BD649-S

Overview

The BD649-S is an NPN silicon power Darlington transistor manufactured by Bourns Inc., designed for high-current switching and amplification applications. It features a maximum collector current of 8A and a collector-emitter voltage rating of 100V, with a maximum power dissipation of 2W. The device offers a typical DC current gain (hFE) of 750 and operates within a junction temperature range of -65°C to 150°C. Packaged in a 3-pin TO-220 through-hole configuration, it provides robust performance for demanding electronic circuits.

Feature Summary

• NPN Darlington bipolar transistor architecture for high-gain amplification
• High collector current capability up to 8A for heavy load switching
• Wide operating temperature range supporting extreme thermal environments

Applications

• High-current switching circuits
• Power amplification stages
• Industrial control systems requiring robust transistor performance

Procurement Notes

Verify component status carefully as the BD649-S is listed as obsolete and no longer manufactured by Bourns Inc. Sourcing should focus on authorized distributors or verified surplus suppliers. Confirm that available units are genuine Bourns products and match the specified TO-220 package and electrical characteristics. Request original datasheets and traceability documentation to ensure quality and reliability before purchase.

Selection Notes

Select this component only if its specific 8A current rating and 100V voltage breakdown align precisely with circuit requirements. Consider the through-hole TO-220 mounting constraint during PCB layout. Evaluate thermal management needs due to 2W power dissipation. Since the part is obsolete, assess long-term availability risks and potential design modifications to accommodate replacement components if supply chain continuity is critical.

Part Context

The BD649-S belongs to the BDxxx-S series of NPN silicon power Darlington transistors from Bourns Inc. This series includes variants such as BD645-S and BD647-S, sharing similar architectural principles but differing in specific electrical ratings. The BD649-S specifically targets applications requiring higher current handling compared to lower-rated siblings in the same product family line.

Replacement Considerations

Public confirmed substitute part numbers are not explicitly provided in the source data. As the BD649-S is obsolete, engineers must identify equivalent NPN Darlington transistors with matching 8A/100V/TO-220 specifications from other manufacturers. Verify pinout compatibility and thermal characteristics when selecting alternatives.