I am evaluating the USB Power delivery protocol using the CCG3 EVK. I have the following questions regarding the power delivery profiles.
1. What is the default power delivery profile is selected during the power negotiation process?
2. When the Source/Sink switch from one power delivery profile to another?
Thanks in advance.
>>1. What is the default power delivery profile is selected during the power negotiation process?
ANS) In case of CCG3, The Sink and source will have their capabilities or the power profiles. If the power profiles match Sink requests for a particular power profile. If there are multiple power profiles that match between the source and the sink then sink chooses for highest voltage and highest current power profile which the source is capable of providing.
>>2. When the Source/Sink switch from one power delivery profile to another?
ANS) The power delivery profile will change from one to another when there is a contract renegotiation. Contract renegotiation can happen due to various reasons like when the source or the sink changes their capabilities or a reset event takes place, etc.
Thanks for your response. Can you please help us with the following clarification.
Why the CYPD3123-40LQXI_ctd_us firmware has only one PDO(5V@0.9A). Why cypress not recommend the customers to change the PDO ?
We need at least 12V@3A during sink mode. Can we create a multiple sink PDOs ranging from to 12V to 20V ?
This can be done using EZ-PD Configuration utility. Please find this utility in the below link
Please follow the below steps to change the PDO.
1. When you open the folder EZ-PD CCGx SDK\CCG3-CCG4\Firmware\projects\CYPD3123-40LQXI_ctd_us you will find a .xml file with the name CYPD3123-40LQXI_ctd_us_config. Open this file in the EZ-PD Config utility.
2. Then in the EZ-PD configuration utility you can make the changes as per your requirement, here you can add extra sink PDOs and source PDOs and change the Power profiles of the existing PDOs. After you make the changes in the utility save them in the name 'config'. By saving it will generate 3 files config.c, config.xml and config.cyacd.
3. Now take this config.c file which contains the modified configuration as per your requirement and replace this file with the older config.c which can be found in the folder EZ-PD CCGx SDK\CCG3-CCG4\Firmware\projects\CYPD3123-40LQXI_ctd_us\CYPD3123-40LQXI_ctd_us.cydsn\common
After following the process rebuild the CTD project and this project will contain the PDOs that you had configured
When used in your company's CY4531EVM I also have a question I hope you help me to solve the problem is this: EZ - PD Configuration Utility shows USB to Serial Bridge devices found, but there is no device to connect, I thought it was the chip is broken, still unable to connect EZ - PD changed CYPD3125 chip Configuration Utility, what reason is this.