MC74VHCT240A Octal Bus Buffer/Line Driver Inverting with 3State Outputs The MC74VHCT240A is an advanced high speed CMOS octal bus buffer fabricated with silicon gate CMOS technology. It achieves high speed operation similar to equivalent Bipolar Schottky TTL while MC74VHCT240A 218 OEA 1 20 V CC A1 YA1 A1 2 19 OEB 4 16 A2 YA2 YB4 3 18 YA1 A2 4 17 B4 6 14 A3 YA3 YB3 5 16 YA2 8 12 A3 6 15 B3 A4 YA4 DATA INVERTING YB2 7 14 YA3 INPUTS OUTPUTS 11 9 B1 YB1 A4 8 13 B2 YB1 9 12 YA4 13 7 B2 YB2 GND 10 11 B1 15 5 B3 YB3 Figure 2. Pin Assignment 17 3 B4 YB4 FUNCTION TABLE INPUTS OUTPUTS OEA, OEB A, B YA, YB 1 OUTPUT OEA 19 ENABLES L L H OEB L H L H X Z Figure 1. Logic Diagram MAXIMUM RATINGS Symbol Parameter Value Unit This device contains protection circuitry to guard against damage V DC Supply Voltage 0.5 to + 7.0 V CC due to high static voltages or electric V DC Input Voltage 0.5 to + 7.0 V fields. However, precautions must in be taken to avoid applications of any V DC Output Voltage Output in 3State 0.5 to + 7.0 V out voltage higher than maximum rated High or Low State 0.5 to V + 0.5 CC voltages to this highimpedance cir- cuit. For proper operation, V and I Input Diode Current 20 mA in IK V should be constrained to the out I Output Diode Current (V < GND V > V ) 20 mA OK OUT OUT CC range GND (V or V ) V . in out CC Unused inputs must always be I DC Output Current, per Pin 25 mA out tied to an appropriate logic voltage I DC Supply Current, V and GND Pins 75 mA CC CC level (e.g., either GND or V ). CC Unused outputs must be left open. P Power Dissipation in Still Air, SOIC Package 500 mW D TSSOP Package 450 T Storage Temperature 65 to + 150 C stg Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. Derating SOIC Package: 7 mW/ C from 65 to 125 C TSSOP Package: 6.1 mW/ C from 65 to 125 C RECOMMENDED OPERATING CONDITIONS Symbol Parameter Min Max Unit V DC Supply Voltage 4.5 5.5 V CC V DC Input Voltage 0 5.5 V in V DC Output Voltage Output in 3State 0 5.5 V out High or Low State 0 V CC T Operating Temperature 40 + 85 C A t , t Input Rise and Fall Time V =5.0V 0.5V 0 20 ns/V r f CC Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended Operating Ranges limits may affect device reliability.