CYPD3177 Going Directly into Fault

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pgrinalds
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Hi all! I am student working on adding PD to my amplifier PCB. I painstakingly made my schematic and pcb based on the application note, eval board, and other users' designs. But as soon as I plug in the power jack I goes into fault. I specified the resistors to provide at least 9v with a maximum of 20V at 3.75A. I feel like the design is pretty straight forward so I am not sure what I missed. Any thoughts at all would be welcomed. I've attached the schematic below.

cypdschema.png

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HmdRahmathulla
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Hi @pgrinalds ,

Thank you for posting in infineon community.

Remove R9 resistor to achieve maximum of 20V. what is the requested data from the sink?

if you have Protocol analyzer,please share the protocol analyzer data log.

 

Best Regards,

Mohamed Rahmathulla

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HmdRahmathulla
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100 solutions authored 250 sign-ins 25 likes received

Hi @pgrinalds ,

Thank you for posting in infineon community.

Remove R9 resistor to achieve maximum of 20V. what is the requested data from the sink?

if you have Protocol analyzer,please share the protocol analyzer data log.

 

Best Regards,

Mohamed Rahmathulla

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Thank you so much for the reply! I will try removing R9. Is the data requested from the sink found in the protocol analyzer log? Do I access that through I2C? Or an oscilloscope? I can do either.

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HmdRahmathulla
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Hi @pgrinalds ,

it is not possible to get the log from I2C or Oscilloscope. The PD communication is happens in the CC lines of Type-C port. 

you can find the protocol analyser from the below link which is help you to analyse the CC lines data transmission.

https://www.infineon.com/cms/en/product/evaluation-boards/cy4500/

 

For Hardware,

1) you can measure the VBUS line in oscilloscope during the start-up time and check the current as well.

2) also check VDDD lines during the start-up time. this voltage will get generated from the internal LDO, it will help to check whether the IC is working as expected or not..

 

Thanks & Regards,

Mohamed Rahmathulla

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Thank you for the feedback! I did as you recommended and found that the module was requesting more current (3.75A) than the charger was capable of providing. Also lowered the min requested voltage to 5V so I could power it by computer for programming. 

Could you clarify something for me, however? Is the purpose of the voltage divider for the current to set the CC line current communication or set the device current draw or other? From what I have learned, I believe it to be a communication to verify that the host can provide a certain level of current, is that correct? And its only output from there is to enable the Fault pin if it cannot provide that much current?

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HmdRahmathulla
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100 solutions authored 250 sign-ins 25 likes received

Hi @pgrinalds ,

Yes, Voltage and Current request will happen based on the Resistor divider network in the Voltage Min and max, Isink and Icoarse pins, so the source will give the requested voltage and current to the sink.  safe power will enable incase of capability mismatch.

as you said, You can use HPI communication to change the Voltage and current request from the external controller during the Run-Time.

 

Thanks & Regards,
Mohamed Rahmathulla

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