FS6500 VAUX 5V no output

[Lync123]

Hi NXP team,

I have an issue with FS6520 VAUX output that need your help. The hardware schametics are attached.

The select pin-31 is connected a 24 kohm resistor. The DEBUG mode is enabled by connecting Pin-15 DEBUG to a voltage divided from VPRE 6.5V. SW_CORE is confirmed to output around 1.25V.

VCCA and VAUX are both connected to an external PNP transistor (BCP52-16,115). On output of VCCA, an 3.28V output voltage can be measured on Pin-43 VCCA, and it's around 5.9V on VCCA_B and 6.6V on VCCA_E. However, on pin-38 VAUX, it's close to 0V, and it's around 7.8V on VAUX_B and 8.2V on VAUX_E.It looks FS0B is also pulled down LOW.

Currently there's no SPI or software available. It will be appreciated if you can provide any suggestions to debug this issue. Thanks a lot in advance!

Regards,

Lync

[TomasVaverka]

Hi Lync,

There seems to be another thread with the same problem that my colleague Guowei is currently dealing with. Therefore, I will let him continue to do so to not duplicate the effort.

BR, Tomas

[Lync123]

Hi Tomas,

Thanks for your reply. For sake of efficiency, I have just closed another ticket reporting the same issue. It will be great if any of you can continue to provide advise under this post. Thanks.

Regards,

Lync

[TomasVaverka]

Hi Lync,

I do not understand the discussion in Chinese you have had with Guowei on the same topic in another thread. Therefore, please continue to discuss with him, it does not matter if you use your private email there.

BR, Tomas

[Lync123]

Hi Tomas,

Thanks for the feedback.

@guoweisun  As we have exchanged in the first thread, can you spend some time to investigate into this issue and give us some advice? We are really blocked by this problem. If you need further information, please let us know. Thanks.

Regards,

Lync

[guoweisun]

Please show me phone number I will call you back! or send phone number to guowei.sun@nxp.com