TPS65252: TPS65252

Darsana Ajay Sree

Part Number: TPS65252

Hi I am using TPS65252 in one of my designs and one of the cards I was debugging and found that Enable 1 & 2 are continuously pulsing and hence the outputs are not coming. Can you please let me know what may be the reason.

V7V & V3V are verified and coming as expected.

Please find the design for your analysis

over 1 year ago

0 Lucia Gao over 1 year ago

TI__Mastermind 21780 points

Hi Darsana,

Thanks for reaching out! Last time we recommended to change Css Capacitors from 10UF to a value no larger than 30nF. And from your feedback, after you changed the Css Capacitors from 10UF to 4.7nF and the Output1(2.5V) & Output2 (1.8V) are coming as expected. Is the output not coming a new issue this time? I believe last time you have solved the Vout not coming issue.

Thanks and kindly let us know anything unclear!

BRs

Lucia

0 Darsana Ajay Sree over 1 year ago in reply to Lucia Gao

Prodigy 40 points

Hi Lucia,

This is a different issue which I am facing in one of the cards as I have mentioned. The Css capacitors are 4.7uF. The Enable lines are pulsing as shown in the scope capture and hence I am not getting the voltage outputs. May i know the reasons for Enable line not high all the time evenif V7V & V3V are good?

0 Lucia Gao over 1 year ago in reply to Darsana Ajay Sree

TI__Mastermind 21780 points

Hi Darsana,

Do you have chance to try to change the Css to no larger than 30nF, for example, 4.7nF? Thanks!

BRs

Lucia

0 Darsana Ajay Sree over 1 year ago in reply to Lucia Gao

Prodigy 40 points

Hi Lucia,

The Css Capacitors where changed to 4.7nF in this particular board also which i am facing issue. Sorry for the typo, value of the Css is 4.7nF and not UF. Please let me what other factors can cause this issue for Enables getting pulled down or pulsing (refer the scope capture). V3V & V7V ,VIN are verified and good.

0 Lucia Gao over 1 year ago in reply to Darsana Ajay Sree

TI__Mastermind 21780 points

Hi Darsana,

What is the difference between this particular board and good board?

Thanks!

BRs

Lucia

0 Darsana Ajay Sree over 1 year ago in reply to Lucia Gao

Prodigy 40 points

There is no difference in this board wrt to good boards in terms of design/components. It will be great if you can let me know what other factors will affect the Enable lines???

0 Lucia Gao over 1 year ago in reply to Darsana Ajay Sree

TI__Mastermind 21780 points

Hi Darsana,

EN pin voltage should not be continuously pulsing with normal operation. Could you please capture the waveform of VIN and V3V together with EN in one waveform? Please first remove C156 and C1868 and capture EN waveform? Then, please change C156 and C186 with new 4.7nF and try again?

Thanks!

BRs

Lucia

Power management

Power management forum

TPS65252: TPS65252