Nexperia USA Inc. 74AHCT594D,112

Overview

74AHCT594D,112 from Nexperia is an 8-bit serial-in, parallel-out shift register with independent storage register, TTL-compatible input thresholds (VIH = 2.0 V, VIL = 0.8 V), dual positive-edge clocks (SHCP and STCP), and active-low asynchronous resets (SHR, STR). It operates from 4.5 V to 5.5 V across –40 °C to +125 °C and supports cascading via Q7S output - used in LED matrix drivers and remote control data latching.

For engineers reviewing the 74AHCT594D,112 datasheet, 74AHCT594D,112 pinout, 74AHCT594D,112 application, or 74AHCT594D,112 equivalent, key selection criteria include TTL-level input compatibility, separate shift/storage clock timing, guaranteed 70 MHz max frequency at 5 V, and SO16 package thermal performance up to +125 °C ambient.

Technical Context

The device integrates two synchronous stages: an 8-bit shift register accepting serial data (DS) on SHCP rising edges, and an 8-bit D-type storage register loaded from the shift register on STCP rising edges. Both registers feature independent active-low asynchronous clears (SHR, STR), enabling precise stage reset without affecting the other register.

Input signals include Schmitt-triggered DS, SHCP, STCP, SHR, and STR for noise immunity; outputs Q0–Q7 are buffered CMOS with VOH ≥ 3.7 V / VOL ≤ 0.55 V at IO = ±8 mA. Q7S provides cascaded serial output, allowing daisy-chained expansion without external logic.

Key Specifications

Pinout & Package

74AHCT594D,112 uses the SO16 plastic small outline package (SOT109-1), 16-pin, 3.9 mm body width, with standard 1.27 mm lead pitch and gull-wing leads. Pin 1 index located at top-left corner; pin 8 = GND, pin 16 = VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74AHC594D,112 and SN74HC595DR, the 74AHCT594D,112 uniquely delivers TTL-level input compatibility, dual independent clocks, and hardware-cascadable Q7S - making it optimal for automotive and industrial designs requiring deterministic timing and robust noise immunity at 5 V.

Availability

74AHCT594D,112 is available at Aetrix Electronics and suitable for LED display drivers, industrial I/O expanders, remote control latching circuits, and automotive body control modules requiring stable component supply across extended temperature ranges.

Supply support for 74AHCT594D,112 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 efficiency, reliability, and miniaturization.

The 74AHCT series targets industrial and automotive applications needing TTL-compatible 5 V logic with enhanced noise immunity, wide temperature operation, and robust ESD protection - designed for mission-critical control and interface functions.

FAQ

Can 74AHCT594D,112 operate at 3.3 V supply?

No - the 74AHCT594D,112 is specified only for 4.5 V to 5.5 V operation. Its TTL-compatible inputs require VIH ≥ 2.0 V, but internal logic and output drive strength are not characterized below 4.5 V. For 3.3 V systems, use the pin-compatible 74AHC594D,112 instead, which supports 2.0–5.5 V.

What happens if SHCP and STCP are tied together?

When SHCP and STCP are connected, the shift register advances one bit on each clock edge before the storage register updates, causing Q0–Q7 to reflect the *previous* shift cycle's data. This creates a one-cycle pipeline delay - acceptable for simple streaming but unsuitable for applications requiring simultaneous shift-and-latch behavior.

Is Q7S output registered or combinatorial?

Q7S is a direct output of the final shift register stage (Q7), making it combinatorial relative to SHCP. It changes on the same SHCP rising edge that shifts data into stage 0, with propagation delay tPLH/tPHL ≤ 7.8 ns (CL = 50 pF, VCC = 5 V). No storage register buffering is applied.

How does SHR differ from STR in fault recovery?

SHR asynchronously clears only the shift register (resetting DS input path), leaving Q0–Q7 outputs unchanged. STR asynchronously clears only the storage register, forcing Q0–Q7 to LOW immediately. This separation allows safe reinitialization of incoming data flow without disrupting currently active outputs - critical in safety-monitored systems.