SLOA349 March   2025 TAS6584-Q1 , TAS6684-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2SDOUT Configuration
    1. 2.1 SDOUT – I2S Configuration
    2. 2.2 SDOUT – TDM Configuration
  6. 3SDOUT Connection in Multi-Device System
  7. 4Output Current and Voltage Calculation
  8. 5Summary
  9. 6References

1 Introduction

During audio playback, TAS6x84-Q1 internal DSP can calculate output voltage of each channel according to audio input, supply voltage, analog gain, and digital gain setting. This voltage is defined as Vpredict, as this is a scaled signal of output signal level. The speaker impedance is not linear in audio band, so the output current is not fixed even though output voltage is same. The output current sense, Isense, is as scaled value of the actual current. The output current sense is monitored for each channel and reports the measurement to a host processor through SDOUT pin in either I2S mode or TDM mode with minimal delay. Isense and Vpredict can be transmitted on SDOUT pin. The following data groups can be transmitted through SDOUT:

  • Isense Ch1-4 – Scaled Current Sense feedback per channel
  • Vpredict Ch1-4 – Scaled Output voltage estimate based on supply voltage and input signal by channel. Vpredict data is only available at 48kHz sampling frequency and not supported at 96kHz or 192kHz.
  • Aux Ch1-4 - Auxiliary data channels. For more details see the Auxiliary Data Channels section in the data sheet.

Each of the SDOUT pins can transmit only one device’s measurement data. In a multi-device system, the SDOUT pins can be connected together to share one TDM line to save DSP/SOC pins and resources.