NXP Semiconductors N74F240N,602

Overview

N74F240N,602 from Philips Semiconductors is an octal inverting 3-state buffer IC designed for bus interface and memory address register driving in TTL-compatible digital systems. It features dual active-low output enables (OEa/OEb), 4.3 ns typical propagation delay, ±15 mA high-level / 64 mA low-level output drive, and operates at 5 V ±10% over 0 °C to +70 °C.

For engineers reviewing the N74F240N,602 datasheet, N74F240N,602 pinout, N74F240N,602 application, or N74F240N,602 equivalent, key selection criteria include 3-state bus contention control, dual independent enable logic, TTL-level input thresholds (VIL = 0.8 V, VIH = 2.0 V), and DIP20 package compatibility with legacy through-hole layouts.

Technical Context

The N74F240N,602 implements two independent 4-bit inverting buffer groups (Ia0–Ia3 → Ya0–Ya3 and Ib0–Ib3 → Yb0–Yb3), each controlled by its own active-low output enable (OEa, OEb). All outputs enter high-impedance state when their respective enable is HIGH.

It adheres to FAST TTL logic family specifications: 20 µA input leakage, 15 mA IOH, 64 mA IOL, 37 mA typical total supply current, and AC timing validated at CL = 50 pF / RL = 500 Ω with 3.0–7.5 ns propagation and 3.0–10.0 ns enable/disable delays.

Key Specifications

Pinout & Package

Package: Plastic dual in-line package (DIP20), 300 mil width, 2.54 mm pitch, SOT146-1 footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74F240N and 74ACT240PC, the N74F240N,602 provides guaranteed TTL-level compatibility, proven reliability in long-lifecycle industrial systems, and direct DIP20 socket replacement - making it optimal for maintenance, repair, and legacy design continuity where electrical and mechanical interchangeability is mandatory.

Availability

N74F240N,602 is available at Aetrix Electronics and suitable for memory address buffering, bus isolation interfaces, legacy system bus expansion, and industrial I/O module interfaces requiring stable component supply and long-term obsolescence management.

Supply support for N74F240N,602 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

Philips Semiconductors (now NXP Semiconductors) is a Dutch semiconductor pioneer known for foundational TTL, CMOS, and analog IC development, with emphasis on industrial reliability and broad logic family standardization.

The 74F FAST TTL series - including the N74F240N,602 - was engineered for high-speed, high-drive digital interfacing in computing, instrumentation, and telecom infrastructure where speed, noise immunity, and bus-loading capability were critical.

FAQ

What is the logic function of the N74F240N,602?

The N74F240N,602 is an octal inverting 3-state buffer with two independent active-low output enables (OEa and OEb). Each enable controls four buffered outputs (Ya0–Ya3 or Yb0–Yb3), which invert their respective inputs (Ia0–Ia3 or Ib0–Ib3) when enabled. When either OE is HIGH, its four outputs enter high-impedance state. This architecture supports flexible bus arbitration and memory addressing in TTL-based systems.

Does the N74F240N,602 support 5 V-only operation?

Yes, the N74F240N,602 is specified for VCC = 4.5 V to 5.5 V only. Its DC and AC characteristics - including input thresholds (VIL = 0.8 V, VIH = 2.0 V), output drive (–15 mA/64 mA), and propagation delay (4.3 ns typ) - are guaranteed only within this 5 V ±10% range. Operation outside this window violates recommended conditions and may cause timing violations or excessive ICC.

What is the pin configuration of the N74F240N,602?

The N74F240N,602 uses a 20-pin plastic DIP (SOT146-1) with GND at Pin 10 and VCC at Pin 20. Inputs Ia0–Ia3 occupy Pins 2–5; Ib0–Ib3 occupy Pins 12–15. Outputs Yb0–Yb3 are on Pins 3,5,7,9; Ya0–Ya3 on Pins 17,15,13,11. OEa is Pin 1; OEb is Pin 19. This layout matches industry-standard 74F240 pinouts and enables direct replacement in existing DIP sockets.

Can the N74F240N,602 drive multiple TTL loads directly?

Yes - each output of the N74F240N,602 can sink 64 mA or source 15 mA, exceeding standard TTL unit load requirements (1.0 U.L. = 0.6 mA LOW / 20 µA HIGH). With 750 U.L. fan-out capability in the LOW state, it can directly drive up to 10 standard 74LS inputs or equivalent loads without external buffers, simplifying board design in dense bus architectures.

Is the N74F240N,602 RoHS compliant?

The N74F240N,602 is a legacy part originally released in 2004 under pre-RoHS manufacturing standards. While not inherently RoHS-compliant due to leaded solder finish and Pb in die attach, Aetrix Electronics supplies only fully RoHS-compliant, lead-free reprocessed or equivalent-replacement stock meeting JEDEC J-STD-609 Class 2 requirements - verified via material declarations and XRF testing for each batch shipped.