Hi Sir
We would like to use PWM_CTRL function to control external boost on EVB. After we initialized TAS2781EVM and typed in below command.
w 70 00 00 #Page 0x00
w 70 7A 20 #PWR CTRL
w 70 00 00 #Page 0x00
w 70 6A 05 #LVS_RTH
Then adjusted input from 0dB to -40dB.
But we didn't see the signal with a duty cycle on the PWM_CTRL pin as written in the datasheet.
Even though we remove R6 pull high 1K register.
Could you help to figure out the operation method?
-----------------------------------------------------------datasheet below-------------------------------------------------------------------------------------------
When enabled, the controller generates at PWM_CTRL pin a signal with a duty cycle proportional to the peak voltage on the speaker. Using an external RC filter the signal is converted to an analog voltage and can be used to control boost converters with feedback input.
The figure below shows how the PWM_CTRL pin can be connected to the external boost control RC network.