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Home > Products > Integrated Circuits (ICs) > Logic > Buffers, Drivers, Receivers, Transceivers

onsemi MM74HC240SJX

Name: MM74HC240SJX
Brand: onsemi
SKU: MM74HC240SJX
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MM74HC240SJX

Manufacturer:: onsemi

Category:: Buffers, Drivers, Receivers, Transceivers

Package:: 20-SOIC (0.209", 5.30mm Width)

Datasheet:: MM74HC240SJX.pdf

Description:: IC BUFFER INVERT 6V 20SOP

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Product details

Overview

MM74HC240SJX from onsemi is an inverting octal 3-STATE buffer IC with two independent active-low enables (1G, 2G), operating across 2–6 V supply, delivering 6 mA output drive and 12 ns typical propagation delay at 4.5 V - used for bidirectional bus interfacing in industrial control backplanes.

For engineers reviewing the MM74HC240SJX datasheet, pinout, applications, or equivalent options, key selection criteria include its dual enable architecture, 3-STATE output compatibility with TTL/CMOS buses, wide temperature range (−55°C to +125°C), and Pb-free SOIC-20 WB package compliance.

Technical Context

The MM74HC240SJX implements eight inverting buffers partitioned into two groups of four, each controlled by a dedicated active-low enable (1G for Y1–Y4, 2G for Y5–Y8). All inputs feature diode-based ESD protection to V_CC and GND.

It operates under CMOS logic thresholds (V_IL ≤ 1.35 V, V_IH ≥ 3.15 V at V_CC = 4.5 V), supports dynamic loading up to 150 pF, and maintains guaranteed 3-STATE leakage (±10 µA) and quiescent current (160 µA max) over full temperature range.

Key Specifications

Parameter	Value and Actual Design Meaning
Logic Function	Inverting octal buffer with dual active-low enables (1G, 2G)
Supply Voltage Range	2–6 V - supports mixed-voltage system interfacing (e.g., 3.3 V microcontrollers driving 5 V peripherals)
Propagation Delay	12 ns typical at V_CC = 4.5 V, CL = 50 pF - enables reliable operation in 20 MHz+ bus systems
Output Drive	±6 mA at V_CC = 4.5 V - sufficient to drive 15 LS-TTL loads or moderate PCB trace capacitance
Operating Temperature	−55°C to +125°C - qualified for extended industrial and automotive under-hood environments
3-STATE Leakage	±10 µA max at V_CC = 6 V, −55°C ≤ T_A ≤ 125°C - ensures minimal bus contention during high-impedance state
Input Capacitance	10 pF max - limits switching noise and reduces loading on upstream drivers

Pinout & Package

MM74HC240SJX is packaged in Pb-free SOIC-20 WB (Case 751D-05), 12.8 mm × 7.5 mm body, 1.27 mm pitch, 2.5 mm height.

Pin/Terminal	Circuit Role	Design Meaning
1G	Group 1 Enable (active low)	Controls 1Y1–1Y4 outputs; pulls all four to high-Z when HIGH
1A1–1A4	Group 1 Inputs	Invert and buffer to corresponding 1Y outputs when 1G = LOW
1Y1–1Y4	Group 1 Inverted Outputs	Active only when 1G = LOW; otherwise high-impedance
2G	Group 2 Enable (active low)	Controls 2Y1–2Y4 outputs; independent of 1G
2A1–2A4	Group 2 Inputs	Invert and buffer to corresponding 2Y outputs when 2G = LOW
2Y1–2Y4	Group 2 Inverted Outputs	Active only when 2G = LOW; otherwise high-impedance
V_CC	Positive Supply	Power rail for all logic and output stages; decoupling required near pin 20
GND	Ground Reference	Return path for supply and signal currents; connect to low-impedance ground plane

Key Features

Feature	Design Value
Dual independent enables	Allows selective activation of two 4-bit data paths without external gating logic
High noise immunity	CMOS input thresholds (V_IH/V_IL) provide >40% V_CC noise margin at 5 V operation
Low power consumption	160 µA max ICC enables battery-backed or energy-constrained industrial monitoring nodes
Pb-free SOIC-20 WB	RoHS-compliant footprint compatible with standard reflow profiles and automated assembly
ESD-protected inputs	Diode clamps to V_CC and GND withstand ±2 kV HBM - reduces need for external TVS on control lines

