onsemi MM74HC240WM

Overview

MM74HC240WM from onsemi is an inverting octal 3-STATE buffer IC with two independent active-low enables (1G, 2G), each controlling four buffers. It operates across 2–6 V supply, delivers 6 mA output drive, exhibits 12 ns typical propagation delay, and supports high-noise-immunity bus interfacing in industrial control backplanes.

For engineers reviewing the MM74HC240WM datasheet, pinout, applications, or equivalent options, key selection criteria include its dual enable architecture, SOIC-20 WB package, guaranteed 3-STATE leakage < ±5 µA at 6 V, −55°C to +125°C operating range, and compatibility with LS-TTL fanout (15 loads).

Technical Context

The MM74HC240WM implements eight independent inverting buffers, partitioned into two groups of four (1A1–1A4 / 1Y1–1Y4 and 2A1–2A4 / 2Y1–2Y4), each gated by separate active-low enables (1G, 2G). Its CMOS silicon-gate design ensures rail-to-rail input thresholds and symmetrical output drive capability.

Each buffer provides true 3-STATE (high-impedance) outputs when its respective enable is HIGH, enabling bidirectional bus sharing without external logic. Input protection diodes clamp to VCC and GND, supporting ESD robustness per JEDEC JS-001 Class 2 (±2 kV HBM).

Key Specifications

Pinout & Package

MM74HC240WM is housed in a Pb-free SOIC-20 WB (Wide Body) package (Case 751D-05), 12.95 mm × 7.60 mm × 2.65 mm, with 1.27 mm pitch and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inverting octal 3-STATE buffer applications.

Compared with SN74HC240N and 74VHC240M, the MM74HC240WM offers the widest temperature range (−55°C to +125°C) and lowest high-temp ICC (160 µA), making it optimal for mission-critical embedded systems where thermal resilience and low standby power are prioritized over raw speed.

Availability

MM74HC240WM is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive ECU signal conditioning, and test equipment digital pattern generation requiring stable component supply, long-term lifecycle support, and traceable Pb-free sourcing.

Supply support for MM74HC240WM 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 focused on energy-efficient innovation for automotive, industrial, cloud, medical, and IoT applications.

The MM74HC240WM belongs to onsemi's legacy HC logic family, designed specifically for robust, low-power bus interfacing in harsh-environment embedded systems requiring extended temperature operation and high noise immunity.

FAQ

What is the maximum operating temperature range for the MM74HC240WM?

The MM74HC240WM is specified for continuous operation from −55°C to +125°C. This extended temperature range is validated per onsemi's qualification standards and makes the MM74HC240WM suitable for under-hood automotive, industrial control, and aerospace applications where ambient temperatures exceed standard commercial limits. The MM74HC240WM maintains full DC and AC performance across this entire range, including guaranteed 3-STATE leakage and propagation delay specs.

Does the MM74HC240WM support 3.3 V logic systems?

Yes, the MM74HC240WM supports 3.3 V logic systems. Its supply voltage range is 2–6 V, and all electrical characteristics-including VIH (≥1.5 V at VCC = 2 V), VOL (≤0.26 V at VCC = 4.5 V, IO = 6 mA), and propagation delay (20 ns max at VCC = 3.3 V, CL = 50 pF)-are fully specified down to 2 V. This ensures interoperability with 3.3 V microcontrollers and FPGAs without level translation.

How many independent enable controls does the MM74HC240WM have?

The MM74HC240WM has two independent active-LOW enable inputs: 1G controls buffers 1Y1–1Y4, and 2G controls buffers 2Y1–2Y4. Each enable operates independently, allowing selective activation of either four-buffer group while the other remains in high-impedance state. This architecture enables flexible bus partitioning and reduces contention in multi-master systems-key functionality confirmed in the MM74HC240WM truth table and logic diagram.

Is the MM74HC240WM pin-compatible with the SN74HC240N?

Yes, the MM74HC240WM is pin-compatible with the SN74HC240N in the SOIC-20 package. Both share identical pin assignments, logic function, and electrical interface. However, the MM74HC240WM extends the operating temperature range to −55°C to +125°C and specifies lower quiescent current (160 µA vs. 200 µA max), while the SN74HC240N is limited to −40°C to +85°C. No PCB changes are required for substitution where temperature and power requirements align.

What is the typical propagation delay of the MM74HC240WM at 5 V operation?

The typical propagation delay of the MM74HC240WM is 12 ns at VCC = 4.5 V, CL = 50 pF, and TA = 25°C. At nominal 5 V operation (VCC = 5.0 V), the datasheet guarantees ≤20 ns maximum tPLH/tPHL under the same load conditions. This value reflects worst-case delay across process, voltage, and temperature corners and is measured between 50% input transition and 50% output transition points-critical for timing budget validation in the MM74HC240WM's target applications.