BD179

Overview

The BD179 is an obsolete NPN silicon power transistor manufactured by STMicroelectronics. It utilizes planar technology with a base island layout to deliver high gain and low saturation voltage. The device is housed in a SOT-32 (TO-126) package. Key electrical ratings include a collector-emitter voltage of 80 V, a continuous collector current of 3 A, and total dissipation of 30 W at 25°C case temperature.

Feature Summary

• Planar technology with base island layout
• High DC current gain performance
• Low collector-emitter saturation voltage

Applications

• General purpose switching applications

Procurement Notes

Verify the component status as obsolete before procurement planning. Confirm availability through authorized distributors or secondary markets. Ensure compatibility with existing designs requiring the SOT-32 package. Review datasheet specifications for absolute maximum ratings to prevent operational failure during integration.

Selection Notes

Select this component only if the design specifically requires the 80 V rating and 3 A current capacity within a TO-126 form factor. Evaluate alternative active components if supply chain continuity is critical. Consider thermal management requirements based on the 30 W dissipation limit at specified case temperatures.

Part Context

This part belongs to STMicroelectronics' legacy range of medium power linear and switching transistors. It was designed for general-purpose applications utilizing complementary circuits. The product has been superseded by newer generations offering improved efficiency and packaging options.

Replacement Considerations

Check for direct pin-compatible replacements from other manufacturers such as Motorola or Fairchild that match the 80V/3A specification. Verify that any substitute maintains the same SOT-32 footprint and electrical characteristics.