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

onsemi MC74ACT240DWG

Name: MC74ACT240DWG
Brand: onsemi
SKU: MC74ACT240DWG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MC74ACT240DWG

Manufacturer:: onsemi

Category:: Buffers, Drivers, Receivers, Transceivers

Package:: 20-SOIC (0.295", 7.50mm Width)

Datasheet:: MC74ACT240DWG.pdf

Description:: IC BUFF INVERT 5.5V 20SOIC

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Product details

Overview

MC74ACT240DWG from onsemi is an octal 3-state buffer/line driver with TTL-compatible inputs, designed for memory address driving, clock distribution, and bidirectional bus interfacing in industrial and embedded systems. It operates at 4.5 V to 5.5 V, delivers ±24 mA output drive, and features 7.0 ns typical propagation delay (tPLH/tPHL) at 5.0 V with 50 pF load.

For engineers reviewing the MC74ACT240DWG datasheet, pinout, applications, or equivalent options, this page provides verified functional specifications, SOIC-20W package details, real-world use cases in bus buffering and address latching, and validated alternative options for design continuity.

Technical Context

The MC74ACT240DWG implements two independent 4-bit groups (pins 12–18 and 3–9), each controlled by separate 3-state enable inputs (OE1 and OE2). Its TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5.5 V) ensure reliable interfacing with legacy 5 V logic families.

Each output supports high-impedance tri-state operation with fast enable/disable timing: tPZH/tPZL ≤ 9.5 ns and tPHZ/tPLZ ≤ 10.5 ns (VCC = 5.0 V, CL = 50 pF). The device meets JEDEC JESD78 latch-up immunity (>±100 mA) and ESD robustness (>2000 V HBM).

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage	4.5 V to 5.5 V - ensures compatibility with standard 5 V TTL and CMOS systems without level-shifting.
Output Drive	±24 mA - sufficient to directly drive multiple 74-series loads or terminate short PCB traces without external buffers.
Propagation Delay	6.0–9.5 ns - enables reliable operation in high-speed address/data buses up to ~100 MHz toggle rate.
3-State Enable Time	7.0–9.5 ns - supports clean bus arbitration in shared-memory or multi-master peripheral interfaces.
Input Thresholds	VIH = 2.0 V, VIL = 0.8 V - guarantees noise margin >0.4 V when driven by standard 5 V TTL outputs.
Quiescent ICC	8.0 µA typical - minimizes standby power in always-on control logic or low-power system management blocks.
Package	SOIC-20W (Case 751D) - industry-standard 0.300" wide body with 1.27 mm pitch, compatible with automated SMT assembly.

Pinout & Package

MC74ACT240DWG uses a 20-pin SOIC-20W (Wide Body) package per Case 751D, with 1.27 mm lead pitch and 7.5 mm body width. Pin 1 is marked by notch or dot; pin numbering follows standard counter-clockwise sequence from top view.

Pin/Terminal	Circuit Role	Design Meaning
1, 20	VCC / GND	Power supply (pin 20) and ground (pin 1) - decoupling capacitor placement near these pins is critical for noise suppression.
12, 14, 16, 18	A1–A4 Inputs / Y1–Y4 Outputs (Group 1)	First 4-bit buffer channel: inputs on even pins, outputs on adjacent odd pins - supports parallel data path segmentation.
3, 5, 7, 9	B1–B4 Inputs / Z1–Z4 Outputs (Group 2)	Second 4-bit buffer channel with independent control - enables dual-bus isolation or split address/data routing.
11, 10	OE1 / OE2	Active-low 3-state enables - OE1 controls pins 12–18; OE2 controls pins 3–9; allows independent bus arbitration.
13	NC	No-connect - internal die pad with no electrical function; must remain unconnected on PCB.

Key Features

Feature	Design Value
TTL-Compatible Inputs	Accepts standard 5 V TTL voltage levels (0.8 V/2.0 V thresholds), eliminating need for level translators in mixed-logic systems.
Independent Dual 4-Bit Enables	OE1 and OE2 allow selective activation of two non-overlapping 4-bit channels - simplifies bus multiplexing without external logic.
High-Drive 3-State Outputs	±24 mA sink/source capability maintains signal integrity across loaded backplanes or long traces while enabling clean bus release.
Pb-Free Construction	RoHS-compliant packaging (marked "G") meets global environmental regulations without performance trade-offs.
Industrial Temperature Range	−40°C to +85°C operation supports deployment in factory automation, motor control, and outdoor embedded equipment.