Applications

Industrial PLC Backplane Interface	Automotive Body Control Module I/O Expansion
Use Scenario: Isolating and buffering address/data lines between CPU and peripheral modules in modular programmable logic controllers. IC Role / Device Role / Timing Role: Inverting 3-STATE buffer providing direction-controlled bus access with dual enable for read/write channel separation. Use Value: Enables clean signal integrity across 20 cm backplane traces while supporting hot-swap capability via controlled high-Z states.	Use Scenario: Expanding GPIO count for door lock, window lift, and lighting control in centralized body electronics units. IC Role / Device Role / Timing Role: Level-shifting and bus-driving interface between 3.3 V MCU and 5 V actuator drivers with ESD-hardened inputs. Use Value: Eliminates discrete level translators and reduces BOM count while meeting ISO 10605 ESD requirements without added protection components.
Test Equipment Digital Pattern Generator	Medical Diagnostic Data Acquisition Interface
Use Scenario: Driving parallel stimulus patterns to DUTs in automated test systems requiring precise timing and low skew. IC Role / Device Role / Timing Role: Synchronized inverting buffer with matched t_PHL/t_PLH (≤18 ns max) for deterministic edge alignment across 8 channels. Use Value: Delivers sub-20 ns channel-to-channel skew at 10 MHz, enabling accurate timing margin validation for digital ASICs.	Use Scenario: Interfacing ADC output buses to FPGA-based signal processors in portable ultrasound and ECG devices. IC Role / Device Role / Timing Role: Bidirectional bus isolator with 3-STATE control synchronized to FPGA read cycles to prevent data bus contention. Use Value: Supports 12-bit parallel ADC throughput up to 2 MSPS while maintaining <100 µW static power per channel.

Industrial PLC Backplane Interface

Automotive Body Control Module I/O Expansion

Use Scenario: Isolating and buffering address/data lines between CPU and peripheral modules in modular programmable logic controllers.

IC Role / Device Role / Timing Role: Inverting 3-STATE buffer providing direction-controlled bus access with dual enable for read/write channel separation.

Use Value: Enables clean signal integrity across 20 cm backplane traces while supporting hot-swap capability via controlled high-Z states.

Use Scenario: Expanding GPIO count for door lock, window lift, and lighting control in centralized body electronics units.

IC Role / Device Role / Timing Role: Level-shifting and bus-driving interface between 3.3 V MCU and 5 V actuator drivers with ESD-hardened inputs.

Use Value: Eliminates discrete level translators and reduces BOM count while meeting ISO 10605 ESD requirements without added protection components.

Test Equipment Digital Pattern Generator

Medical Diagnostic Data Acquisition Interface

Use Scenario: Driving parallel stimulus patterns to DUTs in automated test systems requiring precise timing and low skew.

IC Role / Device Role / Timing Role: Synchronized inverting buffer with matched t_PHL/t_PLH (≤18 ns max) for deterministic edge alignment across 8 channels.

Use Value: Delivers sub-20 ns channel-to-channel skew at 10 MHz, enabling accurate timing margin validation for digital ASICs.

Use Scenario: Interfacing ADC output buses to FPGA-based signal processors in portable ultrasound and ECG devices.

IC Role / Device Role / Timing Role: Bidirectional bus isolator with 3-STATE control synchronized to FPGA read cycles to prevent data bus contention.

Use Value: Supports 12-bit parallel ADC throughput up to 2 MSPS while maintaining <100 µW static power per channel.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74HC240N	Same logic function, identical AC/DC specs, but offered in legacy PDIP-20 (not Pb-free); no TSSOP option	Preferred for through-hole prototyping or legacy repair; lacks SOIC-20 WB thermal performance	Select SN74HC240N only if DIP socketing or hand-soldering is required; not recommended for new SMT designs.
74LVX240M	Lower V_CC range (2.0–3.6 V), higher speed (7.5 ns typ), but incompatible with 5 V buses and lacks −55°C rating	Suitable for 3.3 V-only portable medical devices; cannot replace MM74HC240SJX in mixed-voltage industrial systems	Choose 74LVX240M only for battery-powered 3.3 V systems where 5 V tolerance and extended temperature are unnecessary.

