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

onsemi MC74AC240DWR2

Name: MC74AC240DWR2
Brand: onsemi
SKU: MC74AC240DWR2
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MC74AC240DWR2

Manufacturer:: onsemi

Category:: Buffers, Drivers, Receivers, Transceivers

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

Datasheet:: MC74AC240DWR2.pdf

Description:: IC BUFF INVERT 6V 20SOIC

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Product details

Overview

MC74AC240DWR2 from onsemi is an octal non-inverting 3-state buffer/line driver used for memory address driving, clock distribution, and bidirectional bus interfacing in high-density PCB designs. It operates from 2.0 V to 6.0 V, delivers ±24 mA output drive, and features TTL-compatible inputs only in the ACT variant - this AC version uses CMOS-compatible thresholds. It supports industrial temperature range (−40°C to +85°C) and is Pb-free.

For engineers reviewing the MC74AC240DWR2 datasheet, pinout, applications, or equivalent options, key selection criteria include supply voltage flexibility (2.0–6.0 V), guaranteed 3-state leakage (<±5.0 µA), propagation delay ≤9.0 ns at 5.0 V, and SOIC-20W package compatibility with standard surface-mount assembly processes.

Technical Context

The MC74AC240DWR2 implements eight independent non-inverting buffers, each with dual 3-state enable controls (OE1 active-low on pins 12/14/16/18; OE2 active-low on pins 3/5/7/9). Its CMOS input structure provides high noise immunity and low static current, while the push-pull output stage ensures rail-to-rail switching with symmetrical sourcing/sinking capability.

It is designed for bus-oriented transmission and reception where bidirectional data flow requires controlled output impedance states. The device meets JEDEC JESD78 latchup immunity (>±100 mA), exceeds 2000 V HBM ESD rating, and maintains stable timing performance across −40°C to +85°C with CL = 50 pF loads.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage Range	2.0 V to 6.0 V - supports mixed-voltage system interfacing without level shifters
Output Drive Strength	±24 mA - sufficient to drive 50-pF loads with <9.0 ns propagation delay at 5.0 V
3-State Leakage Current	<±5.0 µA - ensures minimal bus contention during high-impedance state
Propagation Delay (tPLH/tPHL)	≤7.0 ns max at 5.0 V, CL = 50 pF - enables reliable operation in 100+ MHz bus systems
Input Thresholds (VIH/VIL)	VIH = 2.1 V min, VIL = 0.9 V max at VCC = 3.0 V - CMOS-compatible logic levels, not TTL
Operating Temperature	−40°C to +85°C - qualified for industrial-grade embedded control and instrumentation
Package Type	SOIC-20 Wide Body (Case 751D) - 12.8 mm × 7.5 mm footprint, standard reflow compatible

Pinout & Package

MC74AC240DWR2 is housed in a 20-lead SOIC-Wide (SOIC-20W) package per Case 751D, with 1.27 mm pitch, gull-wing leads, and Pb-free finish. Pin 1 is located at the top-left corner (notch or dot marked), with VCC (pin 20) and GND (pin 10) placed diagonally opposite for optimal decoupling.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 4, 6, 8, 11, 13, 15	Data Inputs (D1–D8)	CMOS-compatible digital inputs; accept 0–VCC logic levels
3, 5, 7, 9	OE2 Group Enable (active-low)	Controls outputs Y1–Y4; low enables, high places in high-Z
12, 14, 16, 18	OE1 Group Enable (active-low)	Controls outputs Y5–Y8; independent of OE2 for split-bus control
19, 20, 17, 16, 14, 13, 11, 9	Outputs (Y1–Y8)	Push-pull buffered outputs; each drives ±24 mA with rail-to-rail swing
10	GND	Ground reference for all I/O and internal circuitry
20	VCC	Primary power supply (2.0–6.0 V); requires local 0.1 µF ceramic decoupling

Key Features

Feature	Design Value
Octal non-inverting buffer architecture	Enables simultaneous buffering of 8-bit address/data buses without signal inversion
Dual independent 3-state enable groups	Allows selective activation of two 4-bit sub-buses (Y1–Y4 and Y5–Y8) for segmented memory access
High-output drive (±24 mA)	Drives multiple TTL or CMOS loads directly - eliminates need for external bus transceivers
Low quiescent ICC (≤80 µA)	Reduces standby power in battery-backed or energy-sensitive applications
Pb-free SOIC-20W packaging	Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity Level 1

