TDA7381

Overview

The TDA7381 is a Class-AB audio power amplifier in a Flexiwatt-25 package designed for automotive applications. It features four channels with a maximum output of 4 x 30 W into 4 Ω. The device operates on a single supply voltage ranging from 18 V to 28 V, with a typical quiescent current of 300 mA at 14.4 V. It delivers low distortion (0.04% THD+N) and includes an internally fixed gain of 26 dB. The amplifier supports rail-to-rail output swing without bootstrap capacitors.

Feature Summary

• Fully complementary PNP/NPN output configuration enables rail-to-rail output voltage swing without requiring external bootstrap capacitors.
• Integrated clipping detector simplifies gain compression operations within the audio signal path.
• Comprehensive fault diagnostics detect assembly errors including output shorts to ground or supply, thermal shutdown, and clipping events.
• Extremely reduced external component count due to internally fixed gain and absence of external compensation requirements.

Applications

• Car radio audio amplification
• Automotive speaker systems
• High-end car radio equipment

Procurement Notes

Verify the specific suffix variant against the manufacturer datasheet to ensure compatibility with the intended PCB footprint and pinout configuration. Confirm that the Flexiwatt-25 vertical package matches the thermal management design requirements for the target enclosure. Ensure the single-supply voltage range aligns with the vehicle's electrical system specifications before integration.

Selection Notes

Select this component for designs requiring high channel density in a compact form factor. The internal fixed gain eliminates the need for external feedback networks, reducing bill of materials complexity. The robust protection suite makes it suitable for harsh automotive environments where load dump and short-circuit conditions are prevalent.

Part Context

This device belongs to STMicroelectronics' portfolio of automotive Class-AB audio power amplifiers. It is engineered specifically for the demanding electrical and thermal conditions found in vehicle interiors. The Flexiwatt-25 package provides efficient heat dissipation for high-power operation while maintaining a small physical profile suitable for modern dashboard installations.

Replacement Considerations

Check for direct pin-compatible upgrades within the same product family if higher power output is required. Verify that any substitute maintains the same Flexiwatt-25 package dimensions and thermal characteristics to ensure mechanical fit without redesigning the heatsink structure.