TPS65988DJEVM: Evaluation board for TPS65988, TPS65988EVM not available?

Thank you Aya. I currently only have the “DJ” development board. But I am designing for use with the DK variant. I tried one of the example applications (which actually uses the DH variant) and in doing so have replaced the firmware on the DJEVM board. It was F807 and I replaced it with: TPS65987_88_F707. My results were not as expected (I will have to go back to double check everything again). But would the firmware i used (F707) work ok on the TPS65988DJEVM board (which originally came with F807)?

Hi Aya,

The Application Customisation Tool didn’t seem to have the right recovery bin file, but I had backed it up before. I flashed it and was able to recover it. Thank you for your suggestion.

After further thought, the DK version supports Thunderbolt 4 which we won’t be using. Our design is not data heavy. We have an internal battery that needs to be managed in a UPS style configuration. So now I’m leaning more toward the DH version. Is there a reason why the DH version is not recommended for new designs? I would be testing out the DH configuration on the TPS65988EVM board instead. Please let me know if you have any comments or concerns. Thank you. 

Kind regards, 

David 

Hi David, 

The DK variant was previously intended for Thunderbolt/Intel reference designs only. We are now recommending the DK variant for all new DisplayPort applications. DK provides fixes from DH and also supports a newer version of the PD specification (PD3.1). 

What is your end-application? Does it require DisplayPort support?

Best Regards, 

Aya Khedr

Hi Aya,

An assumption I had was, bug fixes in the newer version: DK (vs. DH). I am however unsure on how that may affect our final design. We will not be implementing display port support. The units main purpose is power delivery. Here is the general power scheme for our unit:

• Unit should be powered by mains when available.
• Unit should be powered by battery when mains is not available
• therefore this will be a UPS configuration.
• Unit should power an iPad (from the battery) when mains is not available.
• Unot should be able to handle a complete power loss, power surges, as well as brown-out events.
• Unit should be able to handle short circuit protection, over-voltage, under-voltage, over-current and over-temp conditions.
• When mains power is available the battery should be maintained at a full state of charge.
• When mains power is available and an iPad is plugged in, the battery or iPad should be prioritised based state of charge.
• Either USB port could be used for powering up the unit. 
• Either USB port could be used to charge the iPad.
• Either USB port could be used to communicate UART (serial) data.
  

Thank you for your prompt and helpful responses. 

David

Hi Aya,

Thats a good suggestion as it ticks off most of our requirements. One of the issues that we have to address are brownouts as they can have an adverse effect on the onboard microcontroller. The TPS65988 has robust power management features that would seem to address this. I don’t see that featured in the TPS25751 controller and I’m not sure how it well it can handle a poor power environment. Thank you.

Kind regards,

David Veloz 

Hi David, 

Which feature are you referring to on the TPS65988 in particular? 

Best Regards, 

Aya Khedr

Hi Aya,

here are some excerpts that I think may apply: 

Power management
• Power supply from 3.3 V or VBUS source
• 3.3-V LDO output for dead battery support

As well as: Fast role swap request detection voltage thresholds.

HI David, 

The TPS25751 supports booting from dead-battery conditions by receiving power from VBUS. See more in section 8.3.2 Power Management in the datasheet. 

David Veloz said:

As well as: Fast role swap request detection voltage thresholds.

Does your design require Fast Role Swap support? What is the end-application (USB-C Dongle?)

Best Regards, 

Aya Khedr 

My understanding of fast role swap is that if the power is suddenly unplugged from the 2 port unit, the TPS65988 controller can fast role swap from being a sink to a source. The unit contains a microcontroller (which is very sensitive to power fluctuations) and the unit could also be providing power for devices (either an iPad or a very small thermal printer on its 2nd port). The unit contains a battery which can provide the power for the units operations (microcontroller, stepper motor) as well as a source of power for the external devices plugged in as mentioned above. 

Thanks Ghouse, the TPS25751 data sheet doesn’t seem to make mention of this and just wondering if the TPS25751 supports this feature. 

Thanks for answering all my questions. From our case use, is there any reason why I shouldn't use the DH variant? Other than it is an older ROM revision. 

Kind regards,

David 

Hi Aya,

Finally, I’ve got a question regarding my development boards. I have the TPS65988EVM, which uses the TPS65988DH IC, as well as the TPS65988DJEVM, which has the TPS65988DJ IC installed.

I’m planning to swap the DJ IC with the TPS65988DK. The two boards have slightly different configurations, so once I’ve replaced the DJ IC, I’ll need to take a closer look at the settings. My question is: would it be possible to develop for the DK variant on either board—the DH-based EVM or the modified “DK” EVM? Thank you in advance.

Kind regards,

David