Diodes Incorporated 74HC164D14

Overview

74HC164D14 from Diodes Incorporated is an 8-bit serial-in/parallel-out shift register with asynchronous master reset, positive-edge-triggered clock, dual ANDed serial inputs (DSA/DSB), and eight buffered Q0–Q7 outputs in a 14-pin PDIP package. It operates from 2.0V to 6.0V, sinks/sources 4mA at V_CC = 4.5V, and supports up to 85MHz max clock frequency at 6.0V - used for LED driving, address expansion, and I/O port extension in embedded control systems.

For engineers reviewing the 74HC164D14 datasheet, 74HC164D14 pinout, 74HC164D14 application, or 74HC164D14 equivalent, key selection considerations include its dual serial input logic gating, asynchronous MR assertion timing (t_rec = 13ns min at 6.0V), output drive capability under load (V_OL = 0.26V at I_OL = 4mA), and compatibility with 5V TTL-level control interfaces.

Technical Context

The 74HC164D14 implements an edge-triggered shift register architecture where data enters Q0 on the rising edge of CP and propagates rightward (Q0→Q1→…→Q7) synchronously. Its dual serial inputs (DSA and DSB) are internally ANDed, enabling one pin to act as data and the other as enable - supporting gated serial loading without external logic.

Master Reset (MR) is asynchronous and forces all Q outputs LOW independently of CP or input states; recovery time t_rec = 13ns (min) at V_CC = 6.0V must elapse before the next CP edge. All inputs feature Schmitt-trigger action, ensuring noise immunity across slow-rising signals and wide V_CC operating range (2.0–6.0V).

Key Specifications

Pinout & Package

74HC164D14 is housed in a 14-pin Plastic Dual In-line Package (PDIP-14) with 0.3-inch body width and 0.1-inch lead pitch, suitable for through-hole prototyping and legacy PCB assembly.

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 SN74HC164N and 74HCT164N, the 74HC164D14 offers the lowest ICC across temperature, native dual-input gating flexibility, and Diodes' halogen-free compliance - making it optimal for cost-sensitive, low-power, and environmentally regulated industrial designs.

Availability

74HC164D14 is available at Aetrix Electronics and suitable for LED display drivers, microcontroller I/O expansion, printer head control, and industrial PLC output modules requiring stable component supply and long-term obsolescence management.

Supply support for 74HC164D14 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 analog ICs, specializing in high-reliability components for industrial, computing, and consumer applications.

The 74HC164D14 belongs to Diodes' HC logic family, designed for low-power, wide-voltage-range digital interfacing in space-constrained and thermally demanding environments.

FAQ

Can 74HC164D14 operate reliably at 3.3V supply?

Yes - the 74HC164D14 is fully specified from 2.0V to 6.0V. At V_CC = 3.3V, it delivers 4mA output drive, supports ≥45MHz max clock frequency, and maintains valid VIH/VIL thresholds (VIH = 2.31V min, VIL = 1.09V max). All AC/DC parameters are guaranteed across this range per DS36279 Rev. 2-2.

What happens if both DSA and DSB are left floating?

Leaving either DSA or DSB unconnected violates the recommended operating condition that unused inputs be tied to V_CC or GND. Floating inputs may cause erratic shifting due to noise coupling or partial turn-on of internal MOSFETs, leading to metastability or increased ICC. Tie unused serial inputs to V_CC to ensure predictable AND logic behavior.

Is the MR pin truly asynchronous, and does it affect propagation delay?

Yes - MR is fully asynchronous and overrides all internal state on assertion (LOW), forcing Q0–Q7 to LOW immediately, independent of CP or input levels. This action introduces no propagation delay dependency; t_PHL from MR to any Q is 11ns (max) at V_CC = 6.0V, as confirmed in the "Timing Characteristics" table on page 5 of DS36279.

Does 74HC164D14 support hot insertion or live circuit connection?

No - the 74HC164D14 lacks hot-swap protection features such as power-on reset, I²C bus arbitration, or slew-rate-limited inputs. Applying V_CC while signals are present may violate absolute maximum ratings (e.g., VI > V_CC + 0.5V), risking latch-up or permanent damage. Power sequencing per manufacturer guidelines is mandatory.