TPS65219: TPS6521903RHBR No power output

Hi,

Thanks for reaching out. Could you provide more information on the differences between "market purchased board" vs "newly designed board"?

Additionally, could you provide the PMIC schematic in a searchable PDF so we can perform a review?

Thanks,

Brenda

Market purchased board is the BeaglePlay (https://www.beagleboard.org/boards/beagleplay) and Newly designed board is the same board I designed with the schematic available (https://git.beagleboard.org/beagleplay/beagleplay).

Attaching the PDF format for the PMICPlay-SoC GPIO 3.3V.pdfPlay-DC_DC AND PMIC.pdf

Thanks for sharing the schematic! The internal parameters for the buck converters are optimized for 0.47uH inductor. Could you change the inductor on Buck1 from 0.33uH to 0.47uH?

After the Buck1 inductor is changed. Could you also share a scope capture with the following signals:

• VSYS
• BUCK2
• LDO3
• BUCK3

Thanks,

Brenda

I had changed the 0.33uH inductor with the 0.47uH inductor and below is the outputs of the PMIC.

Pink represents VSYS

Blue Represents Buck3(Pin 27)

Green represents BUCK2(Pin 29) 

Yellow represents LDO3(Pin 21)

Additionally will be sending you one more waveform 

Pink represents VSYS

Green represents Enable

Yellow represents TLV62595 Buck convertor (pin 5 output)

Blue Represents GPO2

Hi,

The last scope capture shows significant noise coming from the external TLV62595 Buck. Could you disconnect the load from all PMIC rails and isolate the power solution?

Thanks,

Brenda

Hello,

I tested  with the no load condition the results are same.

Additionally I had also testing the sequence again, 

Pink represents VSYS

Blue represents Enable

Yellow represents GPO2

Green Represents buck 2 output after inductor.

If the green channel is Buck2, does that mean you are getting 5V on Buck2 when it tries to turn ON?

Thanks,

Brenda

sorry, GPO2 is green and buck 2 output is yellow. Please let me know the root cause 

thanks

Mohit

Do I have to configure it first from the TPS65219 GUI from TPS65219EVM-SKT to turn on the Buck outputs.

 I have also tested the same TPS6521903RHBR IC to solder directly to beagleplay board and it shows me the output of every buck and LDO's outputs as mentioned. So from this I think that it doesn't need preprogramming for using.

thanks 

Mohit

Hi,

TPS6521903 comes pre-programmed from factory so it doesn't require NVM programming. 

From the scope captures we have received so far, it seems like GPO2 as well as Buck2 are turning-ON for a period of time. Could you provide a similar power-up scope capture for the remaining PMIC rails to see if they turn-ON for a period of time?

Do you know why the external 3.3V Buck (TLV62595) has so much noise at the output? I'm suspecting this could be affecting LDO1, LDO3 and LDO4 because these LDOs are supplied by the external Buck. 

Thanks,

Brenda

I have supplied 3.3V from external souce not from TLV62595. For the above testing. 

Thanks

Mohit

Hi,

I am also getting a voltage of 1.8V at VDD1P8.

Additionally. I feel like there could be some error in the Schematic. Please review the schematic and please let me know the minimum circuitry to run the Buck2 output (1.8V) and then remaining buck and LDO outputs

Thanks

Mohit

Hi Mohit,

What is the sequencing of the external supply that was used to supply the LDOs? Does it turn-ON at the exact same time as VSYS? Could you provide a scope captures of VSYS, the external supply of the LDOs and all the PMIC output voltages (Bucks and LDOs)?

Thanks,

Brenda

Below are the waveforms listed as follows -

Green - PVINLDO1

Blue - PVINLDO2

Yellow - PVINLDO34

Green - VLDO1

Blue - VLDO2

Yellow - VLDO4

Green - VDD1P8

Blue - VLDO3

Yellow - 3.3V out from TLV62595

Green - PVIN_B2

Blue - PVIN_B3

Yellow -PVIN_B1

Green - LX_B2 after inductor

Blue - LX_B3 after inductor

Yellow - LX_B1 after inductor

Green - EN

Blue - Mode/Reset

Yellow - GPO2

Hi Mohit,

Could you provide a picture of the PMIC IC top marking? I'm staring to think you don't have the correct orderable or the channel labels were not identified correctly because I dont see the correct output voltages, sequence and one of the PMIC rails (GPO2) seem to be excluded from the power-up attempts. Here are a few observations:

Mohit Sharma said:

Green - VLDO1

Blue - VLDO2

Yellow - VLDO4

• When LDO1 turns-ON, it only outputs around 1.6V-1.8V but the output voltage of this rail is controlled by the VSEL digital pin. If VSEL is high, LDO1 should output 3.3V.
• Similarly, LDO2 does not have the correct output voltage. TPS6521903 has LDO2 configured to output 0.85V but your scope capture is showing approximately 2.4V. What do you have on channel 4?
• LDO1 and LDO2 are turning-ON at the same time in your scope capture but the TPS6521903 was configured to turn-ON LDO2 6ms after LDO1.

