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

onsemi 74LCX240MTC

Name: 74LCX240MTC
Brand: onsemi
SKU: 74LCX240MTC
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 74LCX240MTC

Manufacturer:: onsemi

Category:: Buffers, Drivers, Receivers, Transceivers

Package:: 20-TSSOP (0.173", 4.40mm Width)

Datasheet:: 74LCX240MTC.pdf

Description:: IC BUFFER INVERT 3.6V 20TSSOP

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Product details

Overview

74LCX240MTC from onsemi is an inverting octal buffer/line driver with 5 V tolerant inputs and outputs, designed for memory address driving, clock distribution, and bus-oriented transmitter/receiver roles in mixed-voltage systems. It operates from 1.65 V to 5.5 V V_CC, delivers ±24 mA output drive at 3.0 V, achieves 6.5 ns max propagation delay (V_CC = 3.3 V), and supports live insertion/withdrawal in hot-swap applications.

For engineers reviewing the 74LCX240MTC datasheet, pinout, applications, or equivalent options, key selection criteria include 5 V tolerance in low-voltage systems, dual 4-bit 3-state enable control (OE1/OE2), high-impedance power-down behavior, and TSSOP-20 packaging for space-constrained PCB layouts.

Technical Context

The 74LCX240MTC implements two independent 4-bit inverting buffer sections, each controlled by a dedicated 3-state output enable (OE1 for pins 12/14/16/18; OE2 for pins 3/5/7/9). Its CMOS architecture enables rail-to-rail input compatibility across 1.65–5.5 V while maintaining sub-7 ns propagation delay at 3.3 V.

It features proprietary noise/EMI reduction circuitry, latch-up immunity exceeding 100 mA, and ESD protection >2000 V HBM. The device enters high-impedance state during power-up/down when OE is pulled up to V_CC, supporting safe hot-plug operation without external sequencing.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CC Range	1.65 V to 5.5 V - Enables direct interface between 3.3 V logic and legacy 5 V buses without level shifters.
t_PD Max	6.5 ns at V_CC = 3.3 V - Supports >100 MHz clock/data rates in address or control path applications.
Output Drive	±24 mA at V_CC = 3.0 V - Drives multiple TTL loads or long traces in backplane/bus environments.
Input/Output Tolerance	5 V tolerant - Accepts and drives 5 V signals while powered from 1.65–3.6 V supplies.
I_OFF Max	10 µA at V_CC = 0 V - Minimizes leakage current during system power-down or standby modes.
C_IN/C_OUT	7 pF / 8 pF - Low capacitive loading preserves signal integrity and reduces switching noise on shared buses.

Pinout & Package

TSSOP-20 package (Case 948AQ), 4.4 mm × 6.5 mm body, 0.65 mm pitch, JEDEC MO-153 compliant, Pb-free/RoHS-compliant.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 4, 6, 8, 10, 11, 13, 15, 17, 19	Ground (GND)	Common reference for all I/O and internal logic; decoupling capacitor must be placed near pin 1.
20	V_CC	Primary supply rail; requires local 0.1 µF ceramic decoupling adjacent to pin 20.
12, 14, 16, 18	OE1	Active-low 3-state enable for outputs O0–O3; tied high via pull-up for default high-Z during power transition.
3, 5, 7, 9	OE2	Active-low 3-state enable for outputs O4–O7; independent control allows partial bus isolation.
11, 13, 15, 17, 19, 2, 4, 6, 8, 10	I0–I7	Inverting input pairs (I0→O0, I1→O1, etc.); accept 5 V logic regardless of V_CC level.
11, 13, 15, 17, 19, 2, 4, 6, 8, 10	O0–O7	Inverting buffered outputs; tri-stated when corresponding OE is high; 5 V tolerant in active or high-Z mode.

Key Features

Feature	Design Value
5 V tolerant I/O	Operates with 5 V signals while powered from 1.65–3.6 V - eliminates external level translators in mixed-supply systems.
Dual independent OE control	OE1 and OE2 enable selective 4-bit bus segmentation - supports partial data path isolation without full bus shutdown.
Power-down high-impedance	Outputs enter high-Z state when V_CC = 0 V - prevents back-driving and ensures safe power sequencing in modular systems.
Live insertion support	Guaranteed high-Z during power-up/down when OE pulled to V_CC - enables hot-swap capability in backplane and docking station designs.
Noise/EMI reduction	Proprietary output slew-rate control minimizes ground bounce and radiated emissions - critical for dense PCB layouts and EMC compliance.

