BD437G

Overview

The BD437G is a silicon epitaxial-base NPN power transistor manufactured by onsemi. It is housed in a TO-225-3 (TO-220) through-hole package and rated for a maximum DC collector current of 4 A. The device supports a collector-emitter voltage (VCEO) of 45 V and a collector-base voltage (VCBO) of 45 V, with an emitter-base voltage (VEBO) of 5 V. Power dissipation reaches 36 W, while the collector-emitter saturation voltage is specified at 800 mV. The gain-bandwidth product (fT) is 3 MHz, and the minimum DC current gain (hFE) is 30. Operating temperatures range from -55°C to +150°C.

Feature Summary

• Epitaxial base construction designed for medium power linear and switching applications
• High thermal stability supporting operation up to 150°C junction temperature
• Robust mechanical packaging suitable for high-current through-hole mounting

Applications

• Car-radio output stages
• Medium power linear circuits
• General purpose switching applications

Procurement Notes

Verify the specific datasheet revision and RoHS compliance status directly with onsemi or authorized distributors before integration. Confirm that the TO-225-3 package dimensions match your PCB footprint requirements. Ensure thermal management solutions are adequate for the 36 W power dissipation rating under your specific operating conditions. Check for any recent manufacturing transfers or assembly location changes that may affect part traceability.

Selection Notes

Select this component when designing circuits requiring an NPN power transistor with a 4 A continuous current capability and 45 V breakdown voltage. The BD437G serves as the complementary pair to the BD438G PNP transistor within the same series. Consider its 3 MHz transition frequency for audio frequency amplification tasks rather than high-frequency RF switching. Evaluate thermal resistance parameters if operating near the maximum power dissipation limit.

Part Context

The BD437G belongs to the BD43x series of complementary silicon power transistors produced by onsemi. This family includes NPN types (BD433, BD435, BD437) and corresponding PNP types (BD434, BD436, BD438). These devices share similar electrical characteristics and packaging styles, facilitating push-pull amplifier designs. The series is engineered for reliability in automotive and industrial environments where stable performance across wide temperature ranges is required.

Replacement Considerations

The BD438G is the direct complementary PNP counterpart within the same series. Other BD43x variants may offer different current or voltage ratings but require verification of pinout compatibility.