Hello, my name is Brian Fetz. I'm an engineer at Keysight Technologies. In this short video,
I'll introduce you to an exciting development in the industry - the USB Type-C connector.
It is is low provide and orientation independent. It sports many pins for broad applicability
and supports high current charging. As if that wasn't enough, it also allows multiple
protocols such as USB 3.0 and 3.1, DisplayPort and Thunderbolt.
Let's start with the USB Type-C signal plan.
The first thing you'll note is that the interface is symmetrical. On either side we have ground
pins. Towards the interior we have Vbus pins. This allows for the high current charging
specified up to 5 A.
The next thing that you'll note is that there are two pairs of Tx/Rx differential lines.
We'll call those port 1 and port 2, respectively. You'll note that if you flip the interface
over, Tx2 lines will land exactly on the Tx1 lines, and the Rx2 lines will land on the
Rx1 lines.
In the interior of the interface you'll see that we have USB 2.0 lines and they are duplicated,
there are two D+ and two D-. These are actually cross-connected at the receptacle in the interface.
There's a pair of utility pins, SBU1 and SBU2. These are used for alternate interfaces other
than USB 3.0 and 3.1. They're used for DisplayPort as well as Thunderbolt.
The magic of the interface are the CC lines, denoted here as CC1 and CC2.
You'll see that on CC2, we have a pull-up resistor to Vc. The same is true on CC1. This pull-up
resistor is sensed to determine if there is a load on the other end, namely RD on the
device. When that is sensed, then it knows that the particular port that that CC line
is connected to is active. In this case, it's CC2, means that port 2 on the host is active.
Since I have this shown that CC2 on the device is connected, then port 2 on the device is
active as well, and you'll see we have a direct connection and the link will be determined
on those two.
If you should flip the cable over at the device, then CC1 will be connected to the CC2 of the
host, and now port 1 of the device will be connected to port 2 of the host. That's how
it gets its orientation independence.
You'll notice on the interior of the cable, I have resistor designations RA, and when
a cable is connected, one of the CC lines will be connected to this RA termination and
it will indicate that that CC line is to power the cable locally. The CC line, upon connection,
will become Vconn. Vconn is a voltage source for the cable for that local port, but does
not go through. The cable only has one CC line, and that's how the orientation is determined
for the link.
It is a sophisticated interconnect that requires high bandwidth. In this case for USB and for
DisplayPort 20 GHz, 30 GHz for Thunderbolt as you press 20 Gbits/second through that
interface. There are two Rx/Tx pairs - so both of these need to be considered in a validation
plan. If the device that you're manufacturing has different protocols such as DisplayPort
as well as USB or Thunderbolt, than those protocols need to be tested as well.
When you are powering up the device initially, you'll need a means to control the CC signal
through the RP, RD and RA terminations and this helps in debug and is also useful in
test for control of the ports.
You'll need a means to observe the CC lines, Vbus and the SBU lines if you are using an
alternate mode. You also need a means to communicate over the CC line the requirements of power
in the link. Vbus can be set up for your device as a consumer or a provider, and it may have
different voltage or current requirements and that may need to be negotiated through
a power delivery controller. Also if you're testing an alternate mode, you'll need to
be able to get that device into the alternate mode and that has to be done over the power
delivery channel as well.
As power delivery is incredibly important in this interface, you'll need to be able
to test the communication channel, that is the line over the CC, its protocol, and the
Vbus profile.
If you'd like to have more information on Keysight's Type-C solutions, please visit
our web-site. Thanks for watching.