Hi Sirs,
As a following of the thread of https://e2e.ti.com/support/audio/f/6/t/691775 ,we found a workaround to reduce pop noise when changing output volume by I2C. Here are our test setup and result:
1. Write TPA6130 I2C by TotalPhase Aardvark I2C dongle:
2. Measure pop noise by Audio Precision equipment and digital scope.
Power Up Sequence:
+5V ON
Write 0x01 = 0xC0
Write 0x02 to setup output volume
Write 0x01 = 0x00
+5V OFF
Test Result:
The pop noise from the TPA6130 itself is lower then -70dBV when applying power supply and writing output volume register. Here is the measurement result:
However, we can tell significant sound glitch of discontinuous signal when changing output volume. Here is the example when updating 0x02=0x25 to 0x02=0x35:
Thesound glitch can be minimized by changing output volume gradually. For example if we want to change 0x02 from 0x25 to 0x2A, we can write 0x02 = 0x26, 0x02=0x27, 0x02=0x28, 0x02=0x29, 0x02=0x2A for five steps. The signal level changes smoothly in this condition.
Thank you and Best regards,
Wayne Chen
01/07/2020
