Catalog / Electronic Components - Connectors Cheatsheet

Electronic Components - Connectors Cheatsheet

A quick reference guide to various electronic connectors, their types, applications, and key specifications.

Connector Basics and Types

Connector Fundamentals

Connectors are essential components used to join electrical circuits mechanically and electrically. They allow for modularity, easy assembly, and disconnection for maintenance or upgrades.

Key characteristics include:

  • Contact Resistance: The resistance to current flow at the point of contact. Lower is better.
  • Current Rating: Maximum current the connector can handle without overheating.
  • Voltage Rating: Maximum voltage the connector can safely handle.
  • Durability: Number of mating cycles the connector can withstand.
  • Environmental Resistance: Ability to withstand temperature, humidity, vibration, and other environmental factors.

Wire-to-Board Connectors

Header Connectors

Male pins designed to mate with female connectors. Common in PCB connections.

Housing Connectors

Female connectors that accept the header pins. Wires are crimped or inserted into the housing.

Example Applications

Connecting sensors, power supplies, and other peripherals to a PCB.

Board-to-Board Connectors

Stacking Connectors

Allow PCBs to be stacked on top of each other. Useful for high-density applications.

Edge Connectors

Connect a PCB edge directly into a slot or receptacle.

Example Applications

Connecting daughterboards to a mainboard, or memory modules to a motherboard.

Wire-to-Wire Connectors

Crimp Connectors

Wires are mechanically crimped to the connector. Require a crimping tool.

Insulation Displacement Connectors (IDC)

Wires are pressed into the connector, piercing the insulation to make contact. Fast and easy to use.

Example Applications

Joining wires in automotive wiring harnesses, appliances, and communication equipment.

Common Connector Types and Applications

USB Connectors

USB Type-A

Standard rectangular connector. Commonly used for connecting peripherals to computers.

USB Type-B

Square or trapezoidal connector. Used for connecting printers and other devices.

USB Type-C

Reversible connector. Becoming the standard for modern devices, offering faster data transfer and power delivery.

Mini-USB / Micro-USB

Smaller versions of USB. Previously common in mobile phones and other portable devices.

Audio/Video Connectors

3.5mm Audio Jack

Commonly used for headphones and microphones.

RCA Connectors

Used for composite video and stereo audio. Typically color-coded (yellow for video, red and white for audio).

HDMI Connectors

High-Definition Multimedia Interface. Used for transmitting high-quality video and audio signals.

DisplayPort

Another digital display interface, similar to HDMI but often used in computer monitors and graphics cards.

Power Connectors

Barrel Connectors

Used for connecting power supplies to devices. Common in consumer electronics.

Molex Connectors

Used for connecting power supplies to computer components (e.g., hard drives, CD-ROM drives).

ATX Power Connectors

Used to supply power to computer motherboards.

Network Connectors

RJ45 Connectors

Used for Ethernet connections. Common in computer networks.

RJ11 Connectors

Used for telephone connections. Smaller than RJ45 connectors.

Connector Specifications and Considerations

Key Electrical Specifications

Voltage Rating: The maximum voltage that the connector can safely handle. Exceeding this rating can lead to arcing or insulation breakdown.

Current Rating: The maximum continuous current that the connector can carry without overheating. Consider ambient temperature and duty cycle.

Contact Resistance: The resistance at the point of contact between the connector halves. Low contact resistance ensures minimal voltage drop and power loss.

Mechanical Considerations

Mating Cycles (Durability)

The number of times a connector can be mated and unmated before its performance degrades.

Retention Force

The force required to disconnect the connector. Should be sufficient to prevent accidental disconnections.

Connector Size and Footprint

Consider the available space and mounting options when selecting a connector.

Environmental Factors

Temperature Range

The operating temperature range of the connector. Important for applications in extreme environments.

Humidity Resistance

The ability of the connector to withstand high humidity levels without corrosion or degradation.

Vibration and Shock Resistance

The ability of the connector to maintain a reliable connection under vibration and shock conditions.

IP Rating

Ingress Protection rating. Indicates the level of protection against dust and water.

Connector Materials

Contact Materials: Common materials include brass, bronze, and copper alloys, often plated with gold or tin to improve conductivity and prevent corrosion.

Housing Materials: Typically made of plastic (e.g., nylon, PBT, polycarbonate) or metal (e.g., aluminum, stainless steel). The choice of material depends on the required strength, temperature resistance, and chemical resistance.

Connector Selection Guide

Selection Criteria

When selecting a connector, consider the following factors:

  • Application: What is the connector being used for?
  • Signal Type: Analog, digital, power, or data?
  • Voltage and Current Requirements: What are the maximum voltage and current levels?
  • Environmental Conditions: What are the operating temperature, humidity, and vibration levels?
  • Size and Space Constraints: What is the available space for the connector?
  • Mating Cycles: How many mating cycles are required?
  • Cost: What is the budget for the connector?

Connector Standards

UL (Underwriters Laboratories)

Safety standards for electrical components.

CSA (Canadian Standards Association)

Similar to UL, but for the Canadian market.

RoHS (Restriction of Hazardous Substances)

Limits the use of hazardous materials in electronic equipment.

REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

European Union regulation concerning the safe use of chemicals.

Troubleshooting Common Connector Issues

Poor Contact: Check for loose connections, corrosion, or damaged contacts. Clean contacts with a suitable cleaner.

Intermittent Connections: Caused by vibration, thermal expansion, or loose contacts. Secure the connector and check for damage.

Overheating: Caused by excessive current or high contact resistance. Reduce current or replace the connector with a higher-rated one.

Signal Degradation: Caused by impedance mismatch or poor shielding. Use shielded connectors and proper termination techniques.