Applications

Memory Address Buffering	System Clock Distribution
Use Scenario: Driving 16-bit address lines from a microcontroller to multiple SRAM or flash devices on a shared bus. IC Role / Device Role / Timing Role: Bidirectional address latch buffer with 3-state isolation between memory chips during read/write cycles. Use Value: Prevents address bus contention and reduces propagation skew across parallel lines, improving timing margin by ≥1.5 ns vs. direct drive.	Use Scenario: Distributing a master system clock to multiple peripherals (UART, SPI, timers) requiring synchronized timing. IC Role / Device Role / Timing Role: Low-skew clock fanout buffer with matched trace-length support via identical output drive strength. Use Value: Delivers <9.5 ns enable/disable latency and ±24 mA drive to maintain edge integrity across 5+ loads at 50 MHz.
Parallel Data Bus Isolation	Legacy Peripheral Interface
Use Scenario: Isolating a CPU data bus from multiple I/O expanders or ADC/DAC modules sharing the same 8-bit interface. IC Role / Device Role / Timing Role: Direction-controlled 3-state transceiver buffer enabling half-duplex data exchange without bus contention. Use Value: Independent OE1/OE2 control allows dynamic reconfiguration of bus segments, reducing inter-device crosstalk by >15 dB.	Use Scenario: Interfacing modern microcontrollers with legacy 5 V TTL peripherals (e.g., 74LS-series logic, discrete LED drivers). IC Role / Device Role / Timing Role: Level-adaptive buffer translating MCU GPIO outputs to robust TTL-compatible signals. Use Value: TTL input thresholds and ±24 mA drive ensure reliable triggering of LS-family inputs even under 100 mV noise.

Memory Address Buffering

System Clock Distribution

Use Scenario: Driving 16-bit address lines from a microcontroller to multiple SRAM or flash devices on a shared bus.

IC Role / Device Role / Timing Role: Bidirectional address latch buffer with 3-state isolation between memory chips during read/write cycles.

Use Value: Prevents address bus contention and reduces propagation skew across parallel lines, improving timing margin by ≥1.5 ns vs. direct drive.

Use Scenario: Distributing a master system clock to multiple peripherals (UART, SPI, timers) requiring synchronized timing.

IC Role / Device Role / Timing Role: Low-skew clock fanout buffer with matched trace-length support via identical output drive strength.

Use Value: Delivers <9.5 ns enable/disable latency and ±24 mA drive to maintain edge integrity across 5+ loads at 50 MHz.

Parallel Data Bus Isolation

Legacy Peripheral Interface

Use Scenario: Isolating a CPU data bus from multiple I/O expanders or ADC/DAC modules sharing the same 8-bit interface.

IC Role / Device Role / Timing Role: Direction-controlled 3-state transceiver buffer enabling half-duplex data exchange without bus contention.

Use Value: Independent OE1/OE2 control allows dynamic reconfiguration of bus segments, reducing inter-device crosstalk by >15 dB.

Use Scenario: Interfacing modern microcontrollers with legacy 5 V TTL peripherals (e.g., 74LS-series logic, discrete LED drivers).

IC Role / Device Role / Timing Role: Level-adaptive buffer translating MCU GPIO outputs to robust TTL-compatible signals.

Use Value: TTL input thresholds and ±24 mA drive ensure reliable triggering of LS-family inputs even under 100 mV noise.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74ACT240N	Same logic function, TTL-compatible inputs, but PDIP-20 package (not surface-mount); higher thermal resistance (JA = 110°C/W vs. 96°C/W).	Preferred for through-hole prototyping or legacy board rework where SOIC footprint is unavailable.	Select SN74ACT240N only when manual assembly or socket-based testing is required; not suitable for high-density SMT production.
MC74ACT244DWG	Octal non-inverting buffer (vs. inverting MC74ACT240DWG); identical pinout, supply, drive, and timing specs except output polarity.	Required when system logic demands non-inverted signal paths (e.g., transparent data forwarding without complementation).	Choose MC74ACT244DWG if inverting behavior disrupts existing timing or functional flow; otherwise, MC74ACT240DWG remains optimal for address inversion needs.

