TPS65988: Cannot get TPS65988DH to charge phone using 87 emulation mode

Jordan Restifo

Part Number: TPS65988
Other Parts Discussed in Thread: TPS65987D, , TPS65987

I have a TPS65987D EVM which I configured as UFP, with role swap to allow charging at the same time. This works well for me. Please see attached project file.TPS65987EVM.pjt

However, this part is hard to obtain right now so I switched to a TPS65988DH intending to use it in 87 emulation mode. I made a new project file, duplicating the settings from my TPS65987 project where possible. I turned on 87 emulation mode. I also have the jumpers arranged as per the TPS65988 EVM user guide. (See attached photo).

I am also attaching my TPS65988DH project file. Essentially, when I plug in a phone to Port A, I see no voltage on VBUS (P5V test point measures 5.0V), it doesn't seem a negotiation occurs and the device does not charge. What am I missing / what did I configure incorrectly? Thank you!

87_TPS65988DH.pjt

over 4 years ago

0 Kedar_Sirdeshpande over 4 years ago

TI__Expert 3370 points

Hello Jordan,

Based on your TPS765987 configuration, a UFP is typically a SINK only role. I just tested both your configuration files and I don't see a contract with both if the port configuration is UFP.

Either set it to DRP / DFP and allow corresponding role swaps in the configuration so that your end port role can be achieved.

Regards,
Kedar

0 Jordan Restifo over 4 years ago in reply to Kedar_Sirdeshpande

Prodigy 110 points

Oddly enough, with my TPS65987EVM, UFP with a role swap for power does work. I can confirm that using DRP with role swaps works with the TPS65988 EVM. Odd, I suppose there must be some difference either in my config I didn't catch or in the 87 emulation on the TPS65988. In any case, this did resolve the issue for me, thank you.

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TPS65988: Cannot get TPS65988DH to charge phone using 87 emulation mode