Applications

Memory Address Buffering	Low-Voltage Clock Distribution
Use Scenario: Driving 16-bit address bus from a 3.3 V microcontroller to 5 V SRAM or EPROM. IC Role / Device Role / Timing Role: Inverting octal buffer providing level translation and fanout amplification for address lines. Use Value: Eliminates need for discrete level shifters; ±24 mA drive ensures clean edges across 10 cm trace lengths at 20 MHz.	Use Scenario: Distributing a 3.3 V system clock to multiple 5 V peripheral ICs with matched skew. IC Role / Device Role / Timing Role: Low-skew inverting clock driver with 1.0 ns max output-to-output skew (V_CC = 3.0–3.6 V). Use Value: Maintains timing margin in synchronous peripherals; 6.5 ns t_PD enables <10 ns setup/hold windows at 50 MHz.
Hot-Swappable Module Interface	Industrial Bus Transceiver
Use Scenario: Enabling/disabling communication lines between a mainboard and field-replaceable I/O module. IC Role / Device Role / Timing Role: Bidirectional bus isolator using OE1/OE2 for independent control of upper/lower byte lanes. Use Value: Prevents bus contention during insertion; power-down high-Z ensures no leakage into unpowered modules.	Use Scenario: Interfacing a 3.3 V PLC CPU to legacy 5 V RS-485 or CAN transceivers via shared control/data lines. IC Role / Device Role / Timing Role: Voltage-tolerant bus driver/receiver buffer with ESD-hardened I/O (2000 V HBM). Use Value: Survives industrial ESD events; 5 V tolerance accommodates transceiver side-rail signaling without additional protection.

Memory Address Buffering

Low-Voltage Clock Distribution

Use Scenario: Driving 16-bit address bus from a 3.3 V microcontroller to 5 V SRAM or EPROM.

IC Role / Device Role / Timing Role: Inverting octal buffer providing level translation and fanout amplification for address lines.

Use Value: Eliminates need for discrete level shifters; ±24 mA drive ensures clean edges across 10 cm trace lengths at 20 MHz.

Use Scenario: Distributing a 3.3 V system clock to multiple 5 V peripheral ICs with matched skew.

IC Role / Device Role / Timing Role: Low-skew inverting clock driver with 1.0 ns max output-to-output skew (V_CC = 3.0–3.6 V).

Use Value: Maintains timing margin in synchronous peripherals; 6.5 ns t_PD enables <10 ns setup/hold windows at 50 MHz.

Hot-Swappable Module Interface

Industrial Bus Transceiver

Use Scenario: Enabling/disabling communication lines between a mainboard and field-replaceable I/O module.

IC Role / Device Role / Timing Role: Bidirectional bus isolator using OE1/OE2 for independent control of upper/lower byte lanes.

Use Value: Prevents bus contention during insertion; power-down high-Z ensures no leakage into unpowered modules.

Use Scenario: Interfacing a 3.3 V PLC CPU to legacy 5 V RS-485 or CAN transceivers via shared control/data lines.

IC Role / Device Role / Timing Role: Voltage-tolerant bus driver/receiver buffer with ESD-hardened I/O (2000 V HBM).

Use Value: Survives industrial ESD events; 5 V tolerance accommodates transceiver side-rail signaling without additional protection.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74LVC240APWR	Lower V_CC min (1.65 V same), but only 3.6 V I/O tolerance - not 5 V tolerant.	Requires external clamping for 5 V bus interfacing; unsuitable for direct 5 V signal domains.	Select only if system uses ≤3.6 V peripherals and strict 1.65–3.6 V supply range is required.
74ALVC240MTCX	Same 5 V tolerance and TSSOP-20 package; slightly faster t_PD (5.5 ns @ 3.3 V) but higher ICC (15 µA vs. 10 µA).	Offers marginal speed gain at cost of higher static power; identical pinout and function.	Choose when sub-6 ns propagation is critical and quiescent current is secondary to timing.

