VR5510 can not go to standby mode

[LIU_HAO]

Hi,
I want to run the standby demo provided by Johnli on the s32g274a device we designed ourselves, but I am facing the following problems.

When I powered on the device , the device ran the code correctly(send uart message and send i2c commands to 5510 correctly ), then a reset occurred, and the code ran again incorrectly (send message correctly but send i2c commands incorrectly ) and then vr 5510 worked normally.

Here are i2c waves , at the second part of waves, i2c commands read FS_STATUS repeatedly and the result was 0008.

The PMIC_STBY pin and STBY_PGOOD pin were pulled down temporality.

The wave of reset pin was strange

The voltage of the VPRE should be 3.0V when go to standby mode . In our device,it was pulled up 3.3V

Our design almost references S32G-VNP-RDB2. Considering the design cost, we cancelled the other 3.3Vpmic in addition to the 5510. 

Please tell me ,what are the reasons for this phenomenon. Whether the above phenomenon is related to insufficient power. How can I solve this problem.

Thank you very much

S32G-VNP-RDB2 

[Daniel-Aguirre]

Hi,

We might be misunderstanding the overall inquiry. If so, we do apologize.

We understand that you are working with custom hardware, is this correct? Are you able to run this same example under NXP hardware? Is the behavior the same?

From our side, we are able to run the example and don't seem to be able to replicate the behavior you are describing. Are you flashing the image? Or are you using a debugger?

Please, let us know.

[LIU_HAO]

Hi,

I've flashed standby_blob.bin into both custom hardware and NXP hardware.

The program runs correctly in S32G-VNP-RDB2. After sending i2c commands to 5510, 5510 went to standby mode. The voltage of RESET pin and VPRE dropped from 3.3V to 3.0V(set in the code). 

The same program runs incorrectiy in custom hardware.  After sending i2c commands to 5510, 5510 attempted to go to standby mode. The STBY_PCOOG was pulled down. But the voltage of RESET pin dropped from 3.3V to less than 1v, then there was a reset. The program ran again, but the i2c commands were wrong, The MCU read FS_STATUS repeatedly for about 10s.

I think the key of the problem is the reset singal caused by the incorrect voltage dropping.

The voltage dropping may caused by our hardware design.

Is there any internal mechanism of 5510 or MCU that could cause this reset?

[Daniel-Aguirre]

Hi,

Thanks for your feedback. For what we are able to understand, given that under the NXP hardware the behavior cannot be replicated, this does seem to be related to the custom hardware.

On regards of the specific situation under the MPU, we understand that given it was set to sleep, not all systems are turned-on. For those turned-on, we don't seem to see anyone related to lowering the RST pin under a STBY state. 

Under this community we mainly support S32G products, for VR5510 specific features we can recommend either opening a ticket under the NXP online services or contacting your local NXP FAE/DFAE/representative. We do apologize.

Please, let us know.