Nexperia USA Inc. 74HC597D-Q100J

Overview

74HC597D-Q100 from Nexperia is an AEC-Q100 Grade 1 qualified 8-bit parallel-in, serial-out shift register with input flip-flops, featuring dual positive-edge-triggered clocks (STCP for storage, SHCP for shifting), asynchronous master reset (MR), and parallel load (PL). It operates from 2.0 V to 6.0 V across −40 °C to +125 °C and is used in automotive body control modules for serializing sensor or switch inputs into microcontroller GPIOs.

For engineers reviewing the 74HC597D-Q100 datasheet, 74HC597D-Q100 pinout, 74HC597D-Q100 application, or 74HC597D-Q100 equivalent, this device supports robust serial data acquisition in electric power steering ECUs, HVAC control panels, and lighting control units where latch timing integrity, noise immunity, and automotive-grade reliability are critical.

Technical Context

The device integrates two synchronized but functionally independent registers: an 8-bit parallel input storage register clocked by STCP, and a serial-shift register clocked by SHCP. Data transfers from storage to shift register occur on PL low, while MR low asynchronously clears the shift register - both operations are edge-independent of SHCP.

Input clamping diodes enable safe interfacing to voltages exceeding VCC when used with current-limiting resistors. CMOS-level inputs (VIH ≥ 3.15 V at VCC = 4.5 V) ensure compatibility with 3.3 V and 5 V logic domains, and propagation delays (e.g., 20 ns typ. SHCP-to-Q at VCC = 4.5 V, CL = 50 pF) support >24 MHz operation in high-speed scan chains.

Key Specifications

Pinout & Package

74HC597D-Q100 uses the SO16 plastic small outline package (SOT109-1), 16-pin, 3.9 mm body width, with standard 1.27 mm pitch and gull-wing leads suitable for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit parallel-in, serial-out shift register applications.

Compared with 74HC597D-Q100, the 74HCT597D-Q100 offers easier integration into 5 V TTL systems but sacrifices CMOS noise margin, while the SN74HC165QPWRQ1 reduces control complexity at the expense of deterministic input capture timing and independent register staging.

Availability

74HC597D-Q100 is available at Aetrix Electronics and suitable for automotive body control units, industrial I/O expansion modules, LED matrix row drivers, and HVAC control panels requiring stable component supply with full AEC-Q100 traceability.

Supply support for 74HC597D-Q100 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 delivering high-performance, reliable logic, analog, and MOSFET solutions with focus on automotive, industrial, and mobile markets.

This device belongs to Nexperia's automotive-qualified HC logic family, designed specifically for robust serial data acquisition in harsh-environment electronic control units where timing precision, ESD resilience, and thermal stability are non-negotiable.

FAQ

What is the minimum pulse width required for SHCP and STCP to ensure reliable register updates?

The minimum SHCP and STCP pulse width is 14 ns at VCC = 6.0 V and 16 ns at VCC = 4.5 V, as specified in Table 7. These values guarantee proper edge detection and internal state transition across the full −40 °C to +125 °C temperature range. Shorter pulses may cause metastability or missed clock events, especially under worst-case voltage and temperature conditions.

Can MR and PL be asserted simultaneously, and what happens to the shift register state?

Yes, MR and PL can be asserted simultaneously. When MR is low, the shift register is asynchronously cleared (Q = LOW), overriding any PL action. The storage register remains unaffected, preserving its contents until STCP or subsequent PL assertion. This behavior is explicitly defined in Table 3's "invalid logic" row and ensures predictable reset during fault recovery sequences.

How does the input clamping diode functionality affect interfacing with 12 V automotive switch signals?

The integrated input clamp diodes allow direct connection of 12 V switch signals when paired with a series current-limiting resistor (e.g., 10 kΩ at VCC = 5 V yields ~0.7 mA forward current). This avoids external protection components while maintaining VIH/VIL thresholds - confirmed by the "Inputs include clamp diodes" statement in Section 1 and limiting values in Table 4 (IIK = ±20 mA).

Is there a recommended layout practice to minimize skew between STCP and SHCP signals in high-speed daisy-chain configurations?

Yes: route STCP and SHCP as matched-length, tightly coupled differential-like pairs (even though single-ended), maintain ≥2× trace spacing from noisy nets (e.g., power rails, motor drivers), and place 100 nF ceramic decoupling capacitors within 3 mm of VCC/GND pins. These practices mitigate inter-clock skew, which directly impacts setup/hold timing margins - validated by the 5 ns minimum tsu/th values in Table 7.