BD442S

Overview

The BD442S is a PNP silicon epitaxial planar transistor manufactured by onsemi, designed for through-hole mounting in TO-126 packages. It operates with a maximum collector current of 4 A and withstands collector-emitter voltages up to 80 V. The device features a power dissipation rating of 36 W and a transition frequency of 3 MHz. It supports an operating temperature range from -55°C to +150°C junction temperature. Key electrical characteristics include a collector-base voltage of 80 V, emitter-base voltage of 5 V, and a saturation voltage of 800 mV at specified currents.

Feature Summary

• PNP polarity configuration suitable for high-current switching applications
• Robust thermal performance with 36 W power dissipation capability
• High voltage tolerance supporting 80 V collector-emitter operation

Applications

• General-purpose switching circuits
• Power supply output stages
• Motor control interfaces

Procurement Notes

Verify the exact suffix against official datasheets as variations exist within the family. Confirm RoHS compliance status and material declarations directly with the manufacturer or authorized distributors. Ensure the package type matches the required PCB footprint before ordering. Check for obsolescence notices or lifecycle changes that may affect long-term availability.

Selection Notes

Select this component when a single PNP transistor with 4 A continuous current capacity is required. The TO-126 package provides adequate heat sinking for moderate power levels. Compare hFE gain requirements against specific circuit needs, as minimum gain values vary between package variants. Ensure the application voltage does not exceed the 80 V breakdown limits under all operating conditions.

Part Context

This part belongs to the BD442 series of bipolar junction transistors. It shares core electrical specifications with other variants like BD442G but differs in packaging and specific manufacturing lot details. The series is widely used in industrial and consumer electronics for power handling tasks requiring reliable PNP switching capabilities.

Replacement Considerations

BD442G is a verified substitute with identical electrical ratings but utilizes a TO-126 package variant. Verify pinout compatibility and thermal resistance differences before substitution. Other PNP transistors with matching 4A/80V ratings may require circuit adjustments.