onsemi MC74LVX245M

Overview

MC74LVX245M from onsemi is an advanced high-speed CMOS octal bus transceiver with 5 V-tolerant inputs, designed for bidirectional asynchronous data bus communication between 3.3 V and 5 V domains. It features direction control via T/R input, 3-state output enable (OE), 4.7 ns typical propagation delay at 3.3 V, ±25 mA output drive per pin, and operates from −40 °C to +85 °C.

For engineers reviewing the MC74LVX245M datasheet, pinout, applications, or equivalent options, key selection criteria include 5 V-tolerant input compatibility, bidirectional bus isolation capability, SOIC-20W package footprint, and low-noise 3.3 V logic-level translation in mixed-voltage systems.

Technical Context

The MC74LVX245M implements a non-inverting dual-bus transceiver architecture with independent OE and T/R control signals. Its 5 V-tolerant inputs allow direct connection to 5 V buses without level-shifting, while outputs swing rail-to-rail within the 2.0–3.6 V VCC range. Propagation delays are balanced across all eight channels (tPLH/tPHL ≤ 11.5 ns max at 3.3 V, CL = 50 pF).

It supports true 3-state operation with <±2.5 µA high-impedance leakage (IOZ) and includes ESD protection >2000 V HBM. The device avoids internal parasitic conduction paths that would compromise 5 V ↔ 3 V interfacing - a critical design constraint explicitly noted in its application notes.

Key Specifications

Pinout & Package

MC74LVX245M is supplied in a 20-pin SOIC-20 WB (Case 751D) package with standard 1.27 mm pitch, 12.8 mm × 7.5 mm body size, and Pb-free (RoHS-compliant) finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal bus transceiver applications.

Compared with SN74LVC245APWR and 74ALVC245MTCX, the MC74LVX245M delivers superior thermal robustness (+85 °C rating), tighter VOL specification (0.44 V vs. 0.55 V), and proven latchup immunity (>100 mA), making it the preferred choice for industrial and automotive bus isolation where reliability outweighs marginal speed gains.

Availability

MC74LVX245M is available at Aetrix Electronics and suitable for industrial PLC backplane interfaces, embedded microcontroller expansion buses, and automotive body control modules requiring stable component supply across long production lifecycles.

Supply support for MC74LVX245M includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power and signal management solutions, with leadership in automotive, industrial, cloud computing, and IoT markets.

The MC74LVX245M belongs to onsemi's LVX low-voltage logic family, engineered for robust 3.3 V operation with 5 V-tolerant inputs to simplify mixed-voltage system integration in industrial control and communications infrastructure.

FAQ

What is the maximum allowable input voltage on MC74LVX245M pins?

The MC74LVX245M supports DC input voltages from −0.5 V to +6.5 V on all pins, including T/R and OE. This 5 V-tolerant capability allows direct connection to 5 V buses while operating from a 3.3 V supply, eliminating external level-shifting components. Exceeding +6.5 V risks permanent damage per the Absolute Maximum Ratings table.

Can MC74LVX245M be used to interface 5 V and 3 V systems directly?

No - although MC74LVX245M accepts 5 V inputs, its outputs swing only between GND and VCC (2.0–3.6 V). A parasitic diode exists between B-side I/O and VCC, preventing safe 5 V output driving. Therefore, MC74LVX245M is strictly for 5 V → 3.3 V input translation, not bidirectional voltage conversion. External clamping or level-shifting is required for 3 V → 5 V output paths.

What is the propagation delay specification for MC74LVX245M at 3.3 V?

The MC74LVX245M has a typical propagation delay (tPLH/tPHL) of 4.7 ns at VCC = 3.3 V with CL = 15 pF, and a maximum of 11.5 ns under worst-case conditions (TA = −40 °C to +85 °C, CL = 50 pF). This delay is guaranteed across all eight channels with ≤1.5 ns skew, ensuring deterministic timing in parallel data paths.

Does MC74LVX245M require pull-up or pull-down resistors on unused inputs?

Yes - all floating (high-impedance) inputs or I/O pins on the MC74LVX245M must be fixed using pull-up or pull-down resistors or bus terminator ICs. Floating inputs can cause excessive ICC, unpredictable logic states, or increased EMI. The datasheet explicitly warns against leaving T/R or OE unconnected, as this may result in undefined transceiver behavior or bus contention.

What package type is used for MC74LVX245M and what are its key mechanical dimensions?

MC74LVX245M uses the SOIC-20 WB (Wide Body) package, designated Case 751D, with 1.27 mm pitch, 12.8 mm × 7.5 mm body size, and 2.5 mm height. It features Pb-free (RoHS-compliant) finish and moisture sensitivity level (MSL) 3, requiring bake conditioning before reflow if exposed beyond floor life. The package is optimized for automated assembly and thermal dissipation in industrial PCB layouts.