AN95615 Designing USB 3.1 Type-C Cables Using EZ-PD CCG2.pdf

AN95615
Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Author: Gayathri Vasudevan
Associated Project: No
Associated Part Family: CYPD2103-20FNXIT, CYPD2103-14LHXIT
Software Version: N/A
Related Application Notes: AN95599
To get the latest version of this application note, or the associated project file, please visit
http://www.cypress.com/go/AN95615.
1
AN95615 explains the design of passive USB 3.1 Type-C cables using EZ-PD™ CCG2. This application note explains how
1
manufacturers can easily design and manufacture passive electronically marked cable assembly (EMCA) using CCG2.
Contents
Introduction
Introduction .......................................................................1
Introduction to USB Type-C Cables ..................................2
Type-C Receptacle/ Plug Interface ...................................3
Possible Type-C Cable Assemblies .............................5
USB Power Delivery ..........................................................6
SOP* Communication in USB PD ................................ 7
CCG2 Overview ................................................................ 7
EMCA Applications............................................................8
CCG2 in Passive EMCA Applications ...............................9
CCG2 Power Subsystem..............................................9
Passive EMCA with One CCG2 per Cable ................. 10
Passive EMCA with One CCG2 per Cable Plug (Two
Chips per Cable) - SOP’ Response Only.................... 12
Design Guidelines ........................................................... 13
Hardware Guidelines .................................................. 13
Firmware Upgrade Guidelines .................................... 13
Summary ......................................................................... 15
Appendix A: Other CCG2 Applications ............................ 16
Active EMCA Solution with One CCG2 per Cable –
SOP’ Response Only ................................................. 16
Managed Active EMCA Solution with One CCG2 per
Cable Plug - SOP’ and SOP” Responses ................... 17
Accessory Solution ..................................................... 18
Appendix B: Reference Schematics ................................ 19
CYPD2103-14LHXIT Single-Chip EMCA Schematic.. 19
CYPD2103-14LHXIT Dual-Chip EMCA Schematic .... 20
Document History ............................................................ 21
Worldwide Sales and Design Support ............................. 22
Products .......................................................................... 22
®
PSoC Solutions ............................................................. 22
The USB Type-C Cable and Connector Specification
defines a new sub-3-mm thin receptacle, a 2.4-mm
reversible plug, a cable that can be reversed in both
directions and enables the 100-W USB-Power Delivery
specification. The USB Type-C Specification requires
cables to be electronically marked to report their
capabilities to Type-C ports on hosts and devices. The
electronic marking is accomplished by embedding a
controller chip into the plug at one or both ends of the
cable. Key requirements for such a controller chip are low
cost, small footprint, low power, a turnkey solution, and a
flexible firmware upgrade process.
TM
EZ-PD
CCG2 (CCG2) is Cypress’s low-cost USB
Type-C Cable controller device targeted for such
electronically marked cable assemblies (EMCA, described
in section “EMCA Applications”). CCG2 is available in
1.63 mm × 2.03 mm, 20-ball WLCSP and 2.5 mm × 3.5
mm × 0.6 mm, 14-pin DFN packages, and requires only
five external passive components. CCG2 is the secondgeneration product of the Cypress family of USB Power
®
®
Delivery and Type-C controllers with an ARM Cortex -M0
CPU. CCG2 includes a hardware implementation of the
USB Type-C transceiver and USB power delivery IP. In
addition, it has six Timer/Counter/Pulse Width Modulators
(TCPWMs), two serial communication blocks (SCBs), nine
GPIO pins, 32 KB of flash, and 4 KB of SRAM.
This application note explains various aspects related to
the design of a USB 3.1 EMCA Type-C cable using
EZ-PD CCG2.
1
Passive EMCA is an Electronically Marked Cable Assembly without a re-driver or electronics to condition the USB data signals.
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Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Introduction to USB Type-C Cables
USB has emerged as the preferred standard for connectors for data transfer and charging for PCs and smartphones. Standard
Type-A, Type-B and Micro-AB connectors shown in Figure 1 are the current USB-IF standards, but they have the following
limitations:




