MC74LVX245MG

Overview

The MC74LVX245MG is an advanced high-speed CMOS octal bus transceiver manufactured by onsemi. It facilitates two-way asynchronous communication between data buses, with transmission direction controlled by the T/R input and device enablement managed by the OE pin. The component operates within a DC supply voltage range of 2.0 V to 3.6 V and supports inputs up to 5.5 V. Key electrical parameters include a typical propagation delay (tPD) of 4.7 ns at 3.3 V, a maximum quiescent supply current (ICC) of 40 µA, and a low noise dynamic VOL of 0.8 V max. It features balanced propagation delays and provides power-down protection on inputs.

Feature Summary

• Provides bidirectional asynchronous communication between data buses via dedicated Transmit/Receive and Output Enable control pins.
• Features 5 V-tolerant inputs allowing safe interfacing with higher voltage logic levels while operating at lower supply voltages.
• Includes robust protection circuits against static discharge and latchup performance exceeding 100 mA.
• Delivers balanced propagation delays and low noise characteristics for reliable signal integrity.

Applications

• Two-way asynchronous communication between data buses
• Memory bus interfaces requiring 5 V tolerant I/O capabilities
• High-speed data transfer applications in consumer electronics

Procurement Notes

Verify the specific package suffix 'MG' corresponds to the SOIC-20 or TSSOP-20 configuration required for your design, as ordering information lists variants like DWR2G and DTR2G. Confirm RoHS compliance and Pb-Free status through official manufacturer documentation before finalizing procurement. Ensure all floating inputs are properly terminated to prevent undefined states.

Selection Notes

Select this component when designing systems requiring octal bus transceivers with 5 V tolerance and low power consumption. Verify that the operating temperature range of -40°C to +85°C meets environmental requirements. Consider the 2.0 V to 3.6 V supply voltage constraints and ensure the load capacitance does not exceed specifications to maintain the stated propagation delay performance.

Part Context

This device belongs to the 74LVX series of advanced high-speed CMOS logic products from onsemi. It is functionally compatible with other standard logic families, simplifying integration into existing designs. The LVX series is characterized by its ability to operate at lower voltages while maintaining high speed and offering improved noise immunity compared to older logic standards.

Replacement Considerations

Direct substitutes include the MC74LVX245DTR2G (TSSOP-20) and MC74LVX245DWR2G (SOIC-20). These variants share identical electrical characteristics and pinouts but differ in packaging and shipping quantities. Verify package dimensions and marking diagrams to ensure mechanical compatibility.

FAQ

Can the MC74LVX245MG be used to directly interface 5.0 V systems to 3.0 V systems?

No. A parasitic diode is formed between the bus and VCC terminals, preventing direct interfacing between 5.0 V and 3.0 V systems without additional circuitry.

What happens if inputs are left floating?

All floating (high impedance) input or I/O pins must be fixed by means of pullup or pulldown resistors or bus terminator ICs to ensure proper operation and prevent damage.

How is the direction of data transmission determined?

The direction is determined by the level of the T/R input: Low enables B-to-A transmission, High enables A-to-B transmission, and High-Z disables the outputs.