TLV320ADC3101: schematic review

user4656546

Part Number: TLV320ADC3101

Hi TI team:

We have a MP project which used TLV320ADC3101, during the FCT test, we found some abnornal frequency output when there is no input, we just inser an AUX cable from PC.

Pls help to check if the power supply and input part is OK in the schematic?

TLV320ADC3101 circuit.pdf

over 5 years ago

0 Diego Melendez over 5 years ago

TI__Guru 57800 points

Hi,

I reviewed your schematics and everything seems to be in order. The power supplies connection is correct and the pseudo-differential input seems fine. Can you provide more information about the abnormal frequency?.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 user4656546 over 5 years ago in reply to Diego Melendez

Intellectual 475 points

Dear Diego:

Customer said it's mass production test. they connect a aux cable(from PC) to this ADC, and the digital out connect to PC, then the test result will show '50HZ', it's the result they want. but some PCB will show 1500HZ~5000HZ, they think it's has problem, they did ABA test and confirm the ADC is 'abnormal', request for FA.
Customer said there is not input signal at all, and when they short the input to GND, the test result will betwen 1500HZ to 5000HZ on both good and defected PCB.

Do you have any suggestions to end this issue?
CQE thought it's application issue.

Pls advise if the test in customer side is wrong.

Thanks.

0 Diego Melendez over 5 years ago in reply to user4656546

TI__Guru 57800 points

Hi,

Thanks for the feedback. From my point of view, the schematic is correct, but what I can't see is the input stage, can you please share it?. Is the issue present in a single unit?

Regarding customer test, are they shorting the input pins to GND?, if so, it is not recommended as the input pins have a common mode voltage, the correct way to test is to connect the input before the decoupling cap to GND (similar to grounding Aux cable). Do you know if customer has looked at the ADC performance with a different I²S receiver?.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 user4656546 over 5 years ago in reply to Diego Melendez

Intellectual 475 points

Boston MCU circuit.pdf

0 user4656546 over 5 years ago in reply to Diego Melendez

Intellectual 475 points

Dear Diego:

attached schematic for your reference, I2S output connect to a MCU.

0 Diego Melendez over 5 years ago in reply to user4656546

TI__Guru 57800 points

Hi,

Thanks for the schematic. I was referring more to the analog input stage so we can verify everything is in order with the connection from the source to the ADC inputs. From the latest schematic, it seems it is possible to isolate the ADC from the processor and connect the ADC3101 to a different I²S bus, which would be useful to make sure the issue is not related to the processor. Can you try this?

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 user4656546 over 5 years ago in reply to Diego Melendez

Intellectual 475 points

Dear Diego:

Actually, customer is not sure if the configuration is correct. Pls help to check it.
Honortone had been used this P/N for a long time, they found it had pop noise and sent for FA in 2016, and the result shows that this IC had short failure. so they add the test to screen this kind of failure.

but they can't confirm if the configuration of this test is completely right.