Compared with SN74HC240N and 74LVX240M, the MM74HC240SJX uniquely combines Pb-free SOIC-20 WB packaging, full −55°C to +125°C qualification, and 2–6 V operation - making it the only option qualified for new industrial automation designs requiring RoHS compliance and wide temperature resilience.

Availability

MM74HC240SJX is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive body control modules, and medical diagnostic interfaces requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MM74HC240SJX 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 is a global semiconductor manufacturer specializing in energy-efficient, high-reliability silicon solutions for automotive, industrial, cloud, and medical applications.

The MM74HC240SJX belongs to onsemi's HC logic family, designed specifically for robust, low-power bus interface and signal conditioning in harsh-environment embedded systems.

FAQ

What is the maximum clock frequency supported by the MM74HC240SJX?

The MM74HC240SJX does not operate as a clocked device but as a combinatorial buffer. Its propagation delay (12 ns typical at 4.5 V) supports reliable data transfer in asynchronous bus systems up to ~20 MHz. For synchronous timing-critical applications, system-level setup/hold margins must be validated using worst-case t_PHL/t_PLH (18 ns) and load conditions per the MM74HC240SJX datasheet.

Does the MM74HC240SJX support 5 V TTL input compatibility?

Yes, the MM74HC240SJX supports 5 V TTL input levels: its V_IH (min 3.15 V at V_CC = 4.5 V) and V_IL (max 1.35 V) meet standard TTL thresholds, allowing direct connection to 5 V TTL outputs without level shifting. This is confirmed in the DC Electrical Characteristics table of the MM74HC240SJX datasheet.

What is the thermal resistance (θ_JA) of the MM74HC240SJX in SOIC-20 WB package?

The MM74HC240SJX in SOIC-20 WB (Case 751D-05) has a junction-to-ambient thermal resistance (θ_JA) of 90°C/W, derived from its 1302 mW power dissipation rating and 2.5 mm package height. This value assumes standard JEDEC 2-layer board layout; actual θ_JA improves with copper pour and thermal vias per the MM74HC240SJX package dimensions document.

Can both enables (1G and 2G) be tied together for single-group operation?

Yes, 1G and 2G can be connected to a common control signal to operate all eight buffers as a single group. This configuration is electrically valid and used in applications like simple bus transceivers. However, doing so forfeits the independent group control capability inherent to the MM74HC240SJX design - a key differentiator versus single-enable octal buffers.

Is the MM74HC240SJX pinout compatible with the MM74HC244SJX?

No, the MM74HC240SJX is not pin-compatible with the MM74HC244SJX. While both are octal buffers in SOIC-20 WB, the MM74HC240SJX is inverting with dual active-low enables, whereas the MM74HC244SJX is non-inverting with dual active-high enables. Their pin assignments differ: MM74HC240SJX places 1G at pin 1 and 2G at pin 19, while MM74HC244SJX places 1OE at pin 1 and 2OE at pin 19 - requiring PCB redesign for substitution.

MM74HC240SJX Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74HC

Package/Case:: 20-SOIC (0.209", 5.30mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Logic Type:: Buffer, Inverting

Number of Elements:: 2

Number of Bits per Element:: 4

Input Type:: -

Output Type:: 3-State

Current - Output High, Low:: 7.8mA, 7.8mA

Voltage - Supply:: 2V ~ 6V

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-SOP

MM74HC240SJX FAQ

1.How can I place an order for MM74HC240SJX through Aetrix?

Please submit a Request for Quotation (RFQ) for MM74HC240SJX on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for MM74HC240SJX reliable?

The price and inventory of MM74HC240SJX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MM74HC240SJX is usually 5 days.

3.What payment methods are accepted for MM74HC240SJX?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MM74HC240SJX transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MM74HC240SJX?

MM74HC240SJX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MM74HC240SJX order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for MM74HC240SJX?

For technical support, including MM74HC240SJX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MM74HC240SJX requirements.

6.How does Aetrix verify that MM74HC240SJX is sourced from the original manufacturer or authorized distributors?

All MM74HC240SJX products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MM74HC240SJX meets industry standards.

7.What is the process for return or replacement of MM74HC240SJX?

All MM74HC240SJX units undergo pre-shipment inspection (PSI). If there is an issue with MM74HC240SJX, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The MM74HC240SJX part is unused and in its original packaging.

Return procedure for MM74HC240SJX:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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