NXP Semiconductors 74HC240PW,112

Overview

74HC240PW,112 from Nexperia is an octal inverting 3-state buffer/line driver in TSSOP20 package, operating from 2.0 V to 6.0 V supply, with propagation delay as low as 9 ns at VCC = 5.0 V and CL = 15 pF, used for bidirectional bus isolation and address/data buffering in industrial control logic systems.

For engineers reviewing the 74HC240PW,112 datasheet, 74HC240PW,112 pinout, 74HC240PW,112 application, or 74HC240PW,112 equivalent, key selection criteria include 3-state enable timing (ten ≤ 30 ns), input voltage compatibility (CMOS-level), thermal performance in TSSOP20 (derates 10.0 mW/K above 100 °C), and dual independent output enables for segmented bus control.

Technical Context

The device implements two independent 4-bit inverting buffer sections, each controlled by a dedicated active-low output enable (1OE, 2OE), allowing selective tri-state control of eight outputs grouped as Y0–Y3 per section. Inputs feature clamp diodes enabling safe interfacing to voltages exceeding VCC when current-limiting resistors are used.

It operates across -40 °C to +125 °C, supports static drive capability of ±6.0 mA at VCC = 4.5 V, and exhibits CMOS-level input thresholds (VIH ≥ 3.15 V, VIL ≤ 1.35 V at VCC = 4.5 V) with input leakage < ±1.0 μA over full temperature range.

Key Specifications

Pinout & Package

TSSOP20 plastic thin shrink small outline package (SOT360-1), 20-lead, body width 4.4 mm, 0.65 mm pitch, exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal inverting 3-state buffer applications.

Compared with 74HCT240PW,112, the 74HC240PW,112 offers lower static power and wider supply flexibility but requires CMOS-level inputs; versus SN74LVC240APWR, it trades speed and voltage headroom for robustness against overvoltage and broader temperature compliance.

Availability

74HC240PW,112 is available at Aetrix Electronics and suitable for industrial PLC backplanes, embedded microcontroller bus isolation, test equipment signal routing, and legacy communication interfaces requiring stable component supply across extended temperature ranges.

Supply support for 74HC240PW,112 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

Nexperia is a global semiconductor expert delivering high-performance, reliable logic, analog, and MOSFET solutions for industrial, automotive, and consumer applications.

The 74HC240 belongs to Nexperia's HC-series logic family, designed specifically for high-noise-immunity, wide-supply industrial control systems requiring robust 3-state bus management without external level translation.

FAQ

Can 74HC240PW,112 be used with 3.3 V microcontrollers?

Yes - the 74HC240PW,112 operates down to 2.0 V and accepts CMOS-level inputs, making it fully compatible with 3.3 V microcontrollers. At VCC = 3.3 V, VIH is guaranteed ≥2.1 V and VIL ≤1.35 V, ensuring reliable logic recognition. Output VOH exceeds 2.9 V at IO = -4 mA, sufficient to drive standard 3.3 V CMOS inputs.

What is the maximum capacitive load the outputs can drive?

The outputs are characterized up to 50 pF load capacitance in the datasheet, with transition times specified at 15 pF and 50 pF. Driving >50 pF may increase tt beyond 18 ns and cause marginal timing in high-speed buses. For loads >50 pF, add series termination or reduce trace length; the device's ±6.0 mA drive strength supports typical PCB traces and short stubs without external buffers.

Is the exposed pad on the TSSOP20 package electrically connected?

No - the exposed pad in the SOT360-1 (TSSOP20) package is not electrically connected to any internal node. Per Nexperia's documentation, it has no electrical or mechanical requirement to be soldered. If soldered, it must remain floating or be connected to GND; thermal performance improvement is marginal (<2 °C/W) and not guaranteed without validated thermal modeling.

How does the 74HC240 differ from the 74LS240 in practical design?

The 74HC240 draws significantly less quiescent current (≤80 μA vs. ~20 mA for 74LS240), operates over wider voltage (2.0–6.0 V vs. 4.75–5.25 V), and provides symmetrical drive (±6 mA vs. asymmetric LS sink/source). It also features input clamp diodes and higher ESD tolerance. Unlike 74LS240, it cannot directly interface with TTL outputs without level shifting at 3.3 V supply due to higher VIH threshold.