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USB EZ-PD™ Type-C Forum Discussions

GrCa_1363456
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CYPD2122 is not working in dead battery mode (won’t power up) unless CC1 is connected to the Rd pin and then only in one orientation unless an external Rd is connected to CC2.

Non-functioning is expected behavior and documented when CC1 is NOT connected to the RD pin.
However, if the connector is flipped, it won’t power up with no Rd on CC2. Is this the expected behaviour?

CYPD2122 will only power up if the cable is oriented one way and CC1 is connected to the Rd pin.
If an external 5.1Kohm resistor to GND is added on CC2, the dead battery mode (powers up) works for either cable orientation.
If an external Rd is added, is there a concern with too low of a resistance on CC2 if the internal Rd applied to CC2 is activated (causing two Rd’s in parallel).

An option may be to add the FET structure externally for the dead battery Rd proported to be internal to the CYPD2122. I'd prefer not to add external dead battery logic if internal dead battery logic internally should be working.

Reference: Section 8.3 of AN210403, Hardware Design Guidelines for DRP Applications Using EZ-PD USB Type-C Controllers.

Greg

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ShifangZ_26
Moderator
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Hello Greg,

 

The CC2 have Rd, but it is not have dead battery Rd. The CC signals shall be the one have Rd on CC line.  So that the Type-C receptacle shall be responsible to identify which line have Rd if it is Power Source Role. 

 

Best Regards,

Lisa

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ShifangZ_26
Moderator
Moderator
Moderator
10 likes given 250 sign-ins 1000 replies posted

Hello Greg,

 

The CC2 have Rd, but it is not have dead battery Rd. The CC signals shall be the one have Rd on CC line.  So that the Type-C receptacle shall be responsible to identify which line have Rd if it is Power Source Role. 

 

Best Regards,

Lisa

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