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TPS25750: Schematic review request and a few questions (TPS25750 + BQ25792 + TPD6S300)

Tomasz Plewa
Prodigy 10 points
Part Number: TPS25750
Other Parts Discussed in Thread: BQ25792, , TPD6S300, TPS54531, TPS25751, ADS1262, TPS54120

Tool/software:

Hello Sir/Madam

Please help us to check our schematic (attached as pdf), we are using TPS25750 + BQ25792 + TPD6S300 solutions.

USB_PD_v1_0.pdf

I created the schematics based on available documentation and comments from this forum. However, I have a few questions whether everything is done well and whether something can be done better.

The device is to be powered by USB (with 3S battery charging) and enable operation of connected devices in Dual-Role mode (communication with a computer and pendrive/HDD/optional accessories - USB 2.0).

Here are my questions:

1. Is it correct to connect the USB 2.0 differential lines and will it enable communication and PD + BC support ?

2. Can the FLT output of the TPD6S300 be somehow integrated with the TPS25750 ? Do I have to do it myself via the microcontroller in the device ?

3. How to better implement the TPD6S300 power supply ? How is it currently with the 3.3 V LDO in TPS25750, or maybe from the P3V3 power line (TLV75533) ?

4. The forum topic mentioned below mentions possible problems with too large capacitor capacities on the PP5V power line:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1283381/usb-pd-chg-evm-01-configuration-gui-issue-for-tps25750-bq25798

Quote from the above-mentioned topic:

"The reason we proposed removing some capacitance (C27 and C28) was that high capacitance on PP5V could cause RCP to fail. Since the TPS25750 relies on RCP to prevent PPHV voltage from being seen on PP5V during power path switches, a failure of RCP could have been the issue. High capacitance would mean slower charging of the caps, which will cause the TPS25750 to see RCP later, potentially too late. Once the PP5V switch opens with 9V already seen, we do not have a way of quickly discharging it, so OVP would be triggered."
 
Can I ask for suggestions on what to pay attention to to avoid this problem ?
I will mention that I intend to use the PP5V power line through additional 3.3V LDO stabilizers to power the device's processor (ARM Cortex M7) and to power the TFT display backlight (5V).
The voltage for the PP5V line comes from the TPS54531 DC/DC converter (5A), so I have some reserve current here that I can use. I hope this is not a problem ?
 
5. Reading other entries (e.g. those listed below), I see that there are some problems with TPS25750/TPS25751. Is there any Errata for DS to find out what to expect, or do you have to browse through such threads here or check it experimentally in your own project ?
 
https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1300538/tps25751-tps25751-development-problems
https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1360074/tps25751-development-problems
 
6. I need to generate 6V from the VSYS power line. The voltage will be needed to power the LDO (high PSRR/ultra low noise) stabilizers that power the ADS1262 32bit analog-to-digital converter. The digital part of the ADC will be powered by 3.3 V and the analog part by 5 V. I want to make the best use of the mentioned ADC, so I need a good power supply. Can I ask for some suggestions as to which DC/DC converter integrated circuit is best to use for this purpose ? Using the search I found the TPS54120 integrated circuit, is this a good option or is it better to use something else. TPS54120 is a 1A converter, so much more than I need to power the ADC.

The part with the ADC converter will be practically identical to the solution proposed by TI "Design guide: High-Resolution, Low-Drift, Precision Weigh-Scale Reference Design (Rev. A)"

https://www.ti.com/lit/ug/tiduac1a/tiduac1a.pdf?ts=1716611908749&ref_url=https%253A%252F%252Fwww.ti.com%252Fsolution%252Fweigh-scale

I will be grateful for suggestions on how to best implement the ADC power supply.

Looking forward to your feedback.

Thanks a lot.