They use large connectors that prevent slim industrial designs (plug height: A = 4.5 mm; B = 10.4 mm).
They require a fixed-plug orientation and a fixed-cable direction.
They carry only USB signals and VBUS (= 5 V only).
Power delivery implementation is complicated, expensive, and limited to 7.5 W.
The USB Type-C specification is the new USB-IF standard that solves these problems and provides the following advantages:




Slim industrial design with a 2.4-mm plug height
Reversible plug orientation and cable direction
Transport of both USB signals and alternate mode signals, such as PCIe or DisplayPort signals, on the same connector
Easy implementation of low-cost power delivery up to 100 W
A USB Type-C receptacle, plug, and cable provide a smaller, thinner, and more robust alternative to the existing USB 3.1
interconnects (Standard and Micro USB cables and connectors). These are targeted for use in very thin platforms, ranging
from ultra-thin notebook PCs to smartphones in which existing Standard-A and Micro-AB receptacles are deemed too large,
difficult to use, or inadequately robust.
While the USB Type-C interconnect (with Type-C connectors at both ends) no longer physically differentiates plugs on a cable
by being an A-type or B-type (that is, the Type-C cable is reversible), the USB interface still maintains such a host-to-device
logical relationship. Determination of this host-to-device relationship is accomplished through a Configuration Channel (CC)
that is implemented within the cable. Using the CC, the USB Type-C interconnect defines a simplified 5-V VBUS-based power
delivery and charging solution that supplements what is already defined in the USB 3.1 specification. For more details, see
Type-C specification.
In addition, the CC is used for USB-PD (USB Power Delivery, discussed in the Introduction to PD section) communication to
set up and manage advanced power delivery features and Alternate/Accessory Modes. The USB-PD messages are delivered
across the dedicated Type-C CC using the Bi-Phase Marked Coding (BMC) method. For more details, see the USB PD
specification.
Figure 1. USB Type-C: Connector of the Future
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Type-C Receptacle/ Plug Interface
Figure 2 and Figure 3 show the USB Type-C Receptacle and Plug signals. Table 1 and Table 2 summarize the list of signals
used on the USB Type-C receptacle and plug.
Table 1. USB Type-C Receptacle Signals
Signal Group
Signal
Description
USB 3.1
TX1p, TX1n RX1p, RX1n
TX2p, TX2n RX2p,RX2n
The SuperSpeed USB serial data interface defines a differential transmit pair and a
differential receive pair.
On a USB Type-C receptacle, two sets of SuperSpeed USB signal pins are defined to
enable the plug-flipping feature.
USB 2.0
Dp1, Dn1
Dp2, Dn2
The USB 2.0 serial data interface defines a differential pair. On a USB Type-C
receptacle, two sets of USB 2.0 signal pins are defined to enable the plug-flipping
feature.
Configuration Channel
CC1, CC2
The CC channel in the receptacle detects the signal orientation and channel
configuration.
Auxiliary Signals
SBU1, SBU2
Sideband Use
VBUS
USB cable bus power
GND
USB cable return current path
Power
Table 2. USB Type-C Plug Signals
Signal Group
Signal
Description
USB 3.1
TX1p, TX1n RX1p, RX1n
TX2p, TX2n RX2p,RX2n
The SuperSpeed USB serial data interface defines a differential transmit pair and a
differential receive pair.
On a USB Type-C receptacle, two sets of SuperSpeed USB signal pins are defined to
enable the plug-flipping feature.
USB 2.0
Dp, Dn
The USB 2.0 serial data interface defines a differential pair. On a USB Type-C
receptacle, two set of USB 2.0 signal pins are defined to enable the plug-flipping
feature.
Configuration Channel
CC
The CC in the plug used for connection detect and interface configuration
