Nexperia USA Inc. 74AHCT594D-Q100,11

Overview

74AHCT594D-Q100 from Nexperia is an automotive-qualified 8-bit serial-in, parallel-out shift register with independent storage register, TTL-level inputs, and dual positive-edge-triggered clocks (SHCP and STCP). It features active-low asynchronous resets (SHR, STR), serial output Q7S for cascading, and operates from 4.5 V to 5.5 V across –40 °C to +125 °C. Used in automotive body control modules for LED driver expansion and multiplexed sensor interface.

For engineers reviewing the 74AHCT594D-Q100 datasheet, 74AHCT594D-Q100 pinout, 74AHCT594D-Q100 application, or 74AHCT594D-Q100 equivalent, key selection criteria include TTL-compatible input thresholds, independent shift/storage clock timing, AEC-Q100 Grade 1 qualification, SO16 package mechanical compatibility, and cascading capability via Q7S.

Technical Context

This device implements a two-stage pipeline: an 8-bit shift register accepting serial data on DS with SHCP, followed by an 8-bit D-type storage register loaded on STCP. Both registers support independent asynchronous reset (SHR/STR) and operate with Schmitt-trigger inputs for noise immunity.

The architecture enables precise timing separation-e.g., shift register updates one cycle ahead when SHCP and STCP are tied-making it suitable for synchronized data latching in distributed automotive I/O systems where setup/hold margins must be maintained across temperature and voltage extremes.

Key Specifications

Pinout & Package

74AHCT594D-Q100 uses the plastic small outline package SOT109-1 (SO16), 16-pin, 3.9 mm body width, with gull-wing leads and standard JEDEC MS-012 dimensions. Pin 1 index located at top-left corner with notch marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74AHC594D-Q100, the AHCT version offers guaranteed TTL input compatibility critical for legacy automotive ECUs, while SN74HC595QPWRQ1 sacrifices functional flexibility for cost reduction-making 74AHCT594D-Q100 optimal for new designs requiring robust timing control and fault resilience.

Availability

74AHCT594D-Q100 is available at Aetrix Electronics and suitable for automotive LED lighting control, body control module I/O expansion, and instrument cluster display multiplexing requiring stable component supply across extended temperature ranges and AEC-Q100 compliance.

Supply support for 74AHCT594D-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 components for automotive, industrial, and consumer markets, with leadership in logic, MOSFETs, and ESD protection.

The 74AHCT594D-Q100 belongs to Nexperia's automotive-qualified logic portfolio, engineered specifically for robust serial-to-parallel data conversion in harsh-temperature, high-reliability vehicle subsystems.

FAQ

Can SHCP and STCP be tied together in a single-clock configuration?

Yes, but doing so causes the shift register to always lead the storage register by one clock cycle. This behavior is documented in the functional description and verified in the timing diagram (Fig. 7). For predictable latched output, STCP should be delayed by one SHCP edge or driven separately to avoid metastability in time-critical applications.

What is the maximum capacitive load each Q0–Q7 output can drive reliably?

Each output is specified for ±8 mA at VCC = 4.5–5.5 V, supporting typical loads up to 50 pF with guaranteed timing (tPLH/tPHL ≤ 7.8 ns). Driving >100 pF requires external buffering; the datasheet confirms CL = 50 pF test condition for all dynamic parameters, and CI input capacitance is 10 pF max.

Does Q7S reflect the value before or after the latest SHCP edge?

Q7S reflects the value of internal stage Q6 *after* the most recent SHCP rising edge - i.e., it outputs the bit that was shifted out of Q6 during that transition. As confirmed in Fig. 6 and Table 3, Q7S changes on the same SHCP edge that advances the shift register, making it suitable for synchronous cascading without added latency.

How does the device behave when SHR and STR are both asserted low simultaneously?

Both registers reset independently: the shift register clears to all zeros, and the storage register clears Q0–Q7 to low. The function table (Table 3) explicitly defines "X ↑ L H" and "X ↑ H L" rows, confirming no interaction between SHR and STR - their effects are orthogonal and simultaneous, enabling coordinated fault-clear sequences in safety-critical firmware.