onsemi 74LCX16240MTDX

Overview

74LCX16240MTDX from ON Semiconductor is a low-voltage 16-bit inverting buffer/line driver with 5V-tolerant inputs and outputs, designed for memory/address bus driving and clock distribution in 2.5V/3.3V systems interfacing to 5V logic. It features nibble-level 3-STATE control, 4.5 ns max propagation delay at 3.3V, ±24 mA output drive, and operates from 2.3V to 3.6V V_CC.

For engineers reviewing the 74LCX16240MTDX datasheet, pinout, applications, or equivalent options, key selection criteria include 5V tolerance across I/O, dual-nibble 3-STATE enable architecture, low ICC (20 µA max), high noise immunity, and TSSOP-48 packaging for space-constrained board layouts.

Technical Context

The 74LCX16240MTDX implements sixteen independent inverting buffers grouped into four 4-bit nibbles, each with dedicated active-low Output Enable (OE) inputs (OE1–OE4). Its CMOS design enables rail-to-rail 5V-tolerant I/O while operating from a 2.3–3.6V supply - supporting mixed-voltage system interconnect without level shifters.

Each output delivers up to 24 mA sink/source capability at 3.0V V_CC, with guaranteed high-impedance states during power-up/down when OE is pulled high via external resistor. Propagation delay skew is limited to 1.0 ns between any two outputs switching in the same direction, ensuring timing integrity in parallel bus applications.

Key Specifications

Pinout & Package

74LCX16240MTDX is housed in a 48-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, 6.1 mm wide, with 0.5 mm lead pitch. This package supports fine-pitch surface-mount assembly and provides thermal and mechanical reliability for automated PCB production.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit inverting buffer applications.

Compared with 74ALVC16240PW,118 and SN74LVC16240ADGGR, the 74LCX16240MTDX uniquely guarantees 5V-tolerant I/O without external components across its full operating range - making it the only drop-in solution for mixed-voltage backplanes requiring robustness against voltage transients and legacy bus integration.

Availability

74LCX16240MTDX is available at Aetrix Electronics and suitable for memory subsystems, industrial backplanes, programmable logic interfaces, and legacy bus bridging applications requiring stable component supply, long-term lifecycle support, and guaranteed 5V-tolerant interoperability.

Supply support for 74LCX16240MTDX 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, logic, and custom devices for automotive, industrial, cloud computing, and IoT applications.

The 74LCX16240MTDX belongs to ON Semiconductor's legacy LCX logic family - engineered specifically for low-voltage, high-speed, mixed-signal interfacing where 5V tolerance, low power, and precise timing control are essential.

FAQ

What is the maximum recommended V_CC voltage for reliable operation of the 74LCX16240MTDX?

The 74LCX16240MTDX is rated for V_CC from 2.3 V to 3.6 V under recommended operating conditions. While absolute maximum rating permits up to 7.0 V, operation above 3.6 V violates specification limits and risks parametric failure, increased leakage, or accelerated wear-out. Always maintain V_CC ≤ 3.6 V for guaranteed timing, drive strength, and 5V-tolerant I/O behavior in the 74LCX16240MTDX.

Does the 74LCX16240MTDX require external pull-up resistors on OE pins for proper power-up behavior?

Yes - to ensure outputs remain in high-impedance state during power-up or power-down, each OE pin (OE1–OE4) must be tied to V_CC through an external pull-up resistor. The minimum resistance value depends on the driving source's current-sourcing capability, as specified in Fairchild Application Note AN-118. This requirement applies directly to the 74LCX16240MTDX and prevents bus contention in systems with asynchronous power sequencing.

Can the 74LCX16240MTDX safely drive a 50 pF load at 3.3V while maintaining 4.5 ns propagation delay?

Yes - the 74LCX16240MTDX specifies t_PHL/t_PLH ≤ 4.5 ns at V_CC = 3.3V ±0.3V with C_L = 50 pF, as confirmed in the AC Electrical Characteristics table. This performance is measured under standard test conditions using the defined AC loading circuit (Figure 1), and remains valid for the 74LCX16240MTDX in production-grade TSSOP-48 packaging.

Is the 74LCX16240MTDX pin-compatible with the 74LCX16244MTDX?

No - the 74LCX16240MTDX is an inverting buffer (I→¬O), whereas the 74LCX16244MTDX is a non-inverting buffer (I→O). Though both share identical pinouts, package (TSSOP-48), and electrical specifications, their logic functions differ fundamentally. Substituting one for the other without adjusting upstream/downstream logic will invert critical control or data signals - invalidating functional correctness in the 74LCX16240MTDX application.

What is the latch-up immunity rating for the 74LCX16240MTDX, and how is it verified?

The 74LCX16240MTDX exhibits latch-up immunity exceeding 500 mA, as tested per JEDEC Standard JESD78. This rating is confirmed in the original Fairchild DS011999 datasheet and maintained under ON Semiconductor's product continuity program. The value reflects worst-case stress applied to all I/O pins simultaneously and ensures robust operation in electrically noisy industrial environments where the 74LCX16240MTDX is commonly deployed.