Auxiliary Signals
SBU1, SBU2
Sideband Use
VBUS
USB cable bus power
VCONN
Type-C cable plug power
GND
USB cable return current path
Power
As shown in Figure 2, the receptacle signal functionally delivers both USB 3.1 (TX and RX pairs) and USB 2.0 (D+ and D−)
data buses, USB power (VBUS), ground (GND), Configuration Channel signals (CC1 and CC2), and two Sideband Use (SBU)
signal pins. The two sets of USB data-bus signal locations in this layout facilitate functionally mapping of the USB signals
independent of the plug orientation in the receptacle.
Figure 2. USB Type-C Receptacle Interface (Front View)
Figure 3 depicts the USB Type-C plug signals. Only one CC pin is connected through the cable to establish signal orientation;
the other CC pin is repurposed as VCONN for powering the electronics in the USB Type-C plug.
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Figure 3. USB Type-C Plug Interface (Front View)
A Type-C downstream-facing port (DFP) exposes Rp terminations on its CC pins (CC1 and CC2) while a Type-C upstreamfacing port (UFP) exposes Rd terminations on its CC pins, as shown in Figure 4. DFPs, specifically associated with the flow of
data in a USB connection, are typically the ports on a host, such as a PC or a hub, to which devices are connected. In its initial
state, the DFP sources VBUS and VCONN. On the other hand, UFPs are the ports on a device or a hub that connects to a
host. In its initial state, the UFP sinks VBUS.
Figure 4. Type-C Connection/ Orientation Detection
1
These cables expose Ra terminations on the VCONN pin, as shown in Figure 4. Rp and Rd terminations on CC pins detect the
connection event and identify the cable orientation. The DFP monitors both CC pins for a voltage lower than its unterminated
voltage to detect the connection event.
By being able to detect which of the CC pins (CC1 or CC2) at the Type-C receptacle is terminated by Rd at the UFP, the DFP
can determine one among the four possible cable orientations, as shown in Figure 5 and Table 3. The DFP can use this to
control the functional switch (MUX) for routing the SuperSpeed USB signal pairs appropriately irrespective of the cable
orientation.
Similarly, the UFP can control the functional switch to route its SuperSpeed USB signal pairs appropriately, as shown in Figure
6. After a connection and orientation is established, the DFP will repurpose CC1 or CC2 to provide cable power over the
VCONN pin of the plug. See Type-C Specification for more details on the Type-C connection and orientation detection
mechanism.
Figure 5. CC Pins Determine Plug Orientation
1
Image source: USB Type-C Specification
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Table 3. Cable Orientations
* For (1) and (2), see Figure 6.
Figure 6. Cable Flip/Twist
Cable
SSTX1
4 possible active
SS channel routes
1
SSRX1
1
SSRX1
USB
Host
Mux
SSTX1
SSTX2
SSRX2
2
1
1
2
2
SSTX2
4 possible
wiring maps
USB
Host
USB D+/ D-
USB D+/ D-
CC Logic,
VCONN Switch
Mux
SSRX2
2
CC1
1
1
CC1
CC2
2
2
CC2
CC Logic,
VCONN Switch
For USB 2.0, only one set of USB 2.0 signals (D+ and D-) is implemented in a USB Type-C cable. SBU signals are used in the
Alternate Mode supported by the Type-C specification, which enables multi-purposing of Type-C signals for alternate uses
such as DisplayPort. For example, in a DisplayPort application, USB 3.0 lines are used for video transmission and the SBU
lines for audio transmission. See Appendix A, which shows a possible application of alternate mode in an Accessory cable.
See Type-C Specification for more on Alternate modes.
Possible Type-C Cable Assemblies
The following USB Type-C cables are defined by Type-C specification:

USB Full-Featured Type-C cable, a USB Type-C to Type-C cable that supports USB 2.0 and USB 3.1 data operation. This
cable also includes SBU wires.


