Can’t write to MP2888A

DC-DC Power Converters
1

I’m working on nVidia V100 which operates on 2 MP2888A for FBVDD and NVVDD I’m able to read all parameters from them without any issue but as soon as I’m trying to write to their registers (e.g. reg 0x21h vout_command) it doesn’t accept any changes and this is true for all of them.
I noticed that register 0x13h write_protect is set on both to 0 insted of 63h as it should be according to datascheet but I can’t change this reg also.
My question is: any steps must be taken to overwrite register 13h e.g controller must be disabled or any other steps needs to be performed ? or onece reg 13h is set to WP there is no chance to disable it back ?

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Also I noticed in datasheet on page 21 that reg DBh is used to enable eeprom write protection which is probably a mistake as register DBh is described as MFR_SLOPE_CNT_1P which confused me a bit. thaks in adwance

2

HI @areko26 ,

Thank you for reaching out to the MPS Forum! I see you are posting due to the inability to write to the registers. If write protections is not needed, you can set MFR_USER_PWD (04h) to 0x0000. Once the password has been entered/disabled you should be able to access the registers.

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If you require the password, please submit a ticket to MPSNow Remote Support and we can work to get that password to you.
MPS NOW Remote Support - Support