LM4670: Output noise without input

Hi Jason,

Welcome to E2E, thanks for your interest in our products.
What kind of noise is the device getting? Is It getting pop noise or click noise?
You could have a look at the following devices: TPA2010D1 and TPA2011D1. They are audio amplifiers newer than LM4670.

Best Regards
José Luis Figueroa
Applications Engineer

Hi Jose,

The noise is kind of white noise as long as the SHUTDOWN pin is high even without any input signals. This issue can be found in my 2 different layout projects so I think it might be SPK AMP issue.

I use LM4670 with WSON package. Is there any newer chip pin to pin compatible with LM4670 WSON package? Since TPA2010/2011 are only with BGA package.  Also, the speaker I use is 4ohm/3W.

Thanks

Jason,

Unfortunately, WSON package is not used in our newer audio devices.
Could you provide me a schematic and layout?

Best Regards
José Luis Figueroa
Applications Engineer

Hi Jose,

I attached my layout and schematic of the LM4670 portion. Please help check it out.

Is the output noise a known issue? 

Thanks

SCHEMATIC1 _ 04-MB_SPK.pdf

Jason,

The schematic and layout seem to be correct. Could you provide me graphs of the device output pins and shutdown pin when the problem is going on?

Best Regards
José Luis Figueroa
Applications Engineer