TPS53626: trigger OVP after power on

shihchin lo

Prodigy 50 points

Part Number: TPS53626
Other Parts Discussed in Thread: TPS51623

Tool/software:

Hi, we have issue that can’t power on TPS53626. Fail rate is 8/37units from factory reported.

Finally we found that after we change PC100 from 47nF to 100nF, this issue can be fixed.

Below is VCCRAM output measurement when power on, FYR.

Attached the schematic, please help check what cause this issue and how to prevent it since it has fail rate.

We are afraid that 0.1uF is only the solution to make the fail rate become lower…

Sch, FYR.

./cfs-file/__key/communityserver-discussions-components-files/196/1104.VCCSRAM.pdf

Below is fail & pass waveform:

11 days ago

0 Maha Noor 11 days ago

TI__Intellectual 1560 points

Hi Shihchin,

Csense value can be increased to slow down current sense and prevent false faults. Could you accurately fill out this excel sheet to see what your recommended value of Csense should be?

TPS53625 Calculator DCR Sense_P1V2_2ph_28A_.xls

Also, please send PWM, CSP-CSN, Comp and Droop waveforms. Are you also hitting cycle by cycle OCL when hitting OVP?

Regards,

Maha

0 shihchin lo 11 days ago in reply to Maha Noor

Prodigy 50 points

Hi Maha,

I use calculation file you provide to me but the value is really different from I have before, so I provide the original one I have to you.

I notice that there is TPS51623 mark from yours.

By the way, both 2 files I can't run the marco. So could you provide me the results after running macros? I already filled the data to both execl.

Thanks.

/cfs-file/__key/communityserver-discussions-components-files/196/original_5F00_VCCRAM_5F00_TPS53625-Calculator.xlsm

/cfs-file/__key/communityserver-discussions-components-files/196/E2E_5F00_TPS53625-Calculator-DCR-Sense_5F00_P1V2_5F00_2ph_5F00_28A_5F00_.xls

0 Maha Noor 10 days ago in reply to shihchin lo

TI__Intellectual 1560 points

Hi Shihchin,

I have attached the file after running the macros. The file only highlights that your inductor value is low. Could you please provide the waveforms that I mentioned earlier?

8037.original_VCCRAM_TPS53625 Calculator.xlsm

Regards,

Maha