Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

onsemi MC74VHCT240AMELG

Name: MC74VHCT240AMELG
Brand: onsemi
SKU: MC74VHCT240AMELG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: MC74VHCT240AMELG

Manufacturer:: onsemi

Category:: Buffers, Drivers, Receivers, Transceivers

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

Datasheet:: MC74VHCT240AMELG.pdf

Description:: IC BUFFER INVERT 5.5V SOEIAJ-20

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,114

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

MC74VHCT240AMELG from onsemi is an octal inverting buffer/line driver with 3-state outputs, designed for TTL-level input compatibility and CMOS-level output drive. It operates from 4.5 V to 5.5 V, features ±8 mA output drive, 7.5 ns typical propagation delay at V_CC = 5 V, and supports bus-oriented applications requiring bidirectional data flow control.

For engineers reviewing the MC74VHCT240AMELG datasheet, pinout, applications, or equivalent options, key selection criteria include input threshold compatibility with 5 V TTL logic, guaranteed 3-state isolation during power-down, rail-to-rail output swing, and industrial temperature range operation (–40 °C to +85 °C).

Technical Context

This device implements two independent 4-bit inverting buffers, each with active-low output-enable (OE) control. All inputs are TTL-compatible (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V), while outputs swing fully to V_CC or GND with CMOS drive strength.

The 3-state outputs exhibit high-impedance off-state leakage < ±10 µA at 25 °C and support hot-insertion when OE is held inactive. Propagation delays are balanced across rising/falling edges (t_PLH ≈ t_PHL ≈ 7.5 ns), minimizing skew in synchronous bus interfaces.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage	4.5 V to 5.5 V - Ensures robust operation across standard 5 V rail tolerances and brown-out conditions.
Input Logic Threshold	V_IL ≤ 0.8 V, V_IH ≥ 2.0 V - Guarantees reliable recognition of legacy TTL signal levels.
Output Drive Strength	±8 mA at V_CC = 5 V - Supports driving 15 pF loads with full logic swing and minimal rise/fall time degradation.
Propagation Delay	7.5 ns max (typical) - Enables use in 100 MHz bus clock domains with sufficient timing margin.
Operating Temperature	–40 °C to +85 °C - Qualified for industrial-grade embedded control and instrumentation environments.
3-State Leakage	±10 µA max - Prevents signal contention and bus corruption when outputs are disabled.

Pinout & Package

MC74VHCT240AMELG is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package with 0.300-inch body width and standard JEDEC MS-013AC footprint.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 4, 5, 9, 10, 12, 13	Input (A1–A8)	TTL-compatible digital inputs accepting 0–5 V logic signals; internally pulled down via 10 kΩ resistors in some variants but not specified for this part.
3, 6, 7, 8, 11, 14, 15, 16	Inverted Output (Y1–Y8)	CMOS-level buffered outputs with active-low inversion; high-impedance when OE asserted low.
17, 18	Output Enable (OE1, OE2)	Active-low enables for respective 4-bit sections; both must be low to activate outputs.
10, 20	GND / V_CC	Ground reference and 5 V supply pins; decoupling capacitor placement critical near Pin 20 for noise immunity.

Key Features

Feature	Design Value
TTL-Compatible Inputs	Accepts standard 5 V TTL logic thresholds without level-shifting circuitry, simplifying integration with legacy controllers.
CMOS Output Drive	Delivers ±8 mA sink/source current enabling direct interface to multiple CMOS loads or transmission lines up to 15 pF.
Independent 3-State Control	Dual OE pins allow selective disabling of upper/lower 4-bit groups, supporting partial bus arbitration and memory-mapped I/O partitioning.
Low Propagation Skew	Matched t_PLH/t_PHL ensures symmetrical edge timing critical for synchronous data capture in microcontroller peripheral buses.

