TPS65988: I am working on a TPS65988EVM with TPS65988DH, but I never got any output larger than 5V.

Hello,

Luca L said:

When I plug in Port A, the Port B only output 5V 0.9A for iPad

Do you know what the iPad is requesting?  The source will advertise capabilities but the sink will request which PDO is used.

Luca L said:

I thought the PDO_1, and PDO_0 should be light up to indicate the PD voltage level?

Yes.  Since D3, D5, and D29 are illuminated it would appear that a 5V potential is available/selected.  Please confirm there is no issue with the P3V3 regulator.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1236363/tps65988dkevm-high-quality-schematics-wanted-for-evm---power-supply-section-of-tps65988-evaluation-module-users-guide-is-not-readable/4673822#4673822

Luca L said:

Is that any potential that the board might have failure or is my configuration have some mistake.

I would change the configuration to match DRP (internal paths are source only and external paths are sink only):

Luca L said:

Here is also my log

Can you capture the PD traffic to show what capabilities are advertised and requested?

Thanks and Regards,

Chris

TPS65988 EVM User's Guide

Hello, Chris,

Thanks for your reply.

After I change the PP1, PP2, PP3, PP4 switch config with your advice, either port can support sink on first port and source on the second port. This was a great news to me!

When I plug in Port A as 15V input, the Port B will output as 5V, 0.9A
I can see-
PP2switch: PP2 switch enabled (system output)
PP3switch: PP3 switch enabled (system input)

When I plug in Port B as 15V input, the Port A will output as 5V, 0.9A
I can see-
PP1switch: PP1 switch enabled (system output)
PP4switch: PP4 switch enabled (system input)

Meanwhile, it still only output 5V 0.9A on PD negotiation.

I try move to 12 V capability in this project. project6.pjt

When I plug in 12 V source for either Port A or Port B, there is no output available.
If I plug in Port A, it show PP3 switch enabled (system input), the D3 didn't light up and not output.
 
If I plug in Port B, it show PP4 switch enabled (system input), the D5 didn't light up and not output.

And last, here is the 3V3 on either 15V and 12V. 3V3 is stable but I didn't see any light on PDO_0 or PDO_1 on any port.

Any other things I could do to evaluate the board work properly before any further step?

I try to do "Re-Flash EVM firmware (Recovery)", and I got error message.

Thanks very much.

More observation with the board.

If I connect the board with system power 20V, I can get both port seem to have some PD source configuration output.

But the strange things is that once I try to plug in a iPad, the power meter will show 5V for around 4 seconds, and the PDO_0, PDO_1, IMXCTL0 flash for less than 0.5s, D3 will turn brighter, and next moment, the IMXCTL2, D27 light fade out.

Hi, Chris,

So what is the recommend setup if no battery will be attach to the chips?

I should switch on to the pin 4, right?

Thanks for your advice, it is getting better again, I turn the pin 4 switch on can see different voltage output now by providing the power from a external power supply with 20V.

I can output 9V, 2A afterward. And I see the PDO_0 LED light up for the first time.

This is the project file now, project8.pjt

When I try to setup 12V, 15V. The light will flash once, and turn off immediately, what could lead to this happen?

Also, why 5V is still presence when the 15V PD as input but no any output when 12V PD is plug-in? What else I am missing or mis-config.
 

Hello,

Luca L said:

So what is the recommend setup if no battery will be attach to the chips?

I will need to look into this further to see if this is recommended.  You would need to use a microcontroller or some other means to write to the PD controller to clear the dead battery flag when a valid sink is connected.  This would allow the PD to load from the EEPROM and proceed to the APP mode.  In a typical application the embedded controller monitors the battery and then applies VIN3V3 to the PD controller followed by a command to the PD to clear the dead battery flag.  The PD is then powered from VIN3V3 instead of VBUS.

Luca L said:

I should switch on to the pin 4, right?

This is only applicable when the VBUS is applied before VIN3V3 (barrel jack of evm).  The switch should not impact performance when VIN3V3 is first available.

Luca L said:

When I try to setup 12V, 15V. The light will flash once, and turn off immediately, what could lead to this happen?

For Port1 i only see two source PDOs, 5V and 9V.  Please confirm that the port being tested supports 12 and 15V.

Luca L said:

Also, why 5V is still presence when the 15V PD as input but no any output when 12V PD is plug-in? What else I am missing or mis-config.

This is a little strange.  The sink capabilities for Port 1 are 5, 9 , and 12.  But as you show it supports 15 and not 12.   I have never seen a fixed pdo other than 5, 9, 15, and 20V for SPR.  Do you require 12V?

