Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

USB EZ-PD™ Type-C Forum Discussions

GrCa_1363456
Level 5
Level 5
First comment on KBA First comment on blog 250 sign-ins

Which USB PD Controllers, CCG or PMG, contain the logic to support Attach Detection Protocol (ADP) to detect a connected device then accept power from (sink) or provide power to (source) the connected OTG device without the benefit of a cc signal?

Stated differently; USB OTG Devices that interface through a four wire USB micro or USB A connector, may be connected via a physical adapter to a USB-C interface controlled by an Infineon USB PD Controller. Can Infineon's USB PD Controller support OTG devices?

"ADP operates by detecting the change in VBUS capacitance that occurs when two devices are attached or detached. The capacitance is detected by first discharging the VBUS line, and then measuring the time it takes VBUS to charge to a known voltage with a known current source. A change in capacitance is detected by looking for a change in the charge time."
Reference Section 5.4.1 of the USB "On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification" Revision 2.0 version 1.1a July 27, 2012

Greg

 

0 Likes
1 Solution
Wang_Fred
Moderator
Moderator
Moderator
100 replies posted 10 likes received 25 solutions authored

Hi Greg,

According to your description of Attach Detection Protocol (ADP) device, I believe USB PD controller, CCG or PMG can not support it, since either attach/detach or power contract negotiation depends on the divided voltage/message interaction on cc line. 

Any behavior within scope of Type-C Spec and Power Delivery Spec can not conducted without cc line involved.

 

Thanks, Fred

View solution in original post

0 Likes
1 Reply
Wang_Fred
Moderator
Moderator
Moderator
100 replies posted 10 likes received 25 solutions authored

Hi Greg,

According to your description of Attach Detection Protocol (ADP) device, I believe USB PD controller, CCG or PMG can not support it, since either attach/detach or power contract negotiation depends on the divided voltage/message interaction on cc line. 

Any behavior within scope of Type-C Spec and Power Delivery Spec can not conducted without cc line involved.

 

Thanks, Fred

0 Likes