Applications

Microcontroller Bus Interface	Industrial I/O Expansion
Use Scenario: Interfacing an 8-bit microcontroller data bus to external peripherals with mismatched voltage or drive requirements. IC Role / Device Role / Timing Role: Bidirectional buffer providing level translation, fanout amplification, and bus isolation during wait states. Use Value: Eliminates need for discrete level shifters and reduces PCB area by consolidating eight channels in one SOIC-20 package.	Use Scenario: Adding parallel digital I/O capability to PLC modules or sensor concentrators operating in noisy factory environments. IC Role / Device Role / Timing Role: Inverting line driver isolating field-side logic from controller-side logic while maintaining signal integrity. Use Value: ±8 mA drive sustains signal margins over longer traces; 3-state control enables dynamic bus sharing among multiple expansion cards.
Memory Address Latching	Test Equipment Signal Conditioning
Use Scenario: Driving address lines to SRAM or EPROM devices where inverted addressing is required or tolerated. IC Role / Device Role / Timing Role: Inverting buffer with precise propagation delay used in address decode path to meet setup/hold timing windows. Use Value: 7.5 ns delay is predictable and stable across temperature, enabling deterministic timing budget allocation in memory subsystems.	Use Scenario: Conditioning digital stimulus/response signals in automated test equipment (ATE) channel cards. IC Role / Device Role / Timing Role: Signal conditioner providing gain, inversion, and bus isolation between DUT interface and FPGA-based pattern generator. Use Value: Dual OE control allows per-channel enable/disable during test sequence execution, reducing crosstalk and improving measurement repeatability.

Microcontroller Bus Interface

Industrial I/O Expansion

Use Scenario: Interfacing an 8-bit microcontroller data bus to external peripherals with mismatched voltage or drive requirements.

IC Role / Device Role / Timing Role: Bidirectional buffer providing level translation, fanout amplification, and bus isolation during wait states.

Use Value: Eliminates need for discrete level shifters and reduces PCB area by consolidating eight channels in one SOIC-20 package.

Use Scenario: Adding parallel digital I/O capability to PLC modules or sensor concentrators operating in noisy factory environments.

IC Role / Device Role / Timing Role: Inverting line driver isolating field-side logic from controller-side logic while maintaining signal integrity.

Use Value: ±8 mA drive sustains signal margins over longer traces; 3-state control enables dynamic bus sharing among multiple expansion cards.

Memory Address Latching

Test Equipment Signal Conditioning

Use Scenario: Driving address lines to SRAM or EPROM devices where inverted addressing is required or tolerated.

IC Role / Device Role / Timing Role: Inverting buffer with precise propagation delay used in address decode path to meet setup/hold timing windows.

Use Value: 7.5 ns delay is predictable and stable across temperature, enabling deterministic timing budget allocation in memory subsystems.

Use Scenario: Conditioning digital stimulus/response signals in automated test equipment (ATE) channel cards.

IC Role / Device Role / Timing Role: Signal conditioner providing gain, inversion, and bus isolation between DUT interface and FPGA-based pattern generator.

Use Value: Dual OE control allows per-channel enable/disable during test sequence execution, reducing crosstalk and improving measurement repeatability.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74HCT240N	Same logic function and pinout; slightly higher max propagation delay (8.5 ns vs. 7.5 ns) and lower output drive (±4 mA).	Less suitable for high-speed or high-fanout bus loading; acceptable for static I/O expansion.	Prefer MC74VHCT240AMELG when >±6 mA drive or sub-8 ns timing is required.
74VHC240M	CMOS-input variant (not TTL-compatible); requires ≥3.5 V input high threshold; identical output specs and timing.	Cannot directly replace TTL-driven systems without upstream level shifting.	Select MC74VHCT240AMELG for mixed-logic systems with legacy TTL sources.

Compared with SN74HCT240N and 74VHC240M, the MC74VHCT240AMELG uniquely balances TTL input compatibility, ±8 mA drive, and 7.5 ns speed-making it optimal for industrial bus interfaces where signal integrity, legacy interoperability, and timing margin are jointly critical.

Availability

MC74VHCT240AMELG is available at Aetrix Electronics and suitable for industrial automation, test equipment, and microcontroller peripheral interfacing requiring stable component supply and long-term lifecycle assurance.

