Dear, TI Community.
According to http://www.ti.com/lit/pdf/swru281 on the schematic (page 19) there is "jumper" R15. R15 can connect FPWM with GND or with VBUS. Note that VBUS = 5V. (By default FPWM is connected to GND.) And VOUT (from BQ25015) is 2.15V.
According to http://www.ti.com/lit/gpn/bq25015 page 2: Max Input voltage FPWM=(VOUT + 0.3 V).
It is a bit strange, that in the swru281 schematic jumper R15 can be connected to VBUS=5V. In this case input voltage FPWM will be exceed max allowable voltage by 2.85V.
We removed R15 from CC85XXDK-HEADSET and we connect VBUS with FPWM by 2.2K resistor. In this configuration robustness is much better than with default configuration (with R15 jumper on GND). We did this changes for Master device.
It should be noticed that our master sends 3 channels PCM16 data and slave receives all this 3 channels. And only in this case we have very bad robustness. With Preloaded Demo or other 2-channels PPW Configurator examples there is no problems with robustness.
Could you comment situation about mismatching http://www.ti.com/lit/gpn/bq25015 and http://www.ti.com/lit/pdf/swru281? And what should better to use for pull-up FPWM to high level?
What will happen if FPWM will be connected to VBUS on Slave device with battery powering?( In this situation VBUS will not be connected to USB.)
Sincerely, Igor
