NXP Semiconductors 74AHC240PW,118

Overview

74AHC240PW,118 from NXP Semiconductors is an 8-bit inverting buffer/line driver with dual 3-state output enables (1OE and 2OE), operating from 2.0 V to 5.5 V supply, featuring overvoltage-tolerant inputs up to 7.0 V and Schmitt-trigger input action. It supports mixed-voltage translation between 3.3 V and 5 V domains and is rated for operation from −40 °C to +125 °C in a TSSOP20 package.

For engineers reviewing the 74AHC240PW,118 datasheet, 74AHC240PW,118 pinout, 74AHC240PW,118 application, or 74AHC240PW,118 equivalent, key selection considerations include its CMOS-level input compatibility, balanced propagation delays (as low as 2.8 ns at 5 V/15 pF), high-impedance output control per 4-bit group, and ESD robustness (HBM >2000 V).

Technical Context

The 74AHC240PW,118 implements two independent 4-bit inverting buffer sections, each controlled by a dedicated active-low output enable (1OE for outputs Y0–Y3; 2OE for Y0–Y3 of second group). Its overvoltage-tolerant inputs allow safe interfacing with higher-voltage logic while powered from lower VCC - enabling level-shifting without external components.

Each output drives up to ±8 mA at 4.5 V and exhibits tightly matched tPLH/tPHL propagation delays. The device uses standard CMOS input thresholds (VIH = 3.85 V min at VCC = 5.5 V) and supports dynamic power calculation via CPD = 9 pF, making it suitable for low-power, noise-immune bus interface applications in industrial and embedded systems.

Key Specifications

Pinout & Package

TSSOP20 package (SOT360-1): plastic thin shrink small outline, 20 leads, 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 buffer applications.

Compared with 74AHC240D,118, the 74AHC240PW,118 offers 35 % smaller PCB area and improved thermal performance; compared with SN74AHC240PWR, it delivers marginally faster propagation delay and shares full functional equivalence for drop-in replacement in most designs.

Availability

74AHC240PW,118 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, embedded microcontroller bus interface, test equipment signal conditioning, and automotive diagnostic interface modules requiring stable component supply across extended temperature ranges.

Supply support for 74AHC240PW,118 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

NXP Semiconductors is a global semiconductor company specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The 74AHC240PW,118 belongs to NXP's AHC logic family, designed for high-speed, low-power, mixed-voltage digital interfacing in space-constrained industrial and embedded systems.

FAQ

What is the maximum input voltage the 74AHC240PW,118 can tolerate?

The 74AHC240PW,118 accepts input voltages from −0.5 V to +7.0 V, independent of VCC. This overvoltage tolerance allows direct connection to 5 V logic while operating from a 3.3 V supply - eliminating external level-shifting components. The specification is validated per absolute maximum ratings and applies across the full −40 °C to +125 °C temperature range.

Does the 74AHC240PW,118 support TTL-level inputs?

No, the 74AHC240PW,118 is optimized for CMOS input thresholds (VIH ≥ 3.85 V at VCC = 5.5 V) and does not guarantee reliable operation with standard TTL input levels (VIH = 2.0 V). For TTL-compatible operation, use the pin-compatible 74AHCT240PW,118 variant instead - which maintains identical packaging and pinout but features adjusted input thresholds.

How does the dual output enable (1OE and 2OE) function in the 74AHC240PW,118?

The 74AHC240PW,118 provides two independent active-low output enables: 1OE controls outputs 1Y0–1Y3, and 2OE controls outputs 2Y0–2Y3. When either OE is HIGH, its associated four outputs enter high-impedance state; when LOW, they actively drive inverted inputs. This enables selective bus segmentation - for example, isolating memory address vs. data lines - without affecting the other group.

What is the typical propagation delay of the 74AHC240PW,118 at 5 V supply?

At VCC = 5 V and CL = 15 pF, the 74AHC240PW,118 exhibits a typical propagation delay (tpd) of 2.8 ns, with a maximum of 4.8 ns over temperature (−40 °C to +125 °C). This value applies to both tPLH and tPHL transitions and is measured from input (nAn) to corresponding output (nYn), ensuring predictable timing in high-speed digital interfaces.

Is the exposed pad on the TSSOP20 package of the 74AHC240PW,118 electrically connected?

No, the exposed pad on the 74AHC240PW,118's TSSOP20 (SOT360-1) package is not electrically connected. As stated in the datasheet, it is attached to the substrate using conductive die attach material but has no electrical or mechanical requirement to be soldered. If soldered, the land must remain floating or be connected to GND - it must not be tied to VCC or any signal net.