This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Tool/software:
Hi,
I am currently working on board design with TPS25751SRSMR on our custom board for PD application with battery charger BQ25792. This PD controller is suppose to be pre-configured for this battery charger and I was told before that no such firmware is required if we are going to use these two together. Please help me to clarify these 2 points:
1. Can you please confirm that if ADCIN pins that are suppose to be configured on each power ON or this is only required for the very fist time? I am asking this as we would like to not add any EEPROM on-board and would like to use USB DP/DN connected between PD controller and USB-C to be configured via TI customization tool.
2. Please note that we are not adding any external embedded controller but as per this configuration table "Always Enable Sink" is supported when we have external embedded controller, the "Negotiate High Voltage" is not valid to use with any supported battery chargers and "Safe Mode" is only if we have EEPROM. To me it looks like Negotiate High Voltage is the one to go with but I am confused when it states that "This configuration is not valid to use with any supported battery chargers". Please clarify and help me to use the correct configuration based on our application.
Please note that this is our intended use with only PD controller and battery charger without and EEPROM or External controller:
Kind regards,
Mat
Hello TI,
Any update on above post would be appreciated and it will be helpful for us.
Thanks
Hi Muhammad,
TPS25751 does not have any pre-configured settings to be compatible with BQ25792/8 out of the box. The TPS25751EVM has a pre-configured settings that allows for basic 5V source and up to 20V sink, however even then its configuration is stored on the EEPROM that's also on the EVM hardware itself.
TPS25751 requires a configuration to be loaded which can either be stored in a EEPROM or loaded from an external controller. The PD configuration itself is configurable and generated through the USBCPD Application Customization Tool which can be found here: https://dev.ti.com/gallery/search/usbcpd
1. Can you please confirm that if ADCIN pins that are suppose to be configured on each power ON or this is only required for the very fist time? I am asking this as we would like to not add any EEPROM on-board and would like to use USB DP/DN connected between PD controller and USB-C to be configured via TI customization tool.
The ADCINx pins are for configuring the device (TPS25751) I2C target address (0x20 through 0x23) as well as its dead battery configuration (how the PD behaves before a configuration is loaded). You can only use the "Flash to device from current configuration" option with the TPS25751EVM and not your own custom hardware that has TPS25751, that is because the TPS25751EVM has a TIVA microcontroller with internal firmware to directly communicate with the GUI. You can generate a full flash binary (for EEPROM) or low region (for EC) file that contains the PD configuration.
2. Please note that we are not adding any external embedded controller but as per this configuration table "Always Enable Sink" is supported when we have external embedded controller, the "Negotiate High Voltage" is not valid to use with any supported battery chargers and "Safe Mode" is only if we have EEPROM. To me it looks like Negotiate High Voltage is the one to go with but I am confused when it states that "This configuration is not valid to use with any supported battery chargers". Please clarify and help me to use the correct configuration based on our application.
As mentioned before, the PD configuration needs to be either loaded via EEPROM or EC. If you choose to use an EEPROM then it's recommended to use SafeMode, otherwise with an EC you should use AlwaysEnableSink. These dead battery configuration describes the PD behavior prior to have a config loaded (the PD Mode reg 0x03 reads back PTCH). NegotiateHighVoltage is not recommended as it requires several levels of EC logic in order to be implemented correctly.
Let us know if you have any further questions or concerns!
Thanks and Regards,
Raymond Lin
Hi Raymond,
Thanks for the detailed answer.
If TPS25751 does not have any pre-configured settings to be compatible with BQ25792/8 out of the box then how can we use this PD chip on our custom hardware? What I understand is that in order to use this PD for our custom board we either have an EC or the External flash that will configure the PD configurations via I2C.
In this case if we want to exclude the TIVA and add the EEPROM then can you please tell me how and which interface (I2C/USB) we will be using to program the flash on our custom board with TPS25751 and BQ25792/8? I believe the flash will be on our custom board and connected to the PD.
You said that "You can generate a full flash binary (for EEPROM) or low region (for EC) file that contains the PD configuration." In this case if PD configuration are limited to Eval board then how we can use it on custom board. I am just trying to understand with respect to our application.
I did check the Eval board where the TIVA is connected to PD controller and EEPROM via I2C and then TIVA is communicating to the USBCPD Application Customization Tool via USB interface.
Kind regards,
Muhammad Awais
Hi Muhammad,
The Application Customization Tool is for generating a PD (TPS25751) configuration in the form of a full-flash binary for EEPROM systems or low-region binary for EC systems. The EVM with the on-board TIVA allows for easier evaluation of the TPS25751 module without needing to go through the process of loading a configuration via binary files.