Supply support for MC74VHCT240AMELG 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 leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MC74VHCT240AMELG belongs to the VHCT logic family, engineered specifically for seamless integration between TTL-based legacy systems and modern CMOS-based controllers-emphasizing reliability, noise immunity, and industrial temperature resilience.

FAQ

What is the input voltage threshold specification for MC74VHCT240AMELG?

The MC74VHCT240AMELG has TTL-compatible input thresholds: V_IL ≤ 0.8 V (maximum) guarantees logic-low recognition, and V_IH ≥ 2.0 V (minimum) ensures reliable logic-high detection. These values are tested and guaranteed across the full –40 °C to +85 °C operating range, making MC74VHCT240AMELG suitable for mixed-signal systems with legacy TTL outputs.

Does MC74VHCT240AMELG support hot-swap or live insertion?

Yes, MC74VHCT240AMELG supports hot-swap operation when its output-enable (OE) inputs are held inactive (high), placing all outputs in high-impedance state. With OE high, input leakage remains below ±1 µA and output off-state leakage stays under ±10 µA, preventing bus contention during insertion-confirmed per onsemi's application guidance for industrial backplane interfaces using MC74VHCT240AMELG.

What is the maximum capacitive load MC74VHCT240AMELG can drive reliably?

MC74VHCT240AMELG is characterized to drive up to 15 pF loads while maintaining specified propagation delay (7.5 ns) and output voltage swing (V_OH ≥ 4.4 V, V_OL ≤ 0.1 V at V_CC = 5 V). Driving larger capacitances increases rise/fall times and may violate timing budgets; for >15 pF, consider buffering or layout optimization alongside MC74VHCT240AMELG.

Is MC74VHCT240AMELG pin-compatible with older 74LS240 devices?

No, MC74VHCT240AMELG is not pin-compatible with 74LS240. While both are octal inverting 3-state buffers, 74LS240 uses a 20-pin dual-in-line package (DIP) with different pin assignments-especially for OE and power pins. MC74VHCT240AMELG follows SOIC-20 pinout per onsemi's package drawing, and direct replacement requires PCB redesign. Always verify pin mapping before substitution involving MC74VHCT240AMELG.

What is the quiescent supply current of MC74VHCT240AMELG at 5 V?

The quiescent supply current (I_CC) for MC74VHCT240AMELG is typically 4 µA and guaranteed ≤ 40 µA over the full operating temperature range (–40 °C to +85 °C) with all inputs static and outputs disabled. This ultra-low standby current makes MC74VHCT240AMELG suitable for power-sensitive industrial control modules where MC74VHCT240AMELG remains powered but inactive for extended periods.

MC74VHCT240AMELG Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74VHCT

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:: 8mA, 8mA

Voltage - Supply:: 4.5V ~ 5.5V

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOEIAJ-20

MC74VHCT240AMELG FAQ

1.How can I place an order for MC74VHCT240AMELG through Aetrix?

Please submit a Request for Quotation (RFQ) for MC74VHCT240AMELG 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 MC74VHCT240AMELG reliable?

The price and inventory of MC74VHCT240AMELG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC74VHCT240AMELG is usually 5 days.

3.What payment methods are accepted for MC74VHCT240AMELG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC74VHCT240AMELG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MC74VHCT240AMELG?

MC74VHCT240AMELG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MC74VHCT240AMELG 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 MC74VHCT240AMELG?

For technical support, including MC74VHCT240AMELG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC74VHCT240AMELG requirements.

6.How does Aetrix verify that MC74VHCT240AMELG is sourced from the original manufacturer or authorized distributors?

All MC74VHCT240AMELG 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 MC74VHCT240AMELG meets industry standards.

7.What is the process for return or replacement of MC74VHCT240AMELG?

All MC74VHCT240AMELG units undergo pre-shipment inspection (PSI). If there is an issue with MC74VHCT240AMELG, 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 MC74VHCT240AMELG part is unused and in its original packaging.

Return procedure for MC74VHCT240AMELG:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…