TPS61090: Not boosting to 5.0V. getting output of 0.6V

Zachery Dunlop

Part Number: TPS61090

Hello

I am trying to obtain an output voltage of 5.0V using the TPS61090. The input voltage at Vbat pin is measured to be 3.8V but the output voltage is measured to be 0.6V.

I believe I have followed the component layout guidelines as proposed in the data sheet.

Could you please suggest possible reasons for this?

Thank you

Power_Schematic copy.brd

over 7 years ago

0 Zachery Dunlop over 7 years ago

Prodigy 230 points

0 Zachery Dunlop over 7 years ago in reply to Zachery Dunlop

Prodigy 230 points

0 Jasper Li over 7 years ago in reply to Zachery Dunlop

TI__Mastermind 46905 points

look at your layout, i'm concerning that the device is damaged right after powering up the device.
you can check the impedance between SW pin and GND pin to verify if the device is damaged.

0 Zachery Dunlop over 7 years ago in reply to Jasper Li

Prodigy 230 points

What would you recommend needs changing in the layout?

Thank you for your help!
-Zach

0 Zachery Dunlop over 7 years ago in reply to Zachery Dunlop

Prodigy 230 points

I've tried to follow the recommendations in this paper: www.ti.com/.../slva773.pdf
but I don't know what is causing this issue.

0 Zachery Dunlop over 7 years ago in reply to Zachery Dunlop

Prodigy 230 points

What should the impedance between the SW pin and the GND pin approximately be?

Thanks

0 Jasper Li over 7 years ago in reply to Zachery Dunlop

TI__Mastermind 46905 points

it should be higher than 1M. it decrease the several hundreds ohm or much lower if the device damaged

0 Zachery Dunlop over 7 years ago in reply to Jasper Li

Prodigy 230 points

Ok we Just measured it and its 20k ohms.

0 Jasper Li over 7 years ago in reply to Zachery Dunlop

TI__Mastermind 46905 points

do you have other boards not power up before? you can check the impedance before/after power up

0 Zachery Dunlop over 7 years ago in reply to Jasper Li

Prodigy 230 points

We do have other PCBs but we would need to solder the components on them. right now we only have the one board with components soldered on.

0 Zachery Dunlop over 7 years ago in reply to Zachery Dunlop

Prodigy 230 points

Could incorrect component placement be the of the damage to the IC?
Thanks

0 Zachery Dunlop over 7 years ago in reply to Zachery Dunlop

Prodigy 230 points

Could incorrect component placement be the cause of the damage to the IC?
Thanks

0 Jasper Li over 7 years ago in reply to Zachery Dunlop

TI__Mastermind 46905 points

yes. the damage of the IC is mostly caused by layout problem

0 Zachery Dunlop over 7 years ago in reply to Jasper Li

Prodigy 230 points

I changed the layout of the components for the TPS61090. Do you have any recommendations on if this layout will have the same issue?

0 Zachery Dunlop over 7 years ago in reply to Zachery Dunlop

Prodigy 230 points

0755.Power_Schematic copy.brd

0 Jasper Li over 7 years ago in reply to Zachery Dunlop

TI__Mastermind 46905 points

it is still not good as the routing of the C2. i will reply your another email thread and closed this one.

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TPS61090: Not boosting to 5.0V. getting output of 0.6V