For custom hardware, you'll need to include one of the followings for loading PD (TPS25751) configuration:
1. a 64kB (512kb) EEPROM connected to the I2Cc pins of TPS25751, recommended to pair with 'SafeMode' dead battery configuration. Upon boot-up either through VBUS or VIN_3V3, TPS25751 will read for I2C target address 0x50 and load the configuration from the EEPROM (assuming a valid config is stored).
2. an EC connected to the I2Ct pins of TPS25751, the EC will need to load the PD configuration upon boot-up using the Patch Burst Mode (PBMx) sequence documented in the TPS25751 Technical Reference Manual. For EC loading config system it's recommended to pair with 'AlwaysEnableSink' dead battery configuration.
Without a configuration loaded (no EEPROM or EC), TPS25751 will remain in PTCH mode (patch mode, waiting for a configuration to be loaded. Refer to register 0x03 for details) and will not operate. As mentioned before, TPS25751 does not come with any pre-configured settings to work with BQ25792 out of the box since TPS25751 also supports integrated I2C control for several different BQ devices. The Application Customization Tool allows for user to easily generate a firmware image based on a few easy questionnaires as well as "advanced configuration" for further configurability (i.e. add or remove source/sink PDOs, power role preference, GPIO configuration, etc.).
Let us know if you have any further questions or concerns!
Thanks and Regards,
Raymond Lin
Hi Raymon,
Thanks, I have checked the Application customization tool. May be the "Full flash binary" would be the best way for us. I think we may use the EEPROM programmer to connect it via I2C by using jumper setting and disconnecting the PD and once the EEPROM is programmed then we may switch the I2C path to PD controller via jumper. I haven't checked the programmers but I think this should work.
Kindly let me know if you have any recommendation/reservation on this method?
Thanks and Regards,
Muhammad Awais
Hi Muhammad,
After loading the EEPROM with a new configuration you'll need to power cycle TPS25751. TPS25751 only looks for an EEPROM (with I2C address of 0x50) upon booting up.
Also you don't necessarily need to have a jumper to disconnect the I2C lines between the EERPOM and PD when flashing, as mentioned all you need to do to ensure the new configuration is loaded properly is by power cycling the PD controller after a new config is loaded onto the EEPROM. You can refer to the TPS25751EVM schematic for reference (in the EVM case, the TIVA MCU is the EEPROM programmer).
Let us know if you have any questions or concerns!
Thanks and Regards,
Raymond Lin
Thanks Raymond,
Got it and by power cycle I believe we need to remove the power and then power it back so that EEPROM contents that were uploaded will be uploaded to the PD controller. Please correct me if this is not the case.
I have another separate questions that if I would like to go with this profile where I might need to source either 5V (locally generated with 3A) or higher power via BQ from the battery then how it will be selected by the PD controller. I am assuming the sink side has to tell PD controller via CC pins about the power requirement and then PD internally either provide via 5V or the PPHV path from BQ?
Kind regards,
Muhammad Awais
Hi Muhammad,
Got it and by power cycle I believe we need to remove the power and then power it back so that EEPROM contents that were uploaded will be uploaded to the PD controller. Please correct me if this is not the case.
Yes you're statement is correct here. If you have a new configuration loaded onto the EEPROM you'll need to power cycle TPS25751 in order for the new configuration to take effect.
I have another separate questions that if I would like to go with this profile where I might need to source either 5V (locally generated with 3A) or higher power via BQ from the battery then how it will be selected by the PD controller. I am assuming the sink side has to tell PD controller via CC pins about the power requirement and then PD internally either provide via 5V or the PPHV path from BQ?
You can configure TPS25751 to either source 5V through PP5V or through PPHV path from BQ. By default when you select a PD+BQ option, the GUI will automatically configure TPS25751 to source 5V through the PPHV path from the BQ part. If you prefer having a dedicated 5V/3A source path from PP5V instead you can make the configuration change through Transmit Source Capabilities (0x32)/Source PDO1 and set Power Path for PDO 1 [9:8] from 'PP3 Source this PDO (0x2)' to 'PP1 Source this PDO (0x0)'. PP1 refers to PP5V and PP3 refers to PPHV in the GUI tool.
For design reference you can refer to PMP41062, this design uses TPS25751 with BQ25756 but the overall design can also be applicable for other supported BQ parts. https://www.ti.com/tool/PMP41062
Let us know if you have any further questions or concerns!
Thanks and Regards,
Raymond Lin