Pin Header Types & Sizes Explained

The term "header" can have various meanings depending on the context. It could refer to the information at the beginning of a block of data, an automotive component, or even a way to strike a soccer ball. In this case, however, we are focusing on pin headers and corresponding female headers, which are used to connect small wires to circuit boards. These are sometimes called "Berg connectors," named after the company that manufactures this type of device.

Pin Header Connector Basics

Pin headers are stiff metallic connectors that are soldered to a circuit board and stick up to receive a connection from a female socket. While pin headers (often called PH, or headers) are male by definition, female equivalents are also quite common, and we refer to them as female headers (FH) or header connectors.

A plastic structure holds the pin headers together, often designed to snap apart when needed. Female headers, however, are typically manufactured with a fixed number of pins.

Headers are defined by:

1. The number of pins in a row.

2. An "x."

3. The number of rows.

For example, an 8x2 header means there are eight pins in a row with two rows of pins, totaling 16 connections.

Headers are also characterized by the spacing (pitch) between the pins, with 2.54mm (0.1in) being the most common. Other sizes, such as 1.27mm (0.05in) or 2.00mm (0.079in), are also available. Most headers are through-hole devices, although surface-mount technology (SMT) headers are also available. While straight headers are standard, 90-degree pin headers are commonly used to meet specific physical requirements.

Types of Pin Headers

1. Single Row Pin Headers

Single row pin headers are the most common and widely used pin headers. These headers consist of a single row of pins and are typically used when there is only a need for a straightforward, single connection. Single-row headers are often used for low-density applications and are available in a variety of pin counts, ranging from 2 pins to 40 or more.

Key Features:

- Standard configurations: 2, 3, 4, 5, 6, 8, 10, 12, 14, etc.

- Pitch (distance between pins): Common pitches include 2.54mm (0.1 inch), but smaller or larger pitches may also be available.

2. Dual Row Pin Headers

Dual row pin headers consist of two parallel rows of pins, providing more connection options in a compact space. These headers are often used in applications that require a higher number of pins, such as microcontroller connections, multi-pin sensors, or bus connections.

Key Features:

- Common pin counts: 10, 20, 30, 40, etc.

- Pitch options: 2.54mm or 1.27mm (for finer pitch).

- Ideal for higher-density connections.

3. Right-Angle Pin Headers

Right-angle pin headers are a variation where the pins are set at a 90-degree angle from the header’s base. These headers are ideal when you need the pins to connect to the PCB horizontally rather than vertically, providing flexibility for space-limited designs.

Key Features:

- Pin orientation: 90-degree angle for sideways connections.

- Compact and space-saving: Ideal for designs where vertical height is constrained.

4. Surface Mount Pin Headers

Surface mount pin headers are designed to be soldered directly onto the surface of a PCB, rather than through holes. This type of header is used in compact and high-density designs, as it offers a lower profile and can save PCB space. Surface mount pin headers are often used in modern electronic devices, including mobile phones, laptops, and other consumer electronics.

Key Features:

- Low profile: Ideal for applications where height is limited.

- Mounting type: Soldered directly to the PCB surface.

- Common pitches: 1.27mm, 2.54mm, or finer.

5. Shrouded Pin Headers

Shrouded pin headers are pin headers that feature a plastic housing surrounding the pins. The housing helps prevent accidental short circuits by ensuring that only the correct pins make contact. Shrouded headers are especially useful in situations where the header will be used for connecting or disconnecting cables or other components.

Key Features:

- Plastic housing: Provides additional protection and alignment.

- Prevent accidental connections: Reduces the risk of improper connections.

Pin Header Sizes

1. Pin Pitch

The pin pitch refers to the distance between the centers of adjacent pins. This measurement is typically expressed in millimeters (mm) or inches. The most common pin pitch for pin headers is 2.54mm (0.1 inch), which is used for standard through-hole headers. However, pin headers also come in smaller pitches such as 1.27mm, 1.0mm, and even 0.5mm, depending on the design requirements.

Common Pin Pitches:

- 2.54mm (0.1 inch): The standard for most headers, suitable for general applications.

- 1.27mm: Often used for higher-density connections.

- 1.0mm: Common in compact designs, such as laptop motherboards.

- 0.5mm: Used in ultra-compact and high-density applications.

2. Pin Length

The pin length refers to how long the metal pins extend from the header. Pin length can vary depending on the header design, the thickness of the PCB, and the type of connector being used. The standard pin length for most headers is around 10mm, but pin lengths can range from just a few millimeters for surface-mount types to 30mm or more for larger, through-hole headers.

Pin Length Variations:

- Short pins: Used for surface-mount or low-profile headers.

- Medium pins: Typically used for standard through-hole connectors.

- Long pins: Often used in right-angle or extended connectors for PCB mounting.

3. Pin Count

Pin headers come with varying numbers of pins, allowing you to select the one that best fits the number of connections required. Single-row headers can have as few as two pins, while dual-row headers typically start at 10 pins and can go up to 40 or more.

Typical Pin Counts:

- Single-row headers: 2 to 40 pins.

- Dual-row headers: 10 to 40+ pins.

Choosing the Right Pin Header

When selecting the appropriate pin header, several factors must be considered:

1. Application Type: Determine if the connection needs to be vertical or horizontal, as this will guide the choice between standard, right-angle, or surface-mount headers.

2. Pin Count: Ensure the pin header provides the correct number of pins for your circuit connections.

3. Space Constraints: For compact designs, consider surface-mount or right-angle pin headers with smaller pin pitches.

4. Environmental Conditions: In harsh environments, shrouded pin headers can offer additional protection against accidental short circuits.

Conclusion

Pin headers are a versatile and essential component in the world of electronics, available in a variety of types, sizes, and configurations. By understanding the differences between the various pin header types and sizes, you can ensure that your electronic designs are both functional and reliable. Whether you’re working with a simple circuit board or a complex microcontroller project, choosing the right pin header will provide the connections needed for optimal performance.