Revised March 2000 DM74AS240 • DM74AS244 3-STATE Bus Driver/Receiver General Description Features This family of Advance Schottky 3-STATE Bus circuits are designed to provide either bidirectional or unidirectional buffer interface in Memory, Microprocessor, and Communication Systems. The output characteristics of the circuits have low impedance sufficient to drive terminated transmission lines down to 133Ω. The input characteristics of the circuits likewise have a high impedance so it will not significantly load the transmission line. The package contains eight 3-STATE buffers organized with four buffers having a common 3-STATE enable gate. The DM74AS240 and DM74AS244 are eight wide in a 20 pin package, and may be used as a 4 wide bidirectional or eight wide unidirectional. The buffer selection includes inverting and noninverting, with enable or disable 3-STATE control. ■ Advanced oxide-isolated, ion-implanted Schottky TTL process ■ Improved switching performance with less power dissipation compared with Schottky counterpart ■ Functional and pin compatible with 74LS and Schottky counterpart ■ Switching response specified into 500Ω and 50 pF ■ Specified to interface with CMOS at VOH = VCC − 2V Ordering Code: Order Number Package Number DM74AS240WM M20B Package Description 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide DM74AS240N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide DM74AS244WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide DM74AS244N 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 Diagrams DM74AS240 DM74AS244 Function Tables DM74AS240 Inputs DM74AS244 Output Inputs Output G A Y G A L L H L L L L H L L H H H X X Z L = LOW Logic Level Z H H = HIGH Logic Level © 2000 Fairchild Semiconductor Corporation X = Either LOW or HIGH Logic Level DS006298 Y Z = High Impedance www.fairchildsemi.com DM74AS240 • DM74AS244 3-STATE Bus Driver/Receiver October 1986 DM74AS240 • DM74AS244 Absolute Maximum Ratings(Note 1) Supply Voltage, VCC 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 57.0°C/W M Package 76.0°C/W Recommended Operating Conditions Symbol Parameter Min Nom Max Units 4.5 5 5.5 V VCC Supply Voltage VIH HIGH Level Input Voltage VIL LOW Level Input Voltage 0.8 V IOH HIGH Level Output Current −15 mA IOL LOW Level Output Current 64 mA TA Free Air Operating Temperature 70 °C 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, IIN = −18 mA VOH HIGH Level VCC = 4.5V, IOH = −3 mA Output Voltage Min 2.4 VCC = 4.5V, IOH = Max LOW Level Output Voltage VCC = 4.5V, IOL = Max II Input Current at Max Input Voltage VCC = 5.5V IIH HIGH Level Input Current IIL LOW Level Input Current Max Units −1.2 V 3.2 2.4 IOH = −2 mA, VCC = 4.5V to 5.5V VOL Typ V VCC−2 0.55 V Others 100 µA VCC = 5.5V, VIN = 2.7V Others 20 µA VCC = 5.5V, VIN = 0.4V AS240, (G, G), VIN = 7V 0.35 −500 (Control Inputs), DM74AS244 (G) −1000 DM74AS244 (A) IOZH HIGH Level 3-STATE Output Current VCC = 5.5V, V= 2.7V IOZL LOW Level 3-STATE IO (Note 2) Output Drive Current VCC = 5.5V, VOUT = 2.25V DM74AS240 VCC = 5.5V Output Current ICC 50 DM74AS240, VCC = 5.5V, V = 0.4V DM74AS244 Supply Current ICC DM74AS244 VCC = 5.5V Supply Current −50 −115 2 µA −50 µA −150 mA Outputs HIGH 11 17 Outputs LOW 51 75 3-STATE 24 38 Outputs HIGH 22 34 Outputs LOW 60 90 3-STATE 34 54 Note 2: The output conditions have been chosen to produce a current that closely approximates one half the true short-circuit output current, I OS. www.fairchildsemi.com µA mA mA over recommended operating free air temperature range Symbol tPLH tPHL Parameter Conditions Propagation Delay Time VCC = 4.5V to 5.5V LOW-to-HIGH Level Output R1 = R2 = 500Ω Propagation Delay Time CL = 50 pF HIGH-to-LOW Level Output From To (Input) (Output) A Min Max Units Y 2 6.5 ns A Y 2 5.7 ns tPZL Output Enable to LOW Level G Y 2 9 ns tPZH Output Enable to HIGH Level G Y 2 6.4 ns tPLZ Output Disable from LOW Level G Y 2 9.5 ns tPHZ Output Disable from HIGH Level G Y 2 5 ns Min Max Units DM74AS244 Switching Characteristics over recommended operating free air temperature range Symbol tPLH tPHL Parameter Conditions Propagation Delay Time VCC = 4.5V to 5.5V LOW-to-HIGH Level Output R1 = R2 = 500Ω Propagation Delay Time CL = 50 pF HIGH-to-LOW Level Output From To (Input) (Output) A Y 2 6.2 ns A Y 2 6.2 ns tPZL Output Enable to LOW Level G Y 2 7.5 ns tPZH Output Enable to HIGH Level G Y 2 9 ns tPLZ Output Disable from LOW Level G Y 2 9 ns tPHZ Output Disable from HIGH Level G Y 2 6 ns 3 www.fairchildsemi.com DM74AS240 • DM74AS244 DM74AS240 Switching Characteristics DM74AS240 • DM74AS244 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 DM74AS240 • DM74AS244 3-STATE Bus Driver/Receiver 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