TPD6S300A: removing VBUS power when CC to VBUS short circuit

Toshiro Imi

Part Number: TPD6S300A
Other Parts Discussed in Thread: TPS65987D

Hello,

Our customer has developped USB-C Sink port design by using TPD6S300A for protection device. Then he has a question how he can make a scheme of removing VBUS power in fault event such as VBUS to CCx short circuit.

Since this case is Sink application, I think it cannot be achievable as long as a Source side power is active. Would you suggest any idea or experiences for this case.

Best regards,

11 months ago

0 Tommy Lin 11 months ago

TI__Mastermind 19215 points

Hi,

Depends on what PD controller you use for the sink port, you will need to connect the /FLT pin to

a) one of the GPIO that can be configured as disable VBUS input event. or,

b) if there is an EC on board connect /FLT to EC and let EC to tell the port to disable VBUS

Regards

0 Toshiro Imi 11 months ago in reply to Tommy Lin

TI__Expert 6260 points

The customer uses TPS65987D as PD controller. I am curious how we can kill VBUS input power in SINK side. Even though /FLT connects to TPS65987D, I suppose VBUS power supply could not disable because this is SINK, port not control VBUS vis CC pin due to CC to VBUS short circuit. Does it mean D+ or D- is able to disable VBUS power on SOURCE side.

Best regards,

0 Tommy Lin 11 months ago in reply to Toshiro Imi

TI__Mastermind 19215 points

Hi,

TI US is out of office in observance of Memorial Day.

I will get back to you tomorrow.

Regards.

0 Tommy Lin 11 months ago in reply to Toshiro Imi

TI__Mastermind 19215 points

Hi,

TPS65987D will disable the power path inside therefore disconnect the system from the port.

Regards

0 Toshiro Imi 11 months ago in reply to Tommy Lin

TI__Expert 6260 points

Hello,

Let me summarize how it works as follows.

1. CC is short circuited to VBUS.

2. TPD6S300A cut off CC path, and is asserted /FLT=Low to TPS65987D GPIO

3. TPS65987D cut off VBUS.

Though CC is still in short circuit state to VBUS on UBB-C connector and Source supplies VBUS power on CC pin because this is Sink, system is protected CC over voltage state by cutting off CC pin to CC on PD controller side by TPD6S300A.

Is my understanding correct.

best regards,

+1 Tommy Lin 11 months ago in reply to Toshiro Imi

TI__Mastermind 19215 points

Hi,

Yes that is correct.

Regards

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TPD6S300A: removing VBUS power when CC to VBUS short circuit