Revised February 2000 DM74ALS1240A Octal 3-STATE Bus Driver General Description Features These octal 3-STATE bus drivers are designed to provide the designer with flexibility in implementing a bus interface with memory, microprocessor, or communication systems, and are low power dissipation versions of the DM74ALS240A and DM74ALS241A. The output 3-STATE gating control is organized into two separate groups of four buffers. The DM74ALS1240A control inputs symmetrically enable the respective outputs when set logic LOW. The 3STATE circuitry contains a feature that maintains the buffer outputs in 3-STATE (high impedance state) during power supply ramp-up or ramp-down. This eliminates bus glitching problems that arise during power-up and power-down. ■ Advanced oxide-isolated, ion-implanted Schottky TTL process ■ Switching response specified into 500Ω and 50 pF load ■ Switching response specifications guaranteed over full temperature and VCC supply range ■ PNP input design reduces input loading ■ Low power dissipation version ■ Low level drive current: 74ALS = 16 mA Ordering Code: Order Number Package Number DM74ALS1240AWM M20B Package Description 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Connection Diagram Logic Diagram Function Table Input Output G A Y L L H L H L H X Z H = HIGH Level Logic State L = LOW Level Logic State X = Don't Care (Either LOW or HIGH Level Logic State) Z = High Impedance (OFF) State © 2000 Fairchild Semiconductor Corporation DS006261 www.fairchildsemi.com DM74ALS1240A Octal 3-STATE Bus Driver September 1986 DM74ALS1240A Absolute Maximum Ratings(Note 1) Supply Voltage 7V Input Voltage 7V Voltage Applied to Disabled Output 5.5V 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. 0°C to +70°C Operating Free Air Temperature Range −65°C to +150°C Storage Temperature Range Typical θJA N Package 60.5°C/W M Package 78.0°C/W Recommended Operating Conditions Symbol Parameter Min Typ Max 4.5 5 5.5 Units VCC Supply Voltage VIH HIGH Level Input Voltage V VIL LOW Level Input Voltage 0.8 V IOH HIGH Level Output Current −15 mA IOL LOW Level Output Current 16 mA TA Operating Free Air Temperature 70 °C 2 V 0 Electrical Characteristics over recommended operating free air temperature range (unless otherwise specified) Symbol Parameter Conditions Min VIK Input Clamp Voltage VCC = 4.5V, II = −18 mA VOH HIGH Level VCC = 4.5V to 5.5V IOH = −0.4 mA Output Voltage VCC = 4.5V IOH = −3 mA IOH = Max VOL LOW Level VCC = 4.5V Output Voltage II Input Current at Maximum Input Voltage Typ Max Units −1.2 V VCC − 2 V 2.4 V 2 V IOL = 12 mA 0.25 0.4 IOL = 24 mA 0.35 0.5 V 0.1 mA VCC = 5.5V, VI = 7V V IIH HIGH Level Input Current VCC = 5.5V, VI = 2.7V 20 µA IIL LOW Level Input Current VCC = 5.5V, VIL = 0.4V −0.1 mA IO Output Drive Current VCC = 5.5V, VO = 2.25V −112 mA IOZH HIGH Level 3-STATE VCC = 5.5V, VO = 2.7V 20 µA VCC = 5.5V, VO = 0.4V −20 µA Output Current IOZL LOW Level 3-STATE Output Current ICC Supply Current VCC = 5.5V Outputs 3-STATE www.fairchildsemi.com 2 −30 Outputs HIGH 5 8 mA Outputs LOW 8 14 mA 8 13 mA over recommended operating free air temperature range VCC = 4.5V to 5.5V, CL = 50 pF, Symbol tPLH Parameter To R1 = 500Ω, R2 = 500Ω, (Input) (Output) TA = Min to Max Propagation Delay Time LOW-to-HIGH Level Output tPHL From Propagation Delay Time A Output Enable Time to HIGH Level Output tPZL Output Enable Time G Output Disable Time from HIGH Level Output tPLZ Output Disable Time Max 2 13 ns 2 13 ns 4 20 ns 6 22 ns 2 10 ns 3 13 ns Y to LOW Level Output tPHZ Min Y HIGH-to-LOW Level Output tPZH Units G Y from LOW Level Output 3 www.fairchildsemi.com DM74ALS1240A Switching Characteristics DM74ALS1240A Octal 3-STATE Bus Driver Physical Dimensions inches (millimeters) unless otherwise noted 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Package Number M20B 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 www.fairchildsemi.com 4