TPA3111D1: Popping sound during test

Hi Ryotaro,

The pop is mainly from mismatch of input when start-up. 

Could you tell me the input capacitors value and size?

You can ask customer to change smaller value and big size capacitor.

Regards,

Derek

Hi Derek,

Thank you for your response.

The customer understood that the main cause of the popping sound is a mismatch in the input that occurs at startup. Based on that, I receive following feedbacks from them:

[Current Input Capacitors]

The capacitor capacity is 1uF, as same as the IC data sheet and TPA3111D1EVM data sheet.

For detail information on capacitors connected to INP and INN terminals, please refer to the following.

• Model number: GRM155R61E105KE11D

www.murata.com/.../productdetail

• Capacity: 1uF
• Size: 1.0 mm x 0.5 mm
• Rated voltage: 25V

Note: The TPA3111D1 has a power supply of +24VDC.

The INN terminal is connected to GND via the above capacitor.

The INP terminal is also connected to the LM1971 (DC+5V supply) via the above capacitors.

Could you teach us why it improves by changing to a smaller, larger capacitor? We are not familiar to it.

Regards,

Ryotaro Fukui

Hi ,

Derek is on a business trip, we will reach you back soon.

BR 

Hi Derek,

I have received a comment from the customer that the customer's pop noise was successfully resolved by changing the capacitor to smaller value. Thank you for your help.

Regards,

Ryotaro Fukui