Applications

Memory Address Driver	System Clock Buffer
Use Scenario: Driving 8-bit address lines from a microcontroller to SRAM or EPROM chips in compact embedded systems. IC Role / Device Role / Timing Role: Non-inverting buffer with 3-state control isolates MCU address bus during DMA cycles or peripheral access. Use Value: Prevents address bus contention and ensures clean edge integrity over 10+ cm traces at 20 MHz clock rates.	Use Scenario: Distributing a master system clock to multiple peripherals (e.g., ADC, UART, GPIO expanders) on a shared PCB layer. IC Role / Device Role / Timing Role: Low-skew, high-drive clock fanout buffer with independent enable groups for power-gated domains. Use Value: Delivers matched propagation delay (<9 ns) and low jitter to eight destinations, minimizing clock skew across subsystems.
Parallel Bus Transceiver Interface	Industrial I/O Expansion
Use Scenario: Bidirectional 8-bit data bus interface between a host MCU and legacy parallel peripherals (e.g., LCD controllers, printer ports). IC Role / Device Role / Timing Role: Direction-controlled 3-state buffer enabling half-duplex data transfer without dedicated direction lines. Use Value: Dual OE groups allow time-multiplexed read/write arbitration on shared bus lines, reducing MCU pin count.	Use Scenario: Expanding digital I/O capacity in PLC modules or sensor concentrators requiring robust 24 mA drive per line. IC Role / Device Role / Timing Role: High-current buffer stage between FPGA/CPU GPIO and industrial actuators or LED arrays. Use Value: Sustains ±24 mA per channel into 500 Ω loads while maintaining VOL < 0.44 V at 24 mA - suitable for direct LED or relay coil drive.

Memory Address Driver

System Clock Buffer

Use Scenario: Driving 8-bit address lines from a microcontroller to SRAM or EPROM chips in compact embedded systems.

IC Role / Device Role / Timing Role: Non-inverting buffer with 3-state control isolates MCU address bus during DMA cycles or peripheral access.

Use Value: Prevents address bus contention and ensures clean edge integrity over 10+ cm traces at 20 MHz clock rates.

Use Scenario: Distributing a master system clock to multiple peripherals (e.g., ADC, UART, GPIO expanders) on a shared PCB layer.

IC Role / Device Role / Timing Role: Low-skew, high-drive clock fanout buffer with independent enable groups for power-gated domains.

Use Value: Delivers matched propagation delay (<9 ns) and low jitter to eight destinations, minimizing clock skew across subsystems.

Parallel Bus Transceiver Interface

Industrial I/O Expansion

Use Scenario: Bidirectional 8-bit data bus interface between a host MCU and legacy parallel peripherals (e.g., LCD controllers, printer ports).

IC Role / Device Role / Timing Role: Direction-controlled 3-state buffer enabling half-duplex data transfer without dedicated direction lines.

Use Value: Dual OE groups allow time-multiplexed read/write arbitration on shared bus lines, reducing MCU pin count.

Use Scenario: Expanding digital I/O capacity in PLC modules or sensor concentrators requiring robust 24 mA drive per line.

IC Role / Device Role / Timing Role: High-current buffer stage between FPGA/CPU GPIO and industrial actuators or LED arrays.

Use Value: Sustains ±24 mA per channel into 500 Ω loads while maintaining VOL < 0.44 V at 24 mA - suitable for direct LED or relay coil drive.

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
MC74ACT240DWR2G	TTL-compatible inputs (VIH = 2.0 V min at 5 V); otherwise identical pinout, timing, and drive	Required when interfacing with legacy TTL logic families; higher input current vs. AC version	Select when driving from 74LS/74F sources; avoid if system uses pure CMOS logic levels
SN74AC240N	DIP-20 package (not surface-mount); same AC electrical specs but different thermal resistance (JA = 70°C/W vs. 96°C/W)	Suitable for prototyping or through-hole production; lacks Pb-free compliance and tape-and-reel packaging	Prefer for lab validation or low-volume hand-soldered builds; not recommended for automated SMT lines

Compared with MC74AC240DWR2, MC74ACT240DWR2G offers TTL input compatibility at the cost of slightly higher input current, while SN74AC240N provides identical AC functionality in through-hole form - neither is pin-compatible in package or thermal profile, making MC74AC240DWR2 the optimal choice for Pb-free, high-density SOIC-based industrial designs.

