Diodes Incorporated 74AHCT164D14

Overview

74AHCT164D14 from Diodes Incorporated is an 8-bit serial-in/parallel-out edge-triggered shift register with asynchronous master reset, TTL-compatible inputs, Schmitt-trigger input action, and dual serial data inputs (DSA/DSB) logically ANDed for flexible enable/data control. It operates from 4.5V to 5.5V, delivers 8mA output drive at V_CC = 4.5V, and supports up to 125MHz clock frequency (CL = 15pF), commonly used in PC peripheral interface expansion and legacy parallel bus bridging.

For engineers reviewing the 74AHCT164D14 datasheet, 74AHCT164D14 pinout, 74AHCT164D14 application, or 74AHCT164D14 equivalent, key selection considerations include its asynchronous MR pin behavior, dual-input AND logic for serial data gating, guaranteed setup/hold timing (t_SU = 4.5ns, t_H = 2.0ns), and PDIP-14 package suitability for through-hole prototyping and industrial control backplanes.

Technical Context

The 74AHCT164D14 implements a synchronous 8-stage D-type flip-flop chain with positive-edge clock (CP) triggering and fully asynchronous active-low Master Reset (MR). Data enters Q0 from the ANDed DSA/DSB inputs on each CP rising edge, then propagates sequentially to Q1–Q7.

Its TTL-compatible inputs accept 2.0V VIH and 0.8V VIL thresholds, while Schmitt-trigger action ensures noise immunity on serial and clock lines. The device exhibits CMOS-level static power consumption (ICC ≤ 4.0μA typical at +25°C) and supports 15pF/50pF load conditions with t_PD ≤ 11.5ns max across –40°C to +125°C.

Key Specifications

Pinout & Package

74AHCT164D14 uses a 14-pin PDIP (Plastic Dual In-line Package) with 0.300-inch body width and 0.100-inch lead pitch, optimized for through-hole mounting on industrial control PCBs and evaluation fixtures.

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 SN74AHCT164N and 74LV164PW, the 74AHCT164D14 uniquely combines industrial-temperature-rated PDIP packaging, Schmitt-trigger noise immunity, and guaranteed 8mA drive at 4.5V-making it optimal for through-hole industrial control and retrofit applications where reliability trumps voltage flexibility.

Availability

74AHCT164D14 is available at Aetrix Electronics and suitable for PC peripheral expansion, industrial I/O modules, legacy bus interface, and LED display driver applications requiring stable component supply and long-term obsolescence management.

Supply support for 74AHCT164D14 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The 74AHCT164D14 belongs to Diodes' AHCT logic family-designed specifically for 5V TTL-to-CMOS interfacing with robust noise immunity, wide temperature operation, and drop-in compatibility with legacy 74-series logic in industrial control and infrastructure equipment.

FAQ

Can the 74AHCT164D14 operate reliably at 4.5V supply with full 8mA output drive?

Yes. Electrical Characteristics tables confirm VOL ≤ 0.36V at IOL = 8mA and VCC = 4.5V across –40°C to +85°C, and ≤ 0.55V up to +125°C. This meets TTL VOH/VOL compatibility requirements and ensures noise margins remain >0.7V under worst-case load and temperature.

What happens if both DSA and DSB are held HIGH during CP rising edge?

Per the Function Table and Logic Diagram, DSA and DSB are internally ANDed. When both are HIGH, the AND result is HIGH, so Q0 is set HIGH on the CP rising edge. This behavior is fully specified and usable for generating known startup states or test patterns without external logic.

Is the Master Reset (MR) pin truly asynchronous, and does it override clock and data inputs?

Yes. Note 5 and the Timing Diagram confirm MR is asynchronous: asserting MR LOW forces all Q0–Q7 LOW immediately, regardless of CP state, DSA/DSB levels, or previous register contents. Recovery requires MR HIGH for ≥t_rec = 2.5ns before the next CP edge to ensure stable operation.

Does the PDIP-14 package (D14) have the same timing specifications as SO-14 and TSSOP-14 variants?

Yes. All package variants (S14, T14, D14) share identical AC and DC electrical specifications per the datasheet's "Recommended Operating Conditions" and "Switching Characteristics" tables. Package differences affect thermal resistance and board-level EMI-not logic timing or voltage thresholds.