BD249B-S

Overview

The BD249B-S is a silicon NPN power transistor manufactured by Bourns Inc., designed for high-current switching and amplification applications. It features an 80V collector-emitter voltage rating and a continuous collector current capacity of 25A. The device is housed in the SOT-93 (TO-220AB) package, which facilitates efficient heat dissipation. Key electrical characteristics include a maximum power dissipation of 125W at 25°C case temperature. The component operates within a junction temperature range of -65°C to 150°C, ensuring reliability under demanding thermal conditions.

Feature Summary

• High current handling capability with a 25A continuous collector current rating
• Robust thermal performance supporting up to 125W power dissipation
• Extended operating temperature range from -65°C to 150°C junction temperature

Applications

• Industrial motor control systems
• Power supply output stages
• High-power audio amplifier circuits

Procurement Notes

Verify the specific suffix 'S' against the manufacturer's latest datasheet to confirm package dimensions and pinout compatibility. Ensure that the procurement source provides valid RoHS compliance documentation as indicated in public listings. Cross-reference the part number with official Bourns catalogs to distinguish between standard and special processing variants before finalizing orders.

Selection Notes

Select this component when designing circuits requiring substantial current switching capabilities within an 80V limit. The SOT-93 package is suitable for board-level mounting where thermal management solutions, such as heatsinks, can be integrated. Evaluate the required DC current gain (hFE) ranges specified in the datasheet to ensure proper base drive design for saturation or linear operation modes.

Part Context

This part belongs to the BD249 series of bipolar junction transistors, widely utilized in power electronics. The BD249B variant specifically denotes the NPN configuration with defined voltage and current thresholds. The '-S' suffix typically indicates a specific packaging or tape-and-reel option, though verification with the manufacturer is required to confirm if it differs from the standard tube-packaged BD249B.

Replacement Considerations

Direct substitutes may include other NPN power transistors with comparable 80V/25A ratings in TO-220 packages, such as the MJ15003 or similar high-power BJT families. Always verify pinout compatibility and thermal resistance values ($R_{\theta JC}$) when replacing to maintain circuit integrity.