Mohit Sharma said:

Green - EN

Blue - Mode/Reset

Yellow - GPO2

• In this capture, I dont see GPO2 going low and high. The PMIC was design to execute a cold reset if an issue is detected in any of the PMIC rails. Your scope captures show some of the PMIC rails like Buck2, LDO1, LDO2 going low and high (3 attempts) but GPO2 seem to always stay ON. PMIC does not do this.

Did you copy the same exact schematic and layout from the BeaglePlay board? Any schematic or layout differences? Have you try re-placing the PMIC with a new one and also trying on a new PCB? Are you able to completely isolate the PMIC by desoldering any load or external ICs connected to the outputs?

Thanks,

Brenda

Hi Brenda,

 I will be sharing the photo of the IC that was soldered and also I have made several iterations with no load condition, and the output waveforms remain same. I forgot to tell you the Output of GPO2 is remains high because I was directly pull up the pin by 0ohm resistance instead of 10K as mentioned. Refer to the schematic Resistor R2.

After now I again put it 10K resistance on R2 and then I am getting the below waveform.

Green represents GPO2

yellow represents output of TLV62595.

After connecting 10K in place of 0R (R2) the output of BUCK U2 is also not turning ON because the GPO2 is directly connected to the enable pin of TLV62595.

I had copied the Exact same schematic . For layout considerations I have followed the Datasheet of the PMIC not the beagleplay board layout.

I had also tested by placing my ordered PMIC on the beagleplay and beagleplay PMIC on my board. But it doesn't work. The beagleplay works fine but having the same issue with our board.

By the way I figured it out that the beagleplay preinstalled IC is PTPS652193 is it same as TPS6521903RHBR.But as mentioned in the Schematic and documentation they have used TPS6521903RHBR as mentioned in their BOM.

Yes I had made 2 board with the exact no load conditions, with only PMIC and TLV62595 BUCK.

Please let me know if their are differences in PTPS652193 and TPS6521903RHBR

Hi,

Brenda

Please update on this.

thanks 

Mohit

Hi Mohit,

"TPS652193" is not an active device in our portfolio. BeaglePlay uses TPS6521903. I'm wondering if there were any differences in your schematic compared to the Beagle board. It seemed very similar but it wasn't an exact copy because at least the Buck1 inductor was different.   

Have you done a detail visual inspection of the soldering in your PCB? From the picture that was shared we can identify multiple areas of improvements from solder joints that are not clean.. The Buck1 inductor seem pretty big in size and the output caps from all Bucks do not seem to be installed. The 2 boards you mentioned in your previous message, do they only have PMIC and external Buck? no other ICs/load at all (including the VTT rail for the DDR)?

Could you share the PMIC layout in a .brd file or Altium file?

Thanks,

Brenda

Hi

Brenda,

I have done the detail visual inspection of the board. I think so not installing the output caps will result in shut down of PMIC. The 2 boards I have said have PMIC and the 3.3V buck convertor. I have designed this project in KiCAD software as its not the Altium file so I will be sharing you the Gerber of that whole board. 

Additionally I think that there are some issues the layout as FBx pins are connecting to the zones instead of connecting with the traces. I had tested with connecting the PMIC outputs of beagleplay of all Buck and LDO's to my board with every load connected and PMIC unsoldered on my board. Encountered the same issue with after some ms the 3.3V shuts down. Then I unsoldered all the wires and test it with only attached the 3.3V and then when I was connecting the 1.8V buck the PMIC shuts down.

I will also be attaching the whole project folder

Play.zip

GERBER_BEAGLEPLAY.zip

Thanks 

Mohit

hi Brenda, 

Can I know the dependency for turning On the GPO2 and 1V8(Buck2) voltage according to the schematic what are the important components that need to be soldered. 

Need minimum number of circuitry and will do the testing in phases.

Thanks Mohit

Hi Mohit,

To test the minimum circuitry for the PMIC, you just need to completely disconnect the PMIC load from all Bucks and LDOs. For Bucks, you just need to keep the input/output caps and inductor.

Thanks,

Brenda

Hi Brenda, Can I know the dependency for the GPO2 pin which tries 3 times to pull up, ACC to power sequence first GPO2 will be ONN the remaining Bucks and LDO will be ONN.

thanks 

Mohit

Hi Mohit,

Mohit Sharma said:

Can I know the dependency for the GPO2 pin

Could yo clarify this question? What do yo mean by "dependency"? GPO2 is configured to be part of the power-up/power-down sequence. If the device detects a fault in any of its rails, it executes a COLD reset on all DCDCs, LDOs and GPOs. 

Thanks,

Brenda

Hi Brenda,

Please let me know if there are issues related to layouting.

Thanks and regards 

Mohit