NXP Semiconductors 74HCT259DB,112

Overview

74HCT259DB,112 from Nexperia is an 8-bit addressable latch with TTL-compatible inputs, operating from 4.5 V to 5.5 V, supporting four distinct modes (addressable latch, memory, 3-to-8 demultiplexing, and reset), and delivering 4.32 V VOH at 4.0 mA load in industrial temperature range (−40 °C to +125 °C) for use in programmable logic control I/O expansion.

For engineers reviewing the 74HCT259DB,112 datasheet, 74HCT259DB,112 pinout, 74HCT259DB,112 application, or 74HCT259DB,112 equivalent, this device serves as a serial-to-parallel interface with random-access data entry, active-HIGH 3-to-8 decoding, and common conditional reset - critical for microcontroller peripheral interfacing, LED matrix addressing, and address decoding in legacy bus systems.

Technical Context

The 74HCT259DB,112 implements a dual-function architecture: an 8-bit latch array controlled by A0–A2 address lines and LE/MR enable logic, plus integrated 3-to-8 decoder logic that routes D input to one of eight outputs based on address state. Its TTL-level inputs (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5.0 V) ensure direct compatibility with 5 V microcontrollers and legacy logic families.

Mode selection is determined solely by LE and MR pin states: LE = LOW + MR = HIGH enables addressable latching; LE = HIGH + MR = HIGH holds all outputs; LE = LOW + MR = LOW activates demultiplexing; LE = HIGH + MR = LOW forces all Qn outputs LOW. No internal clock or timing dependency exists - operation is purely combinatorial and level-sensitive.

Key Specifications

Pinout & Package

74HCT259DB,112 is supplied in SSOP16 (SOT338-1) package: plastic shrink small outline, 16 leads, body width 5.3 mm, 0.65 mm pitch. Pin 1 index located at top-left corner with beveled edge marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HCT373PW,118 and SN74HCT573N, the 74HCT259DB,112 uniquely integrates address decoding, conditional reset, and demultiplexing in a single SSOP16 footprint - enabling compact, feature-rich I/O expansion where mode flexibility and pin efficiency are essential.

Availability

74HCT259DB,112 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, LED matrix column driving, legacy bus address decoding, and microcontroller peripheral interface applications requiring stable component supply across extended temperature ranges.

Supply support for 74HCT259DB,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 specializing in high-performance logic, analog, and MOSFET solutions, with manufacturing rooted in process innovation and automotive-grade reliability standards.

The 74HCT259DB,112 belongs to Nexperia's 74HCT logic family - engineered for seamless integration with 5 V TTL systems, emphasizing low power, high noise immunity, and extended temperature operation in industrial control and automation.

FAQ

What is the maximum clock frequency supported by the 74HCT259DB,112?

The 74HCT259DB,112 has no internal clock - it is level-sensitive and edge-triggered on LE. Its usable toggle rate depends on propagation delay (22 ns LE→Qn) and setup/hold times (17 ns tsu, 0 ns th). With proper timing margins, it reliably supports address/data update cycles up to 20 MHz in addressable latch mode.

Can the 74HCT259DB,112 drive LEDs directly?

Yes - each Qn output delivers 4.0 mA sink/source capability (VOL = 0.26 V @ 5.2 mA, VOH = 3.98 V @ −4.0 mA). When used with appropriate current-limiting resistors (e.g., 220 Ω for 5 V supply), it can directly drive standard 20 mA LEDs in demultiplexer or latch mode without external drivers.

Is the MR (Master Reset) pin synchronous or asynchronous?

The MR pin is asynchronous: asserting MR = LOW immediately forces all Qn outputs LOW within tPHL = 23 ns (max), regardless of LE state, address inputs, or D value. Release (MR → HIGH) restores previous latch states or enables new updates - no clock or enable dependency is required.

Does the 74HCT259DB,112 support mixed-voltage operation (e.g., 3.3 V inputs with 5 V VCC)?

No - the 74HCT259DB,112 is strictly a 5 V device. Its TTL-compatible inputs require VIH ≥ 2.0 V, but VCC must be 4.5–5.5 V. Applying 3.3 V logic signals directly risks violating input thresholds and may cause metastability or increased ICC. A level shifter is required for 3.3 V MCU interfacing.