MC74VHCT541A Octal Bus Buffer The MC74VHCT541A 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 maintaining CMOS low power dissipation. The MC74VHCT541A is a noninverting, 3 state, buffer/line MC74VHCT541A 2 18 A1 Y1 3 17 A2 Y2 OE1 1 20 V CC 4 16 A3 Y3 A1 2 19 OE2 A2 3 18 Y1 5 15 A4 Y4 DATA NONINVERTING A3 4 17 Y2 INPUTS OUTPUTS 6 14 A4 5 16 Y3 A5 Y5 A5 6 15 Y4 7 13 A6 Y6 A6 7 14 Y5 8 12 A7 8 13 Y6 A7 Y7 A8 9 12 Y7 9 11 A8 Y8 GND 10 11 Y8 1 OE1 Figure 2. Pin Assignment OUTPUT ENABLES 19 OE2 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 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 out voltage higher than maximum rated High or Low State 0.5 to V + 0.5 CC voltages to this highimpedance cir- I Input Diode Current 20 mA IK cuit. For proper operation, V and in 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 I DC Output Current, per Pin 25 mA Unused inputs must always be 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 Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied, damage may occur and reliability may be affected. Derating SOIC Packages: 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 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