Mercury battery overconsumption caused by the PCA9539PW chip

[xinapak]

To Whom This May Concern,

I installed and tested your PCA9539W (Interface-I/O Expander) chip on our devices in batch and shipped them to our end users after confirming their quality. Several months later, some of our end users told us they found 0.9% of chip defect in more than DC:1731 of the chip’s production batches, which led to the overconsumption of button mercury cells. To be specific, when the button mercury cells are used in a power-off state, the IC can continue to function provided that the power supply is given some time. If battery over-discharge occurs, the battery will only last for months at most, even if the design service life is 2 years.

The attached file is my detection and analysis method for the defective products

May I ask whether the attached detection and analysis method can prove the quality problem of PCA9539PW chip?

Or is the chip damaged due to improper use by the client?

Is there a way to verify this type of problem?

Please give your valuable comments and Suggestions

Thank You!

[reyes]

Hi,

According to your description, if the issue is corrected when you solder a good PCA9539W in a failing board, then we can conclude that this could be seen as an issue with the device, however, it would be hard to know if it was caused by a quality issues with the device or an improper use by the client without doing a CQC failure analysis to understand the cause of the problem.

I recommend you to send failing samples to the NXP Quality team for a failure analysis, to do this, please contact your NXP authorized distributor directly and ask them to initialize a CQC (failure analysis), they should be able to help you to know who to contact within NXP to start with this process.

This is done directly through the distributors and cannot be done directly with NXP.

Regards,

Jose

[xinapak]

Hello,

• The problem is that I bought the PCA9539PW chip from a spot vendor，spot vendors do not provide any after-sales service.

• Is there any other way to send it to the authorized dealer of NXP Company or other relevant departments for CQC testing?

• Ask for valuable guidance!

• Thank You!

        Regards,

        Xinapak

[reyes]

Hi Xinapak,

The problem is that if the parts were not acquired from one of our authorized distributors or directly from NXP, we cannot assure you are not using counterfeit parts, reason of why our quality engineers in charge of the CQC failure analysis cannot accept devices from other vendors other then the authorized.

Sorry for the inconvenience.

Regards,

Jose