Nexperia USA Inc. 74HCT259DB,118

Overview

74HCT259DB,118 from Nexperia is an 8-bit addressable latch with TTL-compatible inputs, operating from 4.5 V to 5.5 V, supporting four functional modes (addressable latch, memory, 3-to-8 demultiplexing, and reset), and delivering 4.32 V VOH at 4.0 mA load - used in industrial I/O expansion and address decoding for microcontroller peripheral interfaces.

For engineers reviewing the 74HCT259DB,118 datasheet, 74HCT259DB,118 pinout, 74HCT259DB,118 application, or 74HCT259DB,118 equivalent, key selection factors include its active-LOW latch enable (LE) and master reset (MR), TTL-level input compatibility, SO16 package thermal profile, and guaranteed operation from –40 °C to +125 °C.

Technical Context

The device implements a dual-function architecture: a parallel-access 8-bit latch array controlled by A0–A2 address lines and LE/MR control logic, plus a dedicated 3-to-8 decoder path activated when MR = LOW and LE = LOW. Its mode selection relies on static logic levels at LE and MR - no clock required - enabling deterministic state transitions without timing constraints on address setup relative to data.

Input clamping diodes allow safe interfacing to voltages exceeding VCC when current-limiting resistors are used. Output drive strength is asymmetrical: 4.0 mA sink (VOL = 0.26 V @ 5.2 mA) and 4.0 mA source (VOH = 3.98 V @ –4.0 mA), optimized for driving CMOS loads and legacy TTL inputs.

Key Specifications

Pinout & Package

SOT109-1 (SO16) plastic small outline package: 16-pin, 3.9 mm body width, 1.27 mm pitch, gull-wing leads, JEDEC MS-012 compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit addressable latch applications.

Compared with 74HC259DB,118 and SN74LS259N, the 74HCT259DB,118 uniquely balances TTL input compatibility, industrial temperature support, and low-power CMOS efficiency - making it optimal for new designs requiring robustness and interoperability without sacrificing speed or thermal margin.

Availability

74HCT259DB,118 is available at Aetrix Electronics and suitable for industrial I/O expansion, microcontroller address decoding, reset-synchronized peripheral control, and LED/display driver interface requiring stable component supply across extended temperature ranges.

Supply support for 74HCT259DB,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

Nexperia is a leading semiconductor manufacturer specializing in high-performance logic, analog, and MOSFET solutions, with a focus on reliability, energy efficiency, and automotive-grade qualification.

The 74HCT259 belongs to Nexperia's industry-standard 74-series logic family, designed specifically for robust, drop-in replacement of legacy TTL components in industrial and automotive control systems.

FAQ

What is the function of the MR (Master Reset) pin?

The MR pin is an active LOW asynchronous reset that forces all eight outputs (Q0–Q7) to LOW regardless of LE, address, or data state. It overrides all other modes and requires no clock or enable signal. When MR is held HIGH, the device operates normally in addressable latch, memory, or demux mode depending on LE state. This pin ensures deterministic power-up or fault-recovery behavior in safety-critical systems.

Can 74HCT259DB,118 operate with a 3.3 V supply?

No - the 74HCT259DB,118 is specified only for 4.5 V to 5.5 V operation. Its TTL-compatible inputs require VIH ≥ 2.0 V, but internal circuitry is not characterized below 4.5 V. For 3.3 V systems, use the 74HC259DB,118 variant, which supports 2.0–6.0 V and has CMOS-level inputs compatible with 3.3 V logic thresholds.

How does the addressable latch mode differ from demultiplexer mode?

In addressable latch mode (MR = HIGH, LE = LOW), the addressed Qn output follows D while others retain prior states. In demultiplexer mode (MR = LOW, LE = LOW), only the addressed Qn follows D and all others are forced LOW - effectively acting as a 1-of-8 selector. The key distinction is retention vs. zeroing of non-selected outputs, determined solely by MR level.

Is the SO16 package RoHS-compliant and lead-free?

Yes - the SOT109-1 (SO16) package used for 74HCT259DB,118 is fully RoHS-compliant and lead-free, meeting EU Directive 2011/65/EU and Nexperia's environmental policy. The device carries the "Pb-free" marking and is qualified for reflow soldering per J-STD-020, with peak temperature tolerance up to 260 °C.