TO-257 Package

The TO-257 package is a compact transistor outline (TO) enclosure designed for semiconductor components such as transistors, thyristors, and integrated circuits. It features a metal body that offers effective protection and heat management. Slightly smaller than the TO-254, the TO-257 provides reliable performance in a more space-efficient design.

The TO-257 package is hermetically sealed to shield internal components from environmental factors like moisture and contaminants. This sealing is accomplished with glass and ceramic eyelets that insulate the leads from the metal body, ensuring consistent operation in various conditions. The metal casing aids in heat dissipation, preventing overheating in demanding applications.

Ideal for low lead count devices, the TO-257 is well-suited for applications where compact size and effective thermal management are crucial. It is commonly used in telecommunications, industrial electronics, and other high-reliability fields. The TO-257 balances performance and space, offering a cost-effective solution compared to larger packages such as the TO-254.

The TO-257 package typically features 3 leads with a standard pitch of around 1 inch (25.4 mm) square and 0.25 inches (6.35 mm) thick. Variants are available with different lead configurations and tables options, providing flexibility to meet specific application requirements.

At Electronic Products Inc. (EPI), we offer extensive customization options for the TO-257 package, including various lead configurations and plating materials such as nickel, copper, silver, and gold. As an ISO 9001:2015 certified manufacturer based in the US, we ensure that all our TO packages, including the TO-257, comply with RoHS and REACH standards, meeting stringent environmental and safety requirements.