STMicroelectronics M74HC259YTTR

Overview

M74HC259YTTR from STMicroelectronics is an automotive-grade 8-bit addressable latch with active-low enable and conditional clear, operating from 2 V to 6 V. It features 3 address inputs (A/B/C), single data input (D), 8 latch outputs (Q0–Q7), and supports both latching and 3-to-8 decoding modes. With tPD = 20 ns (typ. at VCC = 6 V), ICC ≤ 4 µA (max. at TA = 25 °C), and AEC-Q100 qualified TSSOP16 packaging, it is used in automotive body control modules for LED driver addressing and I/O expansion.

For engineers reviewing the M74HC259YTTR datasheet, M74HC259YTTR pinout, M74HC259YTTR application, or M74HC259YTTR equivalent, this device requires attention to ENABLE/CLEAR timing margins, address setup/hold constraints (tS = 3 ns min. at VCC = 6 V), output drive capability (IOL = 4 mA min.), and automotive temperature range (-40 °C to +125 °C) compliance in safety-critical non-safety subsystems.

Technical Context

The M74HC259YTTR implements a silicon gate C2MOS-based addressable latch with dual-mode operation: when ENABLE is low, the addressed Qx follows D (latch mode); when ENABLE is high and CLEAR is low, all outputs reset to logic low. Its internal logic avoids bus contention by ensuring only one output changes per address transition.

It integrates ESD protection (HBM: 1.5 kV, CDM: 1 kV) and operates across full industrial voltage (2–6 V) with symmetrical output drive (|IOH| = IOL = 4 mA min.) and balanced propagation delays (tPLH ≈ tPHL). Input noise immunity is guaranteed at VNIH/VNIL ≥ 28 % VCC (min.), supporting robust operation in noisy automotive environments.

Key Specifications

Pinout & Package

TSSOP16 package: 4.9 mm × 6.4 mm × 1.2 mm body, 0.65 mm pitch, exposed pad not present, RoHS-compliant and ECOPACK® certified.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC259PWR and 74LVX259MTCX, the M74HC259YTTR uniquely combines AEC-Q100 qualification, full -40 °C to +125 °C operation, and dual-mode (latch/decoder) functionality with integrated CLEAR - making it the only choice for automotive body electronics requiring functional safety-adjacent reliability without ASIL certification.

Availability

M74HC259YTTR is available at Aetrix Electronics and suitable for automotive lighting control, body electronics modules, industrial I/O expansion, and consumer appliance panel interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for M74HC259YTTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and sensor solutions for automotive, industrial, and consumer markets.

The M74HC259YTTR belongs to ST's high-reliability HC logic family, engineered specifically for automotive body electronics and industrial control applications demanding extended temperature operation and robust EMC performance.

FAQ

What is the minimum ENABLE pulse width required for reliable latching at 6 V supply?

The minimum ENABLE low pulse width is 6 ns (typ.) and 20 ns (max.) at VCC = 6 V across -55 °C to +125 °C. Designers must ensure pulse width exceeds 20 ns under worst-case voltage and temperature conditions to guarantee data capture on the rising edge of ENABLE. This constraint is verified per Table 7 in the official ST datasheet DocID001933 Rev 2.

Can M74HC259YTTR operate as a standalone 3-to-8 decoder without external latching logic?

Yes - when ENABLE is held high and CLEAR is low, all outputs are forced low; when ENABLE is low, only the addressed output follows D while others remain latched. This behavior implements true 3-to-8 decoding with active-low enable, confirmed by Truth Table 3 and Functional Description Section 2 of the ST datasheet.

Does the CLEAR input affect outputs asynchronously or synchronously with ENABLE?

CLEAR operates asynchronously: asserting CLEAR low immediately forces affected outputs low regardless of ENABLE state. When ENABLE is high, all eight outputs clear; when ENABLE is low, only unaddressed outputs clear while the addressed output tracks D. This dual-mode behavior is explicitly defined in Table 3 and Section 2 of the ST datasheet.

Is the TSSOP16 package of M74HC259YTTR lead-free and RoHS compliant?

Yes - the M74HC259YTTR uses a lead-free, halogen-free TSSOP16 package compliant with RoHS Directive 2011/65/EU and ST's ECOPACK® environmental program. Package mechanical data in Table 10 and Section 4.2 of DocID001933 Rev 2 confirm Pb-free terminal finish and JEDEC-standard footprint.