MC74VHCT245ADTG ON Semiconductor

MC74VHCT245A Octal Bus Transceiver The MC74VHCT245A is an advanced high speed CMOS octal bus transceiver fabricated with silicon gate CMOS technology. It achieves high speed operation similar to equivalent Bipolar Schottky TTL while maintaining CMOS low power dissipation. It is intended for twoway asynchronous communication between MC74VHCT245A 2 18 A1 B1 3 17 A2 B2 4 16 DIR 1 20 V CC A3 B3 5 15 A B A4 B4 A1 2 19 OE DATA DATA 6 14 A5 B5 A2 3 18 B1 PORT PORT 7 13 A6 B6 A3 4 17 B2 8 12 A7 B7 A4 5 16 B3 9 11 A8 B8 A5 6 15 B4 1 A6 7 14 B5 DIR 19 A7 8 13 B6 OE Figure 1. Logic Diagram A8 9 12 B7 GND 10 11 B8 FUNCTION TABLE Figure 2. Pin Assignment Control Inputs OE DIR Operation L L Data Tx from Bus B to Bus A L H Data Tx from Bus A to Bus B H X Buses Isolated (HighZ State) 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 in fields. However, precautions must be taken to avoid applications of any V DC Output Voltage Outputs in 3State 0.5 to + 7.0 V I/O 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 Outputs in 3State 0 5.5 V I/O 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.