Regards,

Chris

Thanks very much. With an external 3V3, I can get rid of dead battery flag and see various output option. I think I should be able to ignore the dead battery flag, but I can't see an option in Global System Configuration. How can I change this status?

Meanwhile, is that possible that the power can jump to 9V but not able to 12V or 15V.
I am quite doubt that the board have some issue on 12V or 15V output.

Hello,

Luca L said:

I think I should be able to ignore the dead battery flag, but I can't see an option in Global System Configuration. How can I change this status?

The dead battery flag feature cannot be disabled.  You must use a 4CC command to clear the dead battery flag. Through the GUI you could enter debug mode and send the command.

Can you confirm on your evm that the configuration is being loaded from the eeprom after VBUS is applied?  I would have expected that once the sink port is connected and receiving power then the PD would load the configuration from eeprom and support the 12 or 15 sourcing on the other port.

Luca L said:

Meanwhile, is that possible that the power can jump to 9V but not able to 12V or 15V.

No.  The PD should first provide 5V and then negotiate to the highest possible voltage.  i am not sure why the PD would not go to the 12V or 15V if advertised unless the far end did not select.  

Regards,

Chris

Hi, Chris,

So, I would like to ask is there anyway I can power up the 15V device from the VBUS and output 15V PD at the secondary port when boost up with a 15V PD input?

Because I didn't have a battery for the chip which it will always set the dead battery flag to be true.

I set the Dead Battery Flag to be false after the chip boost up by the debugger, but the one connecting on the second port is still only on 5V, 0.9A. It didn't boost up back to 15V.

I need to unplug an plug-in again to get the 15V.

Or any command I can reset the connection on the second port to let the PD negotiation setup again after I set the Dead Battery Flag to be false?

And one more thing I want to confirmed that this 2 project only has the difference on the number of PDOs on Transmit Source Capabilities.
project10 has 9V, 12V, 15V, which is possible to output 15V for iPad for fast charging.project10.pjt

project 11 has 15V only on Transmit Source Capabilities, at the first beginning, the iPad will draw 5V, 2A. And try to boost to 15V. And just like mention as above, the PDO_0, D27 LED flash once and go off. Then it goes back to 5V, 2A, just like an infinite boot loop.project11.pjt

It shouldn't happen as I just remove 9V and 12V on the Transmit Source Capabilities. It should still provide 15V, am I correct?

project12.pjt
And I try to rearrange the order from
9V, 1.5A
12V, 1.25A
15V, 1A

to 

15V, 1A,
12V, 1.25A
9V, 1.5A

Now, it didn't work again.

Hello,

Luca L said:

So, I would like to ask is there anyway I can power up the 15V device from the VBUS and output 15V PD at the secondary port when boost up with a 15V PD input?

My understanding is that this should work.  There are some potential issues when the sink path negotiates a lower voltage and attempts to source a higher voltage on the other port, but this is not the situation you are testing.  Can you determine if there is a hardware issue with the 15V on the external power path that is less than 15 volts at the buck and consequently less than 15 volts at the source path?

Regards,

Chris

Hello, Chris,

Yes, some how the 15V is working. I am quite frustrate on why changing the order of PDOs make it didn't work. But that's not a huge concern for me because what I need is put 15V on all VBUS, and it did at the moment.

I get quite close to what I want now. Great thanks for your helps!

Is there any mean I can set the dead battery flag to be false at start up without external source of power? Or in a normal hardware is capable to do so?
Does the BusPower Dip Switch setup help something?

As either port will be the only power input in my device which I can't have a pre 3V3 first. So I can't set the dead battery flag as false when boost up.

And since the cable have been plug in to the iPad, so it is not able to setup the PD negotiation again. After I send the dead battery flag to be false fall behind the main controller wake up, the iPad stay at 5V, 0.9A.

Hello,

Luca L said:

Is there any mean I can set the dead battery flag to be false at start up without external source of power? Or in a normal hardware is capable to do so?
Does the BusPower Dip Switch setup help something?

No.  This device was originally intended for notebook applications and you can find in Intel reference designs.  The dead-battery feature is specific to that end equipment and you cannot disable.  The operating procedure was/is from dead-battery the PD would provide power to the system to charge a dead battery and once the system has sufficient charge and the embedded controller is properly booted, then the embedded controller would send a 4cc command to the PD to tell it to leave the dead battery mode (clear the dead battery flag).  

For the case with the iPad, i would think you would need to connect the 15V first to port A and then the iPad to port B.  If you first connect the iPad, then I think that the PD would try to sink power from the iPAD (i do not know if that is possible).   Do you have another 15V sink capable device to test with?  Is the cable to iPAD have type-c on both ends?

Regards,

Chris