SLOSE75B February 2022 – March 2023 TAS2780
PRODUCTION DATA
The TAS2780 can check the speaker terminal for open or short. This can be used to verify the continuity of the speaker or the traces to the speaker. The entire operation is performed by the TAS2780 and result is reported using the IRQZ pin or by reading over I2C bus on completion. The load diagnostics can be performed using external audio clock (register bit LDG_CLK=0) or the internal oscillator (LDG_CLK=1).
The speaker open (upper - UT) and short (lower - LT) thresholds are configured using the LDG_RES_UT[31:0] and LDG_RES_LT[31:0] register bits. The diagnostic is run by selecting one of the load diagnostic modes set by MODE[2:0] register bits. The load diagnostic can be run before transitioning to active mode or stand-alone returning to software shutdown when complete. When the load diagnostics is run it will play a 22 kHz at -35 dBFS for 100 ms and measure the resistance of the speaker trace. The result is averaged over the time specified by the LDG_AVG[1:0] register bits. The measured speaker impedance can be read from LDS_RES_VAL[31:0] register bits.