STMicroelectronics M74HC597B1R

Overview

M74HC597B1R from STMicroelectronics is a high-speed CMOS 8-bit parallel-in/serial-out (PIPO) shift register with integrated storage latch, designed for data serialization in digital control and interface circuits. It features dual edge-triggered clocks (SCK for shift, RCK for load), asynchronous reset (SCLR), and operates across 2V–6V supply. Typical fMAX = 50 MHz at VCC = 6V, ICC ≤ 4 µA at TA = 25°C, and symmetrical 4 mA output drive support industrial bus buffering and LED driver staging.

For engineers reviewing the M74HC597B1R datasheet, M74HC597B1R pinout, M74HC597B1R application, or M74HC597B1R equivalent, key selection criteria include its dual-clock latch+shift architecture, 16-pin DIP package compatibility with 74-series 597 logic, propagation delay symmetry (tPLH ≅ tPHL), and wide temperature range (−55°C to +125°C) for embedded timing-critical systems.

Technical Context

The M74HC597B1R implements a two-stage synchronous register: an 8-bit parallel-load storage register feeding a serial-shift register, both triggered on rising edges of independent clocks (RCK and SCK). Its direct load (SLOAD active-low) and asynchronous clear (SCLR active-low) enable precise data capture and pipeline initialization without clock dependency.

Input protection diodes, 28% VCC noise immunity (VNIH/VNIL), and balanced |IOH| = IOL ≥ 4 mA output impedance ensure robust operation in noisy industrial environments. The device uses silicon gate C2MOS technology, delivering low static power (ICC ≤ 4 µA) while maintaining fast transitions (tTLH/tTHL ≤ 23 ns at VCC = 4.5 V).

Key Specifications

Pinout & Package

Package: Plastic DIP-16 (0.300", 3.94 mm body width), JEDEC MS-001 compliant, through-hole mountable with 2.54 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC597N and 74LV597PW, the M74HC597B1R offers superior temperature resilience (−55°C to +125°C), highest speed (50 MHz), and lowest quiescent current (4 µA), making it optimal for mission-critical automotive and industrial control where reliability trumps footprint or cost.

Availability

M74HC597B1R is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, LED matrix row driving, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for M74HC597B1R 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, specializing in automotive, industrial, and power management ICs with vertical manufacturing capability and AEC-Q100 qualification expertise.

The M74HC597B1R belongs to ST's high-speed HC logic family, engineered for pin-compatible upgrades of legacy 74-series devices in harsh-environment applications demanding extended temperature operation and low power.

FAQ

What is the function of the SLOAD pin on the M74HC597B1R?

SLOAD is an active-low parallel load enable input. When asserted low during a rising RCK edge, it transfers the 8-bit data present on pins A–H into the internal storage latch. This data remains held until shifted out serially via SCK, enabling precise separation between data capture and serialization timing.

Can the M74HC597B1R operate at 3.3 V supply?

Yes - the M74HC597B1R is fully specified for VCC = 2 V to 6 V, including 3.3 V operation. At 3.3 V, VIH = 2.31 V (70% VCC), VOL ≤ 0.26 V at 4 mA load, and fMAX ≈ 35 MHz, making it compatible with mixed-voltage 3.3 V/5 V systems without level-shifting.

Is the QH' output inverted, and why is that useful?

Yes, QH' is the inverted output of the final shift register stage. This inversion allows direct connection to active-low reset inputs or enables parity generation in daisy-chained configurations. It also simplifies feedback loop design where complementary logic states are required without external inverters.

Does the M74HC597B1R require external pull-up resistors on control inputs?

No - all inputs (SCLR, SLOAD, SCK, RCK, SI, A–H) have built-in protection diodes and defined VIH/VIL thresholds. Pull-ups are unnecessary unless specific system-level noise immunity or default-state requirements dictate otherwise; unused inputs should be tied to VCC or GND.