BD433S

Overview

The BD433S is an NPN epitaxial silicon power transistor manufactured by ON Semiconductor. It is housed in a TO-126 bulk package and designed for medium power linear and switching applications. The device features a collector-emitter voltage of 22 V, a continuous DC collector current rating of 4 A, and a peak collector current capability of 7 A. It supports a maximum collector dissipation of 36 W at a case temperature of 25°C. The component operates within a junction temperature range up to 150°C and includes a complementary PNP counterpart.

Feature Summary

• Designed for medium power linear and switching applications
• Complements the BD434 PNP transistor series
• Includes built-in overcurrent protection capabilities via safe operating area limits

Applications

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

Procurement Notes

Verify the specific ordering suffix against the official ON Semiconductor database, as Fairchild part numbers with underscores may have been converted to dashes during integration. Confirm the package type matches the required application, as the 'S' suffix denotes the TO-126 bulk packaging configuration. Ensure compliance with life support policies before deployment.

Selection Notes

Select this component when a 22 V NPN power transistor with a 4 A continuous current rating is required. Consider the complementary BD434 for push-pull configurations. Evaluate thermal management requirements carefully, as the 36 W dissipation rating is strictly dependent on maintaining a case temperature of 25°C. Verify that the application does not exceed the specified safe operating area boundaries.

Part Context

This component belongs to the BD433/435/437 family of NPN epitaxial silicon transistors originally developed by Fairchild Semiconductor. Following the corporate integration into ON Semiconductor, these devices continue to serve as standard solutions for automotive audio and general power electronics. The BD433 specifically provides the lowest voltage rating (22 V) within this matched set.

Replacement Considerations

• BD434 (Complementary PNP)
• BD435 (Higher Voltage Variant)
• BD437 (Highest Voltage Variant)

FAQ

What is the maximum collector-emitter voltage for the BD433S?

The maximum collector-emitter voltage (VCEO) for the BD433S is 22 V.

Is the BD433S suitable for use in life support systems?

No, ON Semiconductor products are not designed, intended, or authorized for use as critical components in life support systems or medical devices without express written approval.

What is the complementary PNP transistor for the BD433?

The BD434 is the complementary PNP transistor corresponding to the BD433 NPN device.