BD438STU

Overview

The BD438STU is a complementary PNP silicon epitaxial-base power transistor manufactured by onsemi. It belongs to the BD43x series, which includes NPN types such as the BD433, BD435, and BD437. The device is housed in a JEDEC SOT-32 plastic package. It is engineered for medium-power linear and switching applications, providing a matched complementary pair solution when used with its NPN counterpart.

Feature Summary

• Complementary PNP configuration designed to pair with specific NPN power transistors
• Epitaxial-base silicon construction for reliable performance
• JEDEC SOT-32 plastic package for standard mounting

Applications

• Medium power linear amplifier circuits
• Switching applications requiring complementary pairs
• Car-radio output stages (when paired with BD433)

Procurement Notes

Verify the exact suffix STU against official datasheets to confirm package type and tape/reel specifications. Ensure compatibility with the intended NPN complement (BD433/435/437) for balanced circuit performance. Check RoHS compliance status via the manufacturer's material composition declaration.

Selection Notes

Select this component when a PNP power transistor is required to match an existing NPN design using the BD43x series. Consider the SOT-32 package constraints for thermal management and board space. Verify that the medium-power rating aligns with the load requirements of the linear or switching application.

Part Context

The BD438STU is part of the BD43x family of complementary silicon power transistors. This family provides matched NPN/PNP pairs to simplify the design of push-pull output stages and other balanced circuits. The series is known for its use in audio and RF power amplification where symmetry between devices is critical.

Replacement Considerations

Direct replacements include other BD438 variants from different manufacturers offering identical pinouts and electrical characteristics. Ensure any substitute maintains the same SOT-32 package and complementary pairing capability with the corresponding NPN transistor.