USB 2.0 Type-C cable with a USB 2.0 Type-C plug at both ends for USB 2.0 applications
Captive cable with either a USB Full-Featured Type-C plug or USB 2.0 Type-C plug at one end
Table 4 lists various Type-C standard cable assemblies in the perspective of electronic marking of cables.
Table 4. USB Type-C Standard Cable Assemblies
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Plug
1
Plug
2
USB
Version
Current
Rating
TypeC
TypeC
USB
2.0
3A
TypeC
TypeC
USB
3.1
3A
5A
5A
USB PD
(BMC)
Supported
Supported
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Electronic
Marking
Optional
Required
Required
Required
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
As listed in Table 4, all cables that are either full-featured or are rated at more than 3 A current need to be electronically
marked cables. Electronic marking is optional for USB 2.0 cables rated at 3 A, while it is needed for USB 3.1 cables rated at
3 A.
Various USB Type-C to USB legacy cable and adapter assemblies are also defined by the Type-C specification such as the
following:





USB 3.1/USB 2.0 Type-C (Type-C plug) to Legacy Host cable (Standard-A plug)
USB 3.1/USB 2.0 Type-C (Type-C plug) to Legacy Device cable (Standard-B plug)
USB 3.1/USB 2.0 Type-C (Type-C plug) to Legacy Micro/ Mini Device cable (Micro/ Mini-B plug)
USB 3.1 Type-C (Type-C plug) to Legacy Standard-A adapter (Standard-A receptacle)
USB 2.0 Type-C (Type-C plug) to Legacy Micro-B adapter (Micro-B receptacle)
See Type-C specification for more details.
USB Power Delivery
USB Power Delivery (PD) is a new USB standard that increases the power delivery over VBUS from 7.5 W to 100 W (with
voltage/ current as high as 20V/ 5A). With USB Power Delivery, the power direction is no longer fixed: Both hosts and devices
can act as either a Provider (a Type-C port that sources power over VBUS) or a Consumer (a Type-C port that sinks power
from VBUS) of power. For example, a monitor can be powered from the wall charger and, in turn, can power a notebook and a
hard disk drive, as shown in Figure 7.
Figure 7. USB-PD: One Power Adapter for the Desk
The USB PD specification provides more flexible power delivery with data over a single cable without the need for a device
driver. It has the potential to minimize waste as it becomes a standard for charging devices that are not satisfied by the Battery
charging specification, version 1.2. This standardization was driven as a means to increase charger reuse and, thus, reduce
electronic waste.
This specification, in addition to providing mechanisms to negotiate power, can be used for standard- and vendor-defined
messaging needed for custom cable applications. It also enables the discovery of cable capabilities such as supported speeds
and current levels.
USB PD Specifications, Revision 1.0, covered a power negotiation method over VBUS line of the USB bus (using BFSK
modulation over VBUS). USB PD Specifications, Revision 2.0, recommends the method of using power delivery protocol
messages over the CC.
The USB Power Delivery specification is guided by the following principles:
1.
2.
3.
4.
Works seamlessly with legacy USB devices
Compatible with existing compliant USB cables
Minimizes potential damage from non-compliant cables
Optimized for low-cost implementations
See the USB PD specification for more details.
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
SOP* Communication in USB PD
A Power Delivery communication starts with sequences of special symbols (called K-code marker) to delineate the start of a
packet. K-codes are special symbols provided by the 4b5b line-encoding scheme used in PD communication to delineate
packet boundaries.
In addition to encoding data, K-codes are used for special control functions, such as a hard reset and cable reset. The special
K-code sequence signifying a start of sequence is called “Start Of Packet” (SOP). Three sequences are defined: SOP, SOP’,
and SOP’’. SOP* is used to refer all the three SOP sequences. Figure 8 defines and differentiates SOP* packets:

SOP Packet: Any Power Delivery packet that starts with an SOP sequence. The communication between Port Partners
(DFP and UFP) uses SOP packets. These packets are not recognized by either Cable Plug.

SOP’ Packet: Any Power Delivery packet that starts with an SOP’ sequence used to communicate with a Cable Plug.
SOP’ packets are recognized by the electronics in the Cable Plug attached to the DFP (cable plug marked SOP’ in Figure
8) and are not recognized by the other Cable Plug or the port partner in UFP.