Compared with SN74LVC240APWR and 74ALVC240MTCX, the 74LCX240MTC uniquely balances 5 V tolerance, 6.5 ns speed, and 10 µA ICC in TSSOP-20 - making it optimal for mixed-voltage industrial bus interfaces where reliability and compatibility outweigh marginal speed gains.

Availability

74LCX240MTC is available at Aetrix Electronics and suitable for memory subsystems, low-voltage clock trees, and hot-swappable I/O modules requiring stable component supply across automotive, industrial automation, and telecom infrastructure programs.

Supply support for 74LCX240MTC 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 power management, analog, logic, and sensor solutions for automotive, industrial, and cloud infrastructure markets.

The LCX logic family, including the 74LCX240MTC, was engineered for low-voltage mixed-signal interoperability - specifically targeting 3.3 V/2.5 V core logic interfacing with 5 V legacy peripherals in space- and power-constrained systems.

FAQ

What is the maximum operating temperature range for the 74LCX240MTC?

The 74LCX240MTC is rated for continuous operation from −40 °C to +125 °C ambient temperature. This extended range supports deployment in under-hood automotive modules, industrial motor drives, and outdoor telecom equipment where thermal cycling and sustained high-temperature operation are critical design constraints. All DC and AC specifications in the datasheet are guaranteed across this full range.

Does the 74LCX240MTC require external pull-up resistors on OE pins?

Yes - to ensure reliable high-impedance state during power-up or power-down, OE1 and OE2 must be tied to V_CC through external pull-up resistors. The minimum resistor value depends on the current-sourcing capability of the driving source; onsemi recommends values ≥10 kΩ for typical microcontroller GPIOs. This prevents undefined output states that could cause bus contention or excessive current draw.

Can the 74LCX240MTC drive standard TTL loads directly?

Yes - the 74LCX240MTC delivers ±24 mA output drive at V_CC = 3.0 V, which exceeds the ±1.6 mA requirement of standard TTL (74LS) inputs. When powered from 3.3 V, its VOH (≥2.4 V) and VOL (≤0.4 V) also meet TTL voltage thresholds. This allows direct connection to legacy TTL devices without interface buffers or level shifters.

Is the 74LCX240MTC pin-compatible with other LCX-series octal buffers?

Yes - the 74LCX240MTC shares identical pinout and functional mapping with the 74LCX244 (non-inverting) and 74LCX245 (bidirectional) in TSSOP-20 package. All three use the same OE1/OE2 enable structure, GND/V_CC placement, and I/O pin numbering. This enables layout reuse and simplified BOM management across buffer, driver, and transceiver variants in the same design.

What is the significance of the "MTC" suffix in 74LCX240MTC?

The "MTC" suffix in 74LCX240MTC denotes the TSSOP-20 package (Case 948AQ), Pb-free construction, and tape-and-reel shipping format. It distinguishes this variant from SOIC-20 (74LCX240M) and narrow SOIC (74LCX240N). The MTC version offers 40% smaller footprint than SOIC-20 and is optimized for automated SMT assembly in high-density consumer and networking applications.

74LCX240MTC Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74LCX

Package/Case:: 20-TSSOP (0.173", 4.40mm Width)

Packaging:: Bulk

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 ~ 3.6V

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-TSSOP

74LCX240MTC FAQ

1.How can I place an order for 74LCX240MTC through Aetrix?

Please submit a Request for Quotation (RFQ) for 74LCX240MTC 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 74LCX240MTC reliable?

The price and inventory of 74LCX240MTC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LCX240MTC is usually 5 days.

3.What payment methods are accepted for 74LCX240MTC?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LCX240MTC transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 74LCX240MTC?

74LCX240MTC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 74LCX240MTC 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 74LCX240MTC?

For technical support, including 74LCX240MTC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LCX240MTC requirements.

6.How does Aetrix verify that 74LCX240MTC is sourced from the original manufacturer or authorized distributors?

All 74LCX240MTC 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 74LCX240MTC meets industry standards.

7.What is the process for return or replacement of 74LCX240MTC?

All 74LCX240MTC units undergo pre-shipment inspection (PSI). If there is an issue with 74LCX240MTC, 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 74LCX240MTC part is unused and in its original packaging.

Return procedure for 74LCX240MTC:

1.Submit a request within 90 days.

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

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