Connectors & Headers
Connector
Electromechanical devices that join electrical circuits allowing disconnection, signal routing, or device attachment.
What it looks like
Connectors & Headers
A typical connector — exact shape, colour and markings vary between manufacturers.
Types & variants
Key specs
Current rating
Ampere (A)Max current the connector can handle continuously without overheating.
Voltage rating
Volt (V)Max voltage the connector can safely handle without arcing.
Poles
CountNumber of separate conductors/pins in the connector.
Pitch
mmDistance between adjacent pins (e.g. 2.54mm for standard headers).
Mating cycles
CountNumber of times the connector can be connected/disconnected before wear.
Markings
Often marked with manufacturer logo, part number, or pin count. Some have polarity indicators (triangle, dot).
Standard values
Pin counts: 1-100+. Common pitches: 1.25mm, 2.0mm, 2.54mm (0.1 inch). Standard pinouts: GPIO, UART, SPI, I2C.
How to choose
1) Match pin count and pitch to your PCB. 2) Check voltage/current requirements. 3) Ensure physical fit (board thickness, mounting). 4) Consider mating cycles for frequent use. 5) Verify locking mechanism if vibration is present.
Pinout & package
Pinout varies by type - check datasheet. Standard headers have 1:1 pin mapping. D-sub has specific pin assignments for signals/shield. USB has standard pinouts for power/data.
Example circuits
- PCB to module connection (e.g. Arduino to sensor)
- Power input/output connection
- Data communication between boards
- User interface connections (buttons, switches)
Common failures
Socket pins bend or break; contacts corrode or oxidize; plastic housing cracks; solder joints fail; loose connections from wear. Intermittent connections are a common symptom.
How to test
Visual inspection for bent/broken pins. With multimeter in continuity mode, check each pin connects to its mate. Check for shorts between adjacent pins.
Substitutes
Same pin count and pitch. Different mounting types (solder vs. press-fit) can sometimes be substituted. Ensure voltage/current ratings match or exceed.