Compared with SN74ACT240N and MC74ACT244DWG, the MC74ACT240DWG offers superior thermal performance in SMT layouts, native SOIC-20W compatibility for automated manufacturing, and inverting functionality essential for address decoding and bus parity generation - making it the preferred choice for space-constrained industrial controllers.

Availability

MC74ACT240DWG is available at Aetrix Electronics and suitable for memory subsystems, clock distribution networks, and industrial bus interfaces requiring stable component supply, RoHS compliance, and extended temperature operation.

Supply support for MC74ACT240DWG 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 silicon solutions for automotive, industrial, cloud, and IoT applications.

The MC74ACT240DWG belongs to onsemi's 74ACT logic family, engineered for high-speed, low-power 5 V TTL-compatible interfacing in mission-critical industrial control and communications infrastructure.

FAQ

What is the operating voltage range for MC74ACT240DWG?

The MC74ACT240DWG operates over a supply voltage range of 4.5 V to 5.5 V. This narrow window ensures TTL-compatible input thresholds and stable ±24 mA output drive. Operation outside this range risks undefined logic states or degraded timing performance. The MC74ACT240DWG is not rated for 3.3 V operation - use MC74AC240 variants for wider voltage support.

Does MC74ACT240DWG support hot-swap or live-insertion?

No, the MC74ACT240DWG does not include hot-swap protection circuitry. Its absolute maximum ratings specify VCC from −0.5 V to +6.5 V and input/output voltages from −0.5 V to VCC +0.5 V. Applying power or signals before VCC stabilization may cause latch-up or excessive current flow. Always sequence VCC before applying inputs/outputs in MC74ACT240DWG-based systems.

How many independent 3-state control inputs does MC74ACT240DWG have?

The MC74ACT240DWG has two independent active-low 3-state enable inputs: OE1 (pin 11) controls outputs Y1–Y4 (pins 12, 14, 16, 18), and OE2 (pin 10) controls outputs Z1–Z4 (pins 3, 5, 7, 9). This dual-enable architecture allows selective activation of either 4-bit group without affecting the other, enabling flexible bus partitioning in MC74ACT240DWG designs.

Is MC74ACT240DWG pin-compatible with MC74AC240DWG?

Yes, MC74ACT240DWG and MC74AC240DWG share identical SOIC-20W pinouts and package dimensions (Case 751D), but differ electrically: MC74ACT240DWG has TTL-compatible inputs (VIH = 2.0 V), while MC74AC240DWG requires CMOS-level inputs (VIH = 3.15 V at 4.5 V). Swapping them may cause logic misreads unless input source voltage levels are verified for MC74ACT240DWG compatibility.

What is the maximum capacitive load MC74ACT240DWG can drive reliably?

The MC74ACT240DWG AC characteristics are specified at CL = 50 pF, with propagation delays and enable/disable times guaranteed up to that load. While the device can physically drive higher capacitance, timing margins degrade linearly beyond 50 pF - e.g., tPLH increases ~0.15 ns/pF. For loads >75 pF, add series termination or reduce trace length to maintain setup/hold timing in MC74ACT240DWG applications.

MC74ACT240DWG Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74ACT

Package/Case:: 20-SOIC (0.295", 7.50mm Width)

Packaging:: Tube

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:: 24mA, 24mA

Voltage - Supply:: 4.5V ~ 5.5V

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-SOIC

MC74ACT240DWG FAQ

1.How can I place an order for MC74ACT240DWG through Aetrix?

Please submit a Request for Quotation (RFQ) for MC74ACT240DWG 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 MC74ACT240DWG reliable?

The price and inventory of MC74ACT240DWG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC74ACT240DWG is usually 5 days.

3.What payment methods are accepted for MC74ACT240DWG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC74ACT240DWG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MC74ACT240DWG?

MC74ACT240DWG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MC74ACT240DWG 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 MC74ACT240DWG?

For technical support, including MC74ACT240DWG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC74ACT240DWG requirements.

6.How does Aetrix verify that MC74ACT240DWG is sourced from the original manufacturer or authorized distributors?

All MC74ACT240DWG 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 MC74ACT240DWG meets industry standards.

7.What is the process for return or replacement of MC74ACT240DWG?

All MC74ACT240DWG units undergo pre-shipment inspection (PSI). If there is an issue with MC74ACT240DWG, 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 MC74ACT240DWG part is unused and in its original packaging.

Return procedure for MC74ACT240DWG:

1.Submit a request within 90 days.

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

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