SOP’’ Packet: Any Power Delivery packet that starts with an SOP’’ sequence used to communicate with a Cable Plug
when SOP’ packets are being used to communicate with the other Cable Plug. SOP’’ packets are recognized only by the
electronics in the Cable Plug attached to the UFP (cable plug marked SOP” in Figure 8) and are not recognized by the
other Cable Plug attached to the DFP or the port partner in UFP.
Notes: The term “Cable Plug” in the SOP’/SOP’’ communication case is used to represent a logical entity in the cable that is
capable of PD communication. These entities may or may not be physically located in the plug.
Response to SOP” packets by the cable plug attached to UFP is optional, but the response to SOP’ packets by the cable plug
attached to DFP is mandatory in an EMCA.
Figure 8. SOP* Communication
Cable
Plug
(SOP’)
DFP
Electronically Marked Cable
Cable
Plug
(SOP”)
UFP
SOP’
Signalling
SOP”
Signalling
SOP
Signalling
SOP* communication takes place over a single wire (CC). This means that SOP* communication periods must be coordinated
to prevent important communication from being blocked. Communications between the Port Partners (SOP packets) take
precedence, implying that communications with the Cable Plug (SOP’/ SOP” packets) can be interrupted. See USB PD
specification for more details.
CCG2 Overview
EZ-PD CCG2 is a USB Type-C cable controller that complies with the latest USB Type-C and PD standards. Salient features
of CCG2 are:


Uses industry-standard 32-bit, 48-MHz ARM Cortex -M0 processor and 32 KB flash




Available in 20-ball, 1.63 mm × 2.03 mm WLCSP and 14-pin, 2.5 mm × 3.5 mm × 0.6 mm DFN packages
2
®
®
2
Integrates a single Type-C Transceiver, termination resistors (RP, RD, and RA shown in Figure 4) and system-level ESD
(8-kV contact, 15-kV air)
Provides a complete one-chip hardware and firmware solution for a USB Type-C EMCA
Capable of operating from three power sources: VCONN1, VCONN2, and VDDD
Two independent VCONN rails with integrated isolation between the two
See Type-C Specification for more details on termination resistors.
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
CCG2 provides a complete USB Type-C and USB Power Delivery port control solution for passive cables, active cables, and
powered accessories. Table 5 shows the available CCG2 parts for various applications.
TM
Table 5. EZ-PD
CCG2 Product options
Features
CYPD2103
CYPD2104
CYPD2105
Application
Passive Cable
Accessory3
Active Cable4
Package
20-ball WLCSP, 14-pin DFN
20-ball WLCSP
20-ball WLCSP
3
An upstream-facing port (UFP) with the form factor of a cable or dongle.
4
Electronically Marked Cable Assembly with a re-driver to condition USB data signals.
See CCG2 datasheet for more details.
EMCA Applications
All USB full-featured Type-C cables are electronically marked. Such cables incorporate electronics that require VCONN as the
cable power. This provides a method to determine the characteristics of the cable, such as its current-carrying capability,
performance, and vendor identification (USB Type-C Cable ID function).
Characteristics of the cable include:



Product type, such as Passive cable, Active cable, and Alternate mode adapter



Cable latency: indicates the latency of cables

USB SuperSpeed signaling support: indicating the speed supported by the USB data signals in the cable (USB 2.0 or
USB 3.1, Gen 1 and Gen 2)
Cable hardware and firmware version assigned by the vendor
The other end of Type-C cable: indicating if the cable is a Type-C to Type-C or a Type-C to legacy cable or a Type-C to
receptacle, and so on
Current-handling capability (1.5 A, 3 A or 5 A)
SOP” controller present or not: indicating if the cable is enabled for SOP” response by the electronics at the UFP end of
the cable
See the USB PD specification.
An EMCA can be any one of the following types:


Passive EMCA: An EMCA that does not modify the USB data signals

Accessory: A UFP with the form factor of a cable or dongle
Active EMCA: An EMCA with additional electronics to condition the USB data signals, such as drivers, to allow for
implementing longer cables
EMCA cables can be implemented with or without the VCONN wire extending through the cable. EMCA cables with the
VCONN wire extending through the cable (Refer section Passive EMCA with One CCG2 per Cable for more details) need
isolation elements. These isolation elements prevent VCONN from traversing end-to-end through the cable. In EMCA cables in
which the VCONN wire does not extend through the cable (Refer section Passive EMCA with One CCG2 per Cable Plug (Two
Chips per Cable) - SOP’ Response Only for more details), an SOP’ element is required at each end of the cable. In this case,
no isolation elements are needed.
Some of the key application-level requirements for EMCA applications are as follows:




Support USB-PD protocol as defined in the PD 2.0 specification
Support SOP’ and SOP” as defined in the PD 2.0 specification
Support an integrated Ra resistor on the VCONN
The ability to power the chip from VCONN
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2





Integrated isolation between the two VCONN pins (VCONN1 and VCONN2)
Ability to disconnect the Ra resistor to conserve power
Integrated system-level ESD protection on CC and VCONN pins
Integrated bootloader to support a firmware update over CC
Cable authentication using a secure external EEPROM
CCG2 in Passive EMCA Applications
EZ-PD CCG2 is targeted at electronically marked cable assemblies. This section describes two representative applications of
CCG2 in passive EMCAs. (Additional applications are described in the Appendix). In each application, CCG2 and associated
circuits are assembled into one or both ends of a cable called the “plug” (see Figure 9). Inside each plug housing or mold, the
chips are assembled on PCBs called “paddle boards.” Each EMCA includes at least one plug with a CCG2, which responds to
identification commands from the USB Host over the CC.
Figure 9. USB Type-C Plug Housing
The two examples in this section show the application of CCG2 in passive EMCAs. Before discussing CCG2 in passive EMCA
applications, the CCG2 power subsystem is discussed to promote a better understanding of the VCONN signal handling.
CCG2 Power Subsystem
CCG2 can operate from one of the three power sources: VCONN1, VCONN2, or VDDD.
VCONN1 and VCONN2 pins can be used as connections to the VCONN pins in a USB Type-C cable system. Each of these
inputs supports operation from 4.0 V to 5.5 V. An internal isolation between VCONN1 and VCONN2 pins is provided, allowing
them to be at different levels simultaneously, as shown in Figure 10. These internal diodes act as the isolation elements
needed to implement an EMCA solution with the VCONN wire extending through the cable.
CCG2 can also operate from 2.7 V to 5.5 V when operated from the VDDD supply pin. In this mode of operation, VCONN1
and VCONN2 must not be connected in the system. In applications in which the VCONN pins are used as supply sources, the
VDDD pin can be used as an output voltage.
The internal GPIO buffers of CCG2 are powered from VDDIO rail. Typically, this rail will be shorted to VDDD in cable
applications.
For more details on Power subsystem, see the CCG2 datasheet.
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Figure 10. CCG2 Power and Bypass Scheme
4.0 V to 5.5 V VCONN1
0.1uF
VCONN2
RA
RA
VDDD
1uF
Core Regulator
VCCD
VDDIO
1uF
GPIO
CC
Tx/Rx
Core
VSS
Passive EMCA with One CCG2 per Cable
This EMCA solution contains a CCG2 chip in only one of its plugs. This solution requires the single VCONN wire to run
through the cable, so that the chip can be powered irrespective of which plug is connected to the host (DFP).
Figure 11. Passive EMCA Solution with One CCG2 per Cable
Passive EMCA With One CCG2 Per Cable
VBUS
2
12
CC
VCONN Far
