TPS25730: Implementation Review /Questions

I should add, the Capacitance on the PPHV output is limited in the screen shot as there is another 30uf on the charger input and they are placed /routed extremely close to each other 

Hi Johann, 

Thank you for reaching out!

We will review and get back to you with feedback early next week. 

Best Regards, 

Aya Khedr

Okay thank you 

Hi Johann, 

Could you please post a more clear schematic image or PDF? 

Best Regards, 

Aya Khedr

is that better ?

Hi Johann,

The schematic is better thanks!

I will get back to you with feedback by tomorrow. 

Best,

Elijah

?

1. The Schematic look good for overall use. The external LDO is not required. 

2.  When using the TPS25730, VIN_3V3 is typically used to power the internal circuitry of the pd device. However VBUS can be used if VIN_3V3 is unavailable. If VIN_3V3 is unavailable, then the pd enters a dead-battery star up condition. In this condition, VBUS is stepped down with an internal LDO and the output is run through to LDO_3V3.

3. It is recommended that the drain pins be connected together. 

4. The SINK_EN should be pulled up to the internal LDO_3V3.

Please feel free to reach out for any more questions. 

Best,

Elijah

Thanx. So to confirm 

The schematics is setup as is with AdC1 to 4 will request 15v without software requirement due to default configuration on the adc inputs 

If the external LDO is not required, what's best practise for the VIN_3v3 input ? Unconnected? 

Im asking as down stream i will.have a 3v3 regulator that can power the chip if needed but for optimal current consumption I suspect that this chip when USB is not present can be powered down since we running off the battery.

Also here is updated version

1. I have reviewed the current schematic and made comments on the pin connections. One thing to note is that the resistor divider configurations will need to change in order to meet your specifications. Please refer to attached document for the comments and resistor configuration table.

2. Since the external LDO is not required, it is recommended to tie VIN_3V3 to ground when unused. This will allow for optimal current consumption. Schematic Checklist Rev.xlsx

Hi Elijah, thank you for the check list, I made some of the changes but need to confirm others 

1. ADC1 was a mistake on my part- I fixed that but the other 3 dividers were decoding correctly according to me unless I'm missing something else ?
2. The output capacitance on the PPHV pins looks low because it closes connects to the charger input that already has 30uf- added and additional 10uf now 
3. I have TVS on all the pins connection from the USB c connector, are you suggesting adding ESD in addition ? I have extremely limited board space available and forced to move to 0201 for some of the parts so I'm trying to avoid as much as possible. 
4. The remaining GPIO will be connected to MCU 

Hi Johann, I still see some issues. 

1. The ADCx values are still not being decoded to the correct values. The formula for the ratio is Rdown/(Rup + Rdown). Table 8-1 attached to the previous excel should help.

2. The additional capacitance will suffice. 

3. Adding ESD protection is optional but recommended. It is highly recommended that ESD protection be added to the CC lines. 

4. If the MCU will handle the pull up resistor then the GPIO pins will suffice. If not, the "PLUG Event" pin should be tied to LDO_3V3 or to ground if unused. The "DBG_ACC" pin should be tied to LDO_3V3 or to ground if unused.