TPS65217: TPS65217 output issue

Mali Kanchan

Part Number: TPS65217

I am using TPS65217C on my board and I have used the Beagle bone black as my reference. I am using Li-Ion battery to power the system and will get charged simultaneously. To increase the efficiency I changed the UVLO to 2.73V and maximum charging limit to 4.2V through I2C interface. I changed the LS2/LDO4 output range to 2.8V.

I have connected a 5V supply to AC pin of the PMIC the voltage across SYS1 & SYS2 pins is 0.15V. When BAT is connected then the voltage across SYS1 & SYS2 pins is 3.77V. But LDO4 output is 0V and capacitor C15 is shorted. Is there a way to bring it back or is it dead? Would replacing TPS65217 fix the problem?

I would really appreciate your help.

Thank you.

over 1 year ago

0 James Steenbock over 1 year ago

TI__Mastermind 20300 points

Hi Mali,

Can you fix the C15 short? That condition doesn't seem ideal. Is LDO4 output shorted to GND?

Can you share a scope capture of the power up sequence starting with:

V_AC, I_AC, VSYS, LDO4
V_AC, nWAKEUP, PWR_EN, LDO4

Please show the startup waveforms for each signal as well as some time after startup to see where the stabilize.

Regards,

James

0 Mali Kanchan over 1 year ago

Prodigy 70 points

Hi James,

Yes Pin number 43 of TPS65217C is shorted to GND i.e. LDO4 output pin

0 Mali Kanchan over 1 year ago in reply to James Steenbock

Prodigy 70 points

I have changed the LDO4 Control Register (DEFLS2) value to 0X35 i .e. LDO4 output will be 2.8V, after doing this change TPS65217C is misbehaving. So is this the reason of misbehaviour?

0 James Steenbock over 1 year ago in reply to Mali Kanchan

TI__Mastermind 20300 points

Hi Mali,

You need to remove the GND short on pin 43. If you want the LDO4 / LS2 output to work properly you cannot have the output shorted to GND.

Let me know if I am misunderstanding this.

Regards,

James

0 Mali Kanchan over 1 year ago in reply to James Steenbock

Prodigy 70 points

Yes GND short should be removed to make the IC work.

But why did the particular pin get shorted to GND. I have not touched other settings of IC.

0 Niko Alatalo over 1 year ago in reply to Mali Kanchan

TI__Genius 17120 points

Hello Mali,

US has a public holiday today February 19th and thus James will get back to you in the next couple of days. Thank you for your patience.

regards,

Niko

0 James Steenbock over 1 year ago in reply to Niko Alatalo

TI__Mastermind 20300 points

Hi Mali ,

The pin shouldn't be shorted to GND if the IC is being used normally with the proper supply inputs. If you have a working board that you can reference I would try an A-B-A swap to see if the issue is the chip itself or the board it's mounted on.

It sounds like you had the IC working properly before the failure occurred. If that's the case then something could have happened to damage the IC since then but I don't know what that could be.

Regards,

James

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TPS65217: TPS65217 output issue