Both SAFE_5V_EN and VBUS_EN are HIGH, can't get SAFE_5V PFET to Turn On When 5V Source Is Connected

[definededits]

Hi,

is there any setup required to get SAFE_5V PFET enabled? When connected with 5v USBC or USB A, the gate driver is 5v (PFET is OFF). 

I2C PD_STATUS bits:

UsbController.cpp: 59: onStatusTimerExpire(): VBUS voltage is 49
UsbController.cpp: 62: onStatusTimerExpire(): BCR_CFG=0x0 DATA_ROLE=0x0 POWER_ROLE=0x0 CONTRACT_STATE=0x0 SINK_TX_RDY_STATUS=0x1 POLICY_ENGINE_STATE=0x1 PD_SPEC=0x2 PARTNER PD_SPEC=0x0 UNCHUNKED=0x0

Please let me know what information I need to provide.

Regards

[Kieran_Pan · Accepted solution]

Hello,

Could you please tell  if you use CYPD 3177 in our EVK and which EVK you use?  CY4533?
How do you connect your device?

You could find the definition and condition of VBUS_FET_EN and SAFE_PWR_EN in the datasheet.

VBUS_FET_EN is enabled when the EZ-PD BCR device successfully negotiates a power contract within the requested range
SAFE_PWR_EN is enabled when the EZ-PD BCR device fails to negotiate for higher power and defaults to 5V.

Best regards,
Kieran

[definededits]

Hi I am using the CYPD3177 with a custom board. This is how it is connected. I think my SAFE fet is wrong, but I am confused why I have 5V on the SAFE_PWR_EN pin? When connected with USB A, we should fail to negotiate power contract and set the SAFE_PWR_EN pin to LOW right? This is not happening for me. 

Is there any other condition that would cause SAFE_PWR_EN to be high? 

[Kieran_Pan]

Hello, 

You can follow the problem in your case system. I think that you could get more information through the Infineon-EZ-PD_BCR_HPI_SPEC which has many commands that could help you check the status of the chip.

Best regards,
Kieran