SLOA349 March 2025 TAS6584-Q1 , TAS6684-Q1
TI’s digital input automotive Class-D audio amplifier, TAS6x84-Q1, supports the measurement of output current and voltage of each channel independently. The TAS6x84-Q1 transmits selected data through the serial audio output port, SDOUT, in either I2S mode or TDM mode. This application note provides an application guide of the measurement of output current and voltage predict.
All trademarks are the property of their respective owners.
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:
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.