MC33981BHFK

Overview

The MC33981BHFK is a high-frequency, self-protected single high-side switch designed for automotive power management applications. It features a maximum on-resistance of 4.0 mΩ and supports PWM clock frequencies up to 60 kHz with duty cycles ranging from 5% to 100%. The device integrates comprehensive protection mechanisms including overcurrent, overtemperature, undervoltage shutdown, reverse battery protection, and fault reporting. Additional capabilities include slew rate control via an external capacitor, output current monitoring, temperature feedback, and a dedicated gate drive signal for an external low-side N-channel MOSFET.

Feature Summary

• Integrates self-protection features such as overcurrent, overtemperature, and undervoltage shutdown with fault reporting
• Supports high-frequency PWM operation up to 60 kHz with adjustable duty cycle
• Provides reverse battery protection and output current monitoring for system diagnostics
• Includes a gate drive signal interface for controlling an external low-side N-channel MOSFET

Applications

• Replacing electromechanical relays in automotive power distribution systems
• Replacing fuses in high-current power management circuits
• Discrete device replacement in automotive electronic control units
• High-side switching applications requiring self-protection and diagnostic feedback

Procurement Notes

Verify the specific suffix BHFK against the official NXP datasheet to confirm package type and tape-and-reel specifications. Ensure compatibility with ISO26262 functional safety requirements if used in safety-critical automotive systems. Confirm that the procurement source provides valid traceability documentation consistent with NXP's product longevity program policies.

Selection Notes

Select this component when a single high-side switch with integrated self-protection and diagnostic feedback is required. It is suitable for applications needing PWM control up to 60 kHz and low on-resistance to minimize power loss. Consider the need for external low-side MOSFET control and reverse battery protection when evaluating alternative discrete solutions or relay replacements.

Part Context

The MC33981 series belongs to NXP's portfolio of high-current power switches designed for automotive environments. It replaces traditional electromechanical components like relays and fuses, offering enhanced reliability and diagnostic capabilities. The device is part of a family that includes variants with different suffixes, all sharing core high-side switching functionality with integrated protection features.

Replacement Considerations

MC33981ABHFK and MC33981ADHFK are listed as similar parts with identical functional descriptions and specifications.