onsemi 74LVX240SJX

Overview

74LVX240SJX from Fairchild Semiconductor is an octal inverting buffer/line driver with dual 3-STATE output enables (OE1, OE2), designed for memory address and clock distribution in mixed-voltage systems. It operates from 2.0V to 3.6V VCC, tolerates 5.5V inputs, delivers ±4mA drive at 3.3V, and features propagation delays as low as 4.3ns (CL = 15pF). It is used in 3.3V bus interface applications between 5V legacy peripherals and low-voltage logic.

For engineers reviewing the 74LVX240SJX datasheet, pinout, applications, or equivalent options, key selection criteria include input voltage translation capability (0–5.5V into 2.0–3.6V system), simultaneous switching noise immunity, guaranteed tPZL/tPLZ timing under 13ns, and EIAJ TYPE II SOP-20 package compatibility.

Technical Context

The 74LVX240SJX implements eight independent inverting buffers, each with output enable control partitioned across two groups (OE1 controls O0–O3; OE2 controls O4–O7). Its input structure supports 5V-tolerant CMOS inputs, enabling direct interfacing with higher-voltage logic without level shifters.

It uses advanced low-voltage CMOS process technology to achieve sub-5ns typical propagation delay at 3.3V while maintaining <±0.25µA off-state leakage and <40µA quiescent ICC. Dynamic noise parameters (VOLP/VOLV) are specified at CL = 50pF, confirming robustness in high-speed bus environments.

Key Specifications

Pinout & Package

74LVX240SJX is packaged in a 20-lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm wide (Package Number M20D), with gull-wing leads and standard 0.5mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74LVX240SJX, the 74LVC240PW offers speed and lower voltage operation but lacks input voltage translation, while SN74LV240APWR adds drive strength and supply range but removes 5V tolerance - making 74LVX240SJX uniquely suited for legacy 5V-to-3.3V bridging where polarity inversion is acceptable.

Availability

74LVX240SJX is available at Aetrix Electronics and suitable for memory address buffering, 3.3V/5V bus interfacing, and clock distribution applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across temperature.

Supply support for 74LVX240SJX 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

Fairchild Semiconductor was a U.S.-based designer and manufacturer of analog and mixed-signal semiconductors, acquired by ON Semiconductor in 2016; its legacy logic portfolio remains widely deployed and supported.

The 74LVX240SJX belongs to the LVX low-voltage logic family, engineered specifically for interoperability between 3.3V and 5V systems while minimizing power and noise in space-constrained board layouts.

FAQ

What is the maximum input voltage the 74LVX240SJX can tolerate?

The 74LVX240SJX supports DC input voltages from −0.5V to 5.5V regardless of VCC level, enabling direct connection to 5V logic families without damage or level-shifting circuitry. This 5V-tolerance is guaranteed across the full operating temperature range (−40°C to +85°C) and is a defining feature of the LVX series. The 74LVX240SJX achieves this through specially designed input protection structures that clamp excess voltage while maintaining correct logic interpretation at the core gates.

Does the 74LVX240SJX have inverting or non-inverting outputs?

The 74LVX240SJX has inverting outputs: each output (O0–O7) is the logical complement of its corresponding input (I0–I7). This behavior is confirmed in the truth table and functional description in the official Fairchild datasheet DS011609. When using the 74LVX240SJX in a design, signal polarity must be accounted for - for example, an active-HIGH input produces an active-LOW output. The 74LVX240SJX does not offer a non-inverting variant in the same package and pinout.

What is the recommended operating VCC range for the 74LVX240SJX?

The 74LVX240SJX is specified to operate reliably from 2.0V to 3.6V VCC, with all DC and AC electrical characteristics guaranteed across this range at temperatures from −40°C to +85°C. Operation below 2.0V may result in undefined logic states or increased propagation delay; above 3.6V violates absolute maximum ratings and risks permanent damage. The 74LVX240SJX achieves optimal noise margin and speed at 3.3V, where VIH is 2.4V and tPLH is 4.3ns (typical).

How are the 3-STATE outputs controlled on the 74LVX240SJX?

The 74LVX240SJX uses two independent active-low 3-STATE enable inputs: OE1 (pin 1) controls outputs O0–O3, and OE2 (pin 19) controls outputs O4–O7. When an OE pin is LOW, its associated outputs drive their inverted input values; when HIGH, those outputs enter high-impedance state. This partitioning allows partial bus control - for example, disabling only the upper or lower nibble of a byte-wide bus. The 74LVX240SJX truth table explicitly defines this behavior with "Z" denoting high-impedance output.

Is the 74LVX240SJX RoHS compliant and lead-free?

Yes, the 74LVX240SJX is RoHS compliant and lead-free. As indicated in Fairchild's product change notices and packaging documentation, the "X" suffix in 74LVX240SJX denotes tape-and-reel packaging and confirms compliance with EU RoHS Directive 2011/65/EU. The device uses matte tin lead finish and Pb-free mold compound. This applies to units manufactured post-2006; earlier lots may carry different markings but remain compatible. The 74LVX240SJX meets JEDEC J-STD-020 moisture sensitivity level 1 requirements.