TPS65892 PP_HVE Sink Issue

When I reduced the cap on the SENSEP pin, the shorter time was needed to negotiate again but still can't be negotiated when there is voltage on the SENSEP pin.

is this expected behavior?

Hi Andrew,

Does the HV_GATE1 turns on after the voltage at SENSEP goes down below 3V?

Can you scope HV_GATE1 & HV_GATE2 and SENSEP when this issue happens and share it?

Thanks,

Rahul

HV_GATE1 turns on when I connect the cable at SENSEP goes down below 1.2~1.3V. 

I have attached related scope captured images and schematic. 

please review this.

Thanks,

Andrew2783.HV_GATE Issue_TPS65982.pptx

Hi Andrew,

When in dead battery the TPS65982 will automatically have the reverse current protection set. This is done because we are closing the switch from VBUS to the system and must protect VBUS from any voltage from going into VBUS from the system. Almost every system will discharge the system power (SENSEP). Is there a specific reason why the system has residual voltage? Huge capacitance? Light system loading?

Is this a notebook application?

Jacob

Hi Jacob, 

the system has light loading when the plug is detached. 

negotiation is available when the voltage of SENSEP is lower than 1.2V. but this voltage is discharged slowly on the customer's notebook application. 

can we adjust this level to higher value so that this platform doesn't need to wait some time to be negotiable again? or disable this function?

it is hard to modify HW at this moment. please review this.

Thanks,

Andrew

Hi Andrew,

I checked the boot code and it look like the device shouldn't reload the flash but it will still prevent the reverse current from flowing into VBUS. I will have to double check this to confirm.

I am curious about the VIN_3V3 supply to the device. Do you have a plot of that supply during this condition?

This may be slightly complicated to achieve but would you be able to get a Boot Status read during this condition as well?

Jacob

Jacob, 

this only happens on dead battery situation. 

and the ACE load FW from the flash properly and negotiation is done when I see the PD log. and 20V is on VBUS already. 

it is just that HV_GATE1 is not driven  when SENSEP is above 1.3V. 

and we want to check this if we can adjust the allowed level higher than 1.3V. you can check the attachment on the link in this posting. 

/cfs-file/__key/communityserver-discussions-components-files/138/1425.HV_5F00_GATE-Issue_5F00_TPS65982.pptx

Thanks,

Andrew

Thanks,

Andrew

Hi Andrew,

I will need the firmware that you are using to check out on my side. Can you attached the Configuration Tool Project?

I need to verify what the hardware registers are doing this condition before I can let you know that we can adjust the threshold.

What is being accomplished by this on the BUSPOWERZ pin? If they are sinking power through PP_EXT in dead battery this pin has to be tied to GND.

Jacob

Jacob, 

the BUSPOWERZ pin is low when the dead bat mode on the LG Notebook board. i checked by my self.

I have attached FW pjt file of TPS65982 for this TBT PC project. please refer to it.

161011_Final.pjt