BD437

Overview

The BD437 is an NPN epitaxial silicon power transistor manufactured by onsemi. It features a maximum collector-emitter voltage (VCEO) of 45 V and a continuous collector current (IC) rating of 4 A. The device supports a collector dissipation of 36 W at a case temperature of 25°C and operates within a junction temperature range up to 150°C. It utilizes a TO-126 through-hole package with three terminals: emitter, collector, and base.

Feature Summary

• Designed for medium power linear and switching applications
• Complements the BD434, BD436, and BD438 PNP transistors
• Utilizes an NPN epitaxial silicon construction

Applications

• Medium power linear circuits
• Switching applications
• Car-radio output stages

Procurement Notes

Verify the specific ordering suffix against official documentation, as Fairchild Semiconductor part numbers containing underscores may have been converted to dashes during integration into ON Semiconductor systems. Confirm the exact package variant and packing method required for your assembly process before finalizing procurement.

Selection Notes

Select this component when a 45 V NPN power transistor with a 4 A DC collector current capability is required. Ensure the application design accommodates the 36 W power dissipation limit at 25°C case temperature and verify that the TO-126 package dimensions fit the intended PCB layout constraints.

Part Context

This device belongs to the BD433/BD435/BD437 series of NPN epixtal silicon transistors. It serves as the high-voltage counterpart in this family, complemented by the BD438 PNP type. The series is specifically engineered for robust performance in automotive audio and general-purpose power electronics.

Replacement Considerations

The BD435 is a lower voltage variant within the same series. Verify voltage ratings carefully if substituting. No direct cross-manufacturer equivalents are confirmed in the provided datasheet.