Si4735 - Removing the loud click in the speaker during power down and power up.

Подробнее о видео

See:
See:

Some users may be uncomfortable with the loud popping of the speaker during some transitions caused by some Si47XX device commands.
This problem occurs during the receiver transition from the power down to power up. Also, every time the user changes the mode (FM to AM or AM to FM) the power down and power up sequence is required by the Si47XX devices.

The SI47XX device has a 0,7 V DC  (DC bias) component in the analog audio output pins (for example, SI4735-D60 pins 23 and 24 ). When this device enters on  power down mode, the voltage on the audio output pins drops  to 0V. The device do it internally and we have nothing to do to avoid that.
When we power the device up via command, that output audio pins suddenly goes to the  0,7V DC again. This transition causes the loud pop in the speaker.

So far, the author of this library have not found an internal solution to solve the loud popping of the speaker. It is important to say that internal SI47XX mute or volume commands do not work.
However, it is possible to solve this problem by adding an extra mute circuit and control it by the controler (Atmega, ESP32, STM32 etc).
See also:
PU2CLR SI4735 Arduino Library with SSB support -
PU2CLR AKC695X Arduino LIbrary -
PU2CLR KT0915 Arduino LIbrary -
PU2CLR SI4844 ARDUINO LIBRARY -
PU2CLR SI470X Arduino Library with SSB support -


Check SI4732-A10, SI4735-D60 and SI4730-D60