM74ALS521 Absolute Maximum Ratings(Note 1) DM74ALS520 • DM74ALS521 Physical Dimensions inches (millimeters) unless otherwise noted 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Package Number M20B www.fairchildsemi.com 4 DM74ALS520 • DM74ALS521 8-Bit 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. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. www.fairchildsemi.com 5 www.fairchildsemi.com