D-Sub Cable Assemblies

The Comprehensive Guide to D-Sub Cable Assemblies

D-Sub cable assemblies are vital components in various electronic and industrial applications and are known for their reliable performance and versatility. This guide delves into the essentials of D-Sub connectors, providing insights into their structure, applications, and how to select the right one for your needs.

What is a D-Sub Connector?

D-Sub, short for D-Subminiature, is a type of connector introduced in the 1950s by ITT Cannon. Recognizable by their distinct D-shaped metal shell, these connectors play a crucial role in connecting various devices, particularly in computing and telecommunications. The D-shaped shield ensures proper orientation and secure connections, preventing incorrect plug-ins and enhancing reliability.

Structure and Characteristics

D-Sub connectors typically consist of two main components: the plug (male) and the receptacle (female). Pins and sockets establish the connection, facilitating the transmission of video, audio, and digital signals. Additionally, this design includes multiple grounding points to reduce electromagnetic interference (EMI) and noise, ensuring signal integrity.

D-Sub Male to Female Cable, UL20276, 28AWG
D-Sub Male to Female Cable, UL20276, 28AWG

How D-Sub Connectors Work

D-Sub connectors transmit electrical signals via physical contact between the pins and sockets. Metal clips inside the sockets ensure a secure connection with the pins. Furthermore, the metal shield around the connector provides grounding and reduces EMI, ensuring signal integrity and reliability.

Types of D-Sub Cable Assemblies

Standard D-Sub Connectors: These are the most widely used and come in sizes ranging from 9 to 50 pins. They are commonly used in computer ports, such as serial and parallel connections.

High-Density D-Sub Connectors: These connectors have a higher pin count within the same shell size, making them ideal for applications requiring more connections in a compact space.

Mixed-Layout D-Sub Connectors: These allow for the inclusion of different types of contacts (signal, power, coaxial, etc.) within the same connector, offering great design flexibility.

Custom D-Sub Cables: These can be manufactured to meet specific requirements, including custom lengths, pinouts, and connector combinations.

Common D-Sub Connector Types and Models

D-Sub 9-Pin (DE-9):

  • Usage: Commonly used for serial communications.
  • Applications: Older computer serial ports and certain industrial equipment.

D-Sub 15-Pin (DA-15):

  • Usage: Often used for VGA connections.
  • Applications: Connecting monitors to computers and video equipment.

D-Sub 25-Pin (DB-25):

  • Usage: Used for parallel connections.
  • Applications: Older printer ports and industrial control systems.

Other Variants:

  • D-Sub 37-Pin (DC-37): Used in industrial and data acquisition applications.
  • D-Sub 50-Pin (DD-50): Suitable for complex interconnections in industrial settings.
Common Types of D-Sub Connectors
Common Types of D-Sub Connectors

Key Features and Benefits

  1. 360-Degree Shielding: High-quality D-Sub cables feature full shielding from the bulk cable to the connector shell, providing robust protection against electromagnetic interference (EMI). This is crucial for maintaining signal integrity in demanding environments.
  2. Durability and Reliability: D-Sub connectors are known for their mechanical strength and durability. They can withstand numerous mating cycles, making them suitable for applications that require frequent connections and disconnections.
  3. Variety of Materials and Platings: The connectors are available in different materials such as steel, brass, and stainless steel, as well as various plating options like gold, which enhance corrosion resistance and electrical performance.
  4. Waterproof and Non-Magnetic Options: IP67-rated waterproof and non-magnetic connectors are available for specialised applications, providing solutions for harsh or sensitive environments.
  5. Versatile Applications: D-Sub connectors are used in various applications, from connecting VGA displays and printers to older game consoles and computer mice. They are also essential in industrial equipment and telecommunications.

Applications of D-Sub Cable Assemblies

VGA Displays: VGA (Video Graphics Array) D-Sub cables connect PCs to monitors, transmitting analogue video signals.

Serial and Parallel Ports: D-Sub cables often enable data communication with peripherals like printers and modems through RS-232 serial and parallel computer ports.

Gaming Consoles: Older gaming systems from the 1980s and 1990s frequently use D-Sub connectors for their controllers and other peripherals.

Industrial Equipment: D-Sub connectors are widely used in industrial settings for robust data and signal transmission, ensuring reliable performance under challenging conditions.

Telecommunications: These connectors are integral in telecommunications equipment, facilitating secure and efficient data transfer.

Choosing the Right D-Sub Connector

Selecting the appropriate D-Sub connector involves considering several factors:

Purpose and Requirements

First, understand the specific needs of your application, such as the type of signals being transmitted and the required number of connections.

Quality and Reliability

Ensure the connector meets industry standards and is manufactured by reputable brands to guarantee durability and performance.

Performance and Features

Consider the performance characteristics, including signal integrity, EMI shielding, and the physical robustness of the connector.

Assembly Options

D-Sub cable assemblies come in two main types:

  • Pre-Assembled Cables: Convenient and ready to use.
  • Field-Assembly Cables: Allow for customization and on-site adjustments.


D-Sub connectors are crucial in various electronic and industrial applications due to their reliability and versatility. Understanding the different types and how to select the right one ensures optimal performance and connectivity. By considering factors such as purpose, quality, and performance, you can make informed decisions for your specific needs.

Whether connecting a computer to a monitor, setting up an industrial automation system, or ensuring reliable data communication, D-Sub connectors provide a robust solution. Their enduring presence in the electronics industry attests to their reliability and functionality, making them an essential component in many modern applications.

Romtronic is a trusted supplier of high-quality D-Sub cables. Our extensive inventory and customization options ensure that you can find or create the perfect D-Sub cable assembly for your project.