NXP Semiconductors 74HC259DB,112

Overview

74HC259DB,112 from Nexperia is an 8-bit addressable latch IC with four operational modes: addressable latch, memory, 3-to-8 demultiplexing, and reset. It features CMOS-level inputs, operates from 2.0 V to 6.0 V, supports -40 °C to +125 °C ambient range, and delivers 37 ns typical propagation delay (VCC = 4.5 V). It is used in digital logic control systems requiring selective parallel output updating via 3-bit address decoding.

For engineers reviewing the 74HC259DB,112 datasheet, 74HC259DB,112 pinout, 74HC259DB,112 application, or 74HC259DB,112 equivalent, key selection considerations include its dual-mode functionality (latch + decoder), active-low LE/MR control logic, SO16 package compatibility, and TTL-compatible 74HCT259 variant availability for mixed-signal interfacing.

Technical Context

The device implements a combinational address decoder feeding eight independent D-type latches, enabling random-access write to any single Qn output while preserving others' states. Its mode selection is determined solely by the logic levels of LE and MR pins per Table 4 - no internal state machine or clock domain crossing is involved.

All outputs are push-pull with ±25 mA drive capability, input clamping diodes allow overvoltage-tolerant interfacing, and ESD protection meets HBM >2000 V and CDM >1000 V. The functional diagram confirms direct routing from D/A0–A2 to Q0–Q7 with no internal feedback or storage beyond the latch array.

Key Specifications

Pinout & Package

74HC259DB,112 uses the SO16 (SOT109-1) plastic small outline package: 16-pin, 3.9 mm body width, 1.27 mm lead pitch, gull-wing leads. Pin 1 index located at top-left corner with notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC259DB,112, the 74HCT259DB,112 offers improved input threshold compatibility with older 5 V logic but shares identical timing and drive strength; SN74HC259N provides mechanical flexibility at the cost of higher board area and reduced high-frequency noise immunity.

Availability

74HC259DB,112 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, LED matrix row driving, automotive body control modules, and automated test equipment signal routing requiring stable component supply across extended temperature ranges.

Supply support for 74HC259DB,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 focused on essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74HC259 belongs to Nexperia's HC logic family - designed for low-power, high-noise-immunity digital control in space-constrained, thermally demanding applications where reliability across wide voltage and temperature ranges is mandatory.

FAQ

What is the difference between 74HC259DB,112 and 74HCT259DB,112?

The 74HC259DB,112 uses CMOS-level input thresholds (VIH ≥ 3.15 V at VCC = 4.5 V), while the 74HCT259DB,112 uses TTL-compatible thresholds (VIH ≥ 2.0 V). Both share identical pinout, timing, output drive, and package. Choose HC for pure CMOS systems and HCT for mixed 5 V TTL/CMOS interfaces.

Can 74HC259DB,112 operate reliably at 2.0 V supply?

Yes - it is fully specified down to 2.0 V supply, with VIH = 1.5 V min and VOL = 0.1 V max at 4.0 mA load. Propagation delay increases to 185 ns (typ) at 2.0 V, making it suitable for low-power sensor nodes and battery-operated devices where speed is secondary to energy efficiency.

How does the reset (MR) pin interact with latch enable (LE)?

MR is asynchronous and dominant: when MR = LOW, all Qn outputs force LOW regardless of LE, A0–A2, or D state. LE only controls latching when MR = HIGH. This allows hard reset override during fault conditions without requiring precise timing coordination with LE.

Is thermal pad soldering required for SO16 package (SOT109-1)?

No - the SO16 package has no exposed thermal pad. Thermal dissipation relies on copper pour under pins 8 (GND) and 16 (VCC) and standard PCB trace width design. For 500 mW max power, use ≥ 250 mm² 2-oz copper area connected to GND/VCC planes.