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Audio Amplifier

TFA9873: 8 V Highly Power-Efficient Class-D Audio Amplifier


The TFA9873 is a high-efficiency boosted class-D audio amplifier solution associated with speaker protection and boost algorithm. It can deliver up to 4.5 W average output power into a 6 Ω speaker, at a supply voltage of 4.0 V. The internal adaptive DC-to-DC converter raises the supply voltage, providing ample headroom for major improvements in sound quality.


  • High output power:

    1. 4.5 W (average) into 6 Ω at 4.0 V supply voltage (THD = 1 %)
    2. 3.5 W (average) into 8 Ω at 4.0 V supply voltage (THD = 1 %)
  • Supports handset (16 Ω or 32 Ω) and hands-free (4 Ω to 8 Ω) speaker configurations

  • High efficiency, low power dissipation, and low-noise speaker driver

  • Adaptive DC-to-DC converter increases the supply voltage smoothly while switching between fixed boost and adaptive boost modes. It thus, prevents large battery supply spikes and limits the quiescent power consumption

  • Wide supply voltage range (fully operational from 2.7 V to 5.5 V)

  • Very low-noise output voltage, 9 μV

  • Low battery current consumption, 120 mA (Po = 380 mW, average music power)

  • I2C-bus control interface (400 kHz)

  • Speaker current and voltage monitoring (through the TDM-bus) for acoustic echo cancellation (AEC) at the host

  • 16 kHz/32 kHz/44.1 kHz/48 kHz sample frequencies supported

  • Ultrasonic support via TDM running at 96 kHz

  • Programmable interrupt control via a dedicated interrupt pin

  • Low RF susceptibility

  • Thermal foldback and excessive temperature protection

System Block Diagram

Application Block Diagram


  • TFA9873 SDS

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