SLAAEV1 July   2026 TAS6424E-Q1

 

  1.   1
  2.   Abstract
  3. 1Principles of AC Diagnostics
    1. 1.1 What is AC Diagnostics
    2. 1.2 Implementation Principle of AC Diagnostics
  4. 2AC Diagnostic Flow
    1. 2.1 Review of the AC Diagnostic Flow
    2. 2.2 AC Diagnostics Reference Code
  5. 3Common Issues and Debugging Strategies in AC Diagnostics
    1. 3.1 Inaccuracy in AC Diagnostics Caused by Excitation Signals
    2. 3.2 Measurement Errors Caused by Unstable Connectors
    3. 3.3 TAS6424E-Q1 Status Register Abnormality
    4. 3.4 TAS6424E-Q1 AC Diagnostic Debugging Flow
  6. 4Conclusion
  7. 5References

2.1 Review of the AC Diagnostic Flow

The AC diagnostic workflow is divided into four key stages: first is the pre-preparation, ensuring all channels are in the Hi-Z state and inputting a 19kHz, 0-dBFS sine wave; next is the phase reference calibration, which measures the inherent system error by enabling the internal loopback (0x16 Bit 7); then comes the actual load measurement, where the loopback must be disabled to connect the external loudspeaker, and the chip performs a 32/64-point sampling of the output current (plugging or unplugging the load at this moment will directly cause fluctuations in the sampled current and a spike in the impedance value); finally, during the data reading and calculation stage, the raw data for phase, excitation strength, and impedance are retrieved from the I2C registers and applied to the datasheet formulas to complete the analysis before exiting the diagnostic mode.

Impedance Formula (Impedance):

Equation 1. I m p e d a n c e C H x o h m = I M P C H x * 2.37 m V G a i n * I d a c m A

Phase Formula (Phase):

Equation 2. P h a s e C H x d e g r e e = 360 * P H A S E C H x L B K - P H A S E C H x L D M S T I C H x L D M