Availability

MC74AC240DWR2 is available at Aetrix Electronics and suitable for memory address driving, clock distribution, and industrial I/O expansion requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MC74AC240DWR2 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 computing, and IoT applications.

The MC74AC240DWR2 belongs to onsemi's 74AC logic family - designed for high-speed, low-power, mixed-voltage digital interfacing in space-constrained industrial and communications equipment.

FAQ

What is the maximum operating supply voltage for MC74AC240DWR2?

The MC74AC240DWR2 supports a DC supply voltage range of −0.5 V to +6.5 V, with recommended operation from 2.0 V to 6.0 V. Exceeding 6.5 V risks permanent damage per Absolute Maximum Ratings. At 6.0 V, VOH remains ≥5.4 V and VOL ≤0.44 V under 24 mA load - verified across −40°C to +85°C.

Does MC74AC240DWR2 have TTL-compatible inputs?

No, MC74AC240DWR2 does not have TTL-compatible inputs. Its VIH minimum is 2.1 V at VCC = 3.0 V and 3.85 V at VCC = 5.5 V - consistent with CMOS thresholds. For TTL compatibility, use MC74ACT240DWR2G, which specifies VIH = 2.0 V min across 4.5–5.5 V.

What is the 3-state enable behavior of MC74AC240DWR2?

MC74AC240DWR2 has two independent active-low 3-state enable groups: OE1 (pins 12/14/16/18) controls outputs Y5–Y8, and OE2 (pins 3/5/7/9) controls Y1–Y4. When either OE is high, its associated outputs enter high-impedance state regardless of input state - confirmed by truth table and DC leakage spec (IOZ < ±5.0 µA).

Can MC74AC240DWR2 drive a 50-pF load within 10 ns propagation delay?

Yes. At VCC = 5.0 V and CL = 50 pF, MC74AC240DWR2 guarantees tPLH/tPHL ≤7.0 ns (max) over temperature, well within 10 ns. This is validated in AC Characteristics Table on page 4 of the datasheet and applies to all eight channels under worst-case conditions.

Is MC74AC240DWR2 RoHS-compliant and Pb-free?

Yes. MC74AC240DWR2 is explicitly marked as a Pb-free device in the datasheet (page 1, Features section and Ordering Information on page 6). The "G" suffix in MC74AC240DWR2G confirms RoHS compliance per EU Directive 2011/65/EU and JESD97 standards.

MC74AC240DWR2 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74AC

Package/Case:: 20-SOIC (0.295", 7.50mm 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:: 24mA, 24mA

Voltage - Supply:: 2V ~ 6V

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-SOIC

MC74AC240DWR2 FAQ

1.How can I place an order for MC74AC240DWR2 through Aetrix?

Please submit a Request for Quotation (RFQ) for MC74AC240DWR2 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 MC74AC240DWR2 reliable?

The price and inventory of MC74AC240DWR2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC74AC240DWR2 is usually 5 days.

3.What payment methods are accepted for MC74AC240DWR2?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC74AC240DWR2 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MC74AC240DWR2?

MC74AC240DWR2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MC74AC240DWR2 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 MC74AC240DWR2?

For technical support, including MC74AC240DWR2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC74AC240DWR2 requirements.

6.How does Aetrix verify that MC74AC240DWR2 is sourced from the original manufacturer or authorized distributors?

All MC74AC240DWR2 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 MC74AC240DWR2 meets industry standards.

7.What is the process for return or replacement of MC74AC240DWR2?

All MC74AC240DWR2 units undergo pre-shipment inspection (PSI). If there is an issue with MC74AC240DWR2, 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 MC74AC240DWR2 part is unused and in its original packaging.

Return procedure for MC74AC240DWR2:

1.Submit a request within 90 days.

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

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