STMicroelectronics M74HC595YRM13TR

Overview

M74HC595YRM13TR from STMicroelectronics is an automotive-grade 8-bit serial-in, parallel-out shift register with output latches and 3-state outputs, operating from 2 V to 6 V. It features dual independent clocks (SCK for shift register, RCK for storage register), asynchronous clear (SCLR), and QH' serial output for daisy-chaining. Typical fMAX = 59 MHz at VCC = 6 V, IOL/IOH ≥ 6 mA (QA–QH), and -40/+125 °C temperature range make it suitable for automotive LED matrix drivers and industrial I/O expansion.

For engineers reviewing the M74HC595YRM13TR datasheet, M74HC595YRM13TR pinout, M74HC595YRM13TR application, or M74HC595YRM13TR equivalent, key selection criteria include 3-state output control timing, SCLR asynchronous reset behavior, cascading capability via QH', and AEC-Q100 qualification for automotive environments.

Technical Context

The device integrates two synchronized but independently clocked registers: an 8-bit shift register accepting serial data on SI with positive-edge SCK, and an 8-bit D-type storage register loaded on positive-edge RCK. Outputs QA–QH are 3-state controlled by active-low G, enabling bus sharing without external logic.

It supports full cascading via QH' (serial output of last stage), allowing multi-device chains without additional buffering. The SCLR input asynchronously clears the shift register while leaving the storage register unaffected, supporting safe initialization sequences in safety-critical systems.

Key Specifications

Pinout & Package

SO16 package: 150 mil body width, 1.27 mm pitch, surface-mount TSSOP-compatible footprint with gull-wing leads. RoHS-compliant ECOPACK®2, tape-and-reel packaging (M13TR).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit shift register with storage latch applications.

Compared with SN74HC595PWR and 74LV595PW, M74HC595YRM13TR uniquely combines automotive temperature range, AEC-Q100 qualification, and proven robustness in high-noise environments-making it the only choice for safety-relevant vehicle subsystems where long-term parametric stability is mandatory.

Availability

M74HC595YRM13TR is available at Aetrix Electronics and suitable for automotive lighting control, industrial PLC output expansion, consumer appliance displays, and medical equipment indicator panels requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for M74HC595YRM13TR 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 microcontrollers, power ICs, sensors, and analog components for automotive, industrial, and consumer markets.

M74HC595YRM13TR belongs to ST's high-reliability HC logic family, engineered specifically for automotive and industrial applications demanding extended temperature operation, ESD robustness, and long-term parametric stability.

FAQ

Can M74HC595YRM13TR be used with 3.3 V microcontrollers?

Yes. Its VCC range of 2 V to 6 V supports direct connection to 3.3 V MCUs. Input thresholds scale with VCC (VIH ≥ 0.7×VCC), ensuring reliable logic recognition. Output VOH/VOL meet 3.3 V CMOS levels across temperature, eliminating level-shifter requirements in most designs.

What is the purpose of the QH' pin, and how does it differ from QA–QH?

QH' is the serial output of the shift register's eighth stage, providing the final bit before latching. Unlike QA–QH (which reflect the storage register state), QH' enables seamless cascading: connect QH' of one device to SI of the next to build arbitrary-length shift chains without external logic or timing compensation.

How does the asynchronous SCLR affect system initialization?

SCLR forces all shift register bits to logic 0 on its falling edge, independent of SCK or RCK. This allows deterministic clearing before first data load-critical in automotive systems where undefined startup states could cause unintended actuator activation. Storage register and outputs remain unaffected until RCK is pulsed.

Is thermal derating required for continuous operation at +125 °C?

Yes. At +125 °C, SO16 package power dissipation must be derated to 455 mW (−7 mW/°C from 500 mW at +65 °C). With typical ICC ≤ 40 μA and IOL/IOH ≤ 6 mA, self-heating remains negligible under normal drive conditions; however, simultaneous full-output loading at VCC = 6 V requires PCB copper area ≥ 250 mm² for safe operation.