pinouts

Pinout refers to the arrangement and labeling of the pins on a connector, header, or integrated circuit so that each pin corresponds to a specific signal, power, ground, or control function. A pinout describes which physical pin carries which electrical contact, and it is essential for making correct connections in electronic devices and systems.

Pinouts are used across devices and components, including external connectors (for example USB, HDMI, or automotive plugs), internal board headers (such as front-panel connectors on computers or servo controller interfaces), and the pads or pins of IC packages. The same connector family may have several variants with different pin assignments, so consulting the exact data sheet or a labeled diagram is important for compatibility.

Pinout information is typically presented as a diagram or table showing pin numbers alongside their functions. Numbering schemes vary by family, and viewing orientation matters: pin 1 is identified by a notch, bevel, or marker on the connector or component. Misreading a pinout can lead to nonfunctional equipment or damage from incorrect voltage or grounding.

Practitioners use pinouts during design, assembly, testing, and repair. Tools include manufacturer data sheets, continuity testers, multimeters, and logic analyzers. Understanding the pinout also helps in troubleshooting by tracing signals and ensuring that mating parts are correctly matched.

Related concepts include pin mapping, connector standards, and footprint design.