VCONN Near
CCG2
CYPD2103
GND
Type-C Plug
Type-C Plug
Data Lines (USB SuperSpeed, USB Hi-Speed, PCIe, DisplayPort)
2
Passive EMCA with CCG2
A lower-cost implementation of
EMCA that supports the PD
protocol. A CCG2 is embedded
at only one end of the cable and
is powered by either USB TypeC port
In this case, the CCG2 will respond only to SOP’ packets. After the cable is enumerated, the host may shut down the VCONN
supply. One of the key and unique requirements for this application is the ability to power the chip from two separate VCONN
pins.
Pros:
This solution needs only one CCG2 chip at one of the cable ends.
Cons:
This solution increases the wire cost (needed for the VCONN signal to run through the cable).
Figure 11 shows the block diagram for the Passive EMCA solution with one CCG2 per cable, while Figure 12 shows the
schematic. As shown in Figure 12, VCONN from one end of the cable is to be connected to VCONN1 of the CCG2; VCONN
from the other end of the cable is to be connected to VCONN2 of CCG2.
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
For the single-chip solution, GPIO (ball D3 of the WLCSP package/pin 13 of the DFN package) must be left floating to disable
the SOP” response. When this GPIO is left floating, the CYPD2103 is configured to always respond to SOP’ packets only. The
response to SOP’/ SOP” packets is not dynamically determined based on the connection to UFP or DFP.
This will be used in the case of a one-chip solution (cable with one CCG2 chip for the whole cable) in which the chip may get
powered either from VCONN1 or VCONN2, based on the cable orientation. Irrespective of the end of the cable, CCG2 will
always respond to SOP’ packets only irrespective of whether it is powered from VCONN1 or VCONN2.
Figure 12. CCG2 Single-Chip EMCA Schematic
Type-C
Plug
Type-C
Plug
VBUS
VCONN 2
VCONN 1
1uF
E4
E3
E1
VDDD
VDDIO
VCONN1
VCONN2
0.1uF
GPIO
C3
A1
VDDIO
4.7 k
GPIO
GPIO
GPIO
VCCD
1uF
CYPD2103-20FNXIT
B1
GPIO
CC2
XRES
C4
D3
0.1uF
C2
D2
B2
A4
CC1 B4
D4 VSS
C1 VSS
RD1
I2C_0 I2C_0
_SCL _SDA
A2
A3
B3
SWD_ SWD_
IO
CLK
D1
E2
CC
SuperSpeed and HighSpeed Lines
GND
Notes:
Figure 12 is for representative purposes only and is based on a WLCSP package. For DFN reference, see Appendix.
www.cypress.com
Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Passive EMCA with One CCG2 per Cable Plug (Two Chips per Cable) - SOP’ Response Only
This EMCA solution contains two CCG2 chips – one in each plug. In this solution, the VCONN signal does not run through the
cable, but stops at the CCG2 device in each plug. In this case, only one CCG2 is powered at a time, depending on which is
nearer to the DFP that supplies VCONN. The powered CCG2 responds to SOP’ packets only. After the cable is enumerated,
the host may shut down the VCONN supply.
Pros:
This solution saves wire cost (needed for VCONN signal if it runs across the device).
Cons:
This solution needs two CCG2 chips, one at each cable end.
Figure 13. Passive EMCA Solution with One CCG2 per Cable Plug
Passive EMCA With One CCG2 Per Cable Plug
VBUS
2
12
CC
VCONN
VCONN
CCG2
CYPD2103
GND
CCG2
CYPD2103
Type-C Plug
Type-C Plug
Data Lines (USB SuperSpeed, USB Hi-Speed, PCIe, DisplayPort)
2
Passive EMCA with CCG2
An EMCA that supports the PD
protocol. A CCG2 is embedded
at each end of the cable and is
powered individually by the USB
Type-C port at each end.
Figure 13 depicts the block diagram and Figure 14 shows the schematic for the Passive EMCA solution with two CCG2 chips
per cable, with one getting powered. As shown in Figure 14, VCONN from either end of the cable is connected to VCONN1 of
CCG2 at the respective end. GPIO (ball D3 of the WLCSP package/ pin 13 of the DFN package) can be left floating or pulled
LOW.
Whichever way the cable gets connected, one CCG2 always gets powered through VCONN1, and it will respond to SOP’
packets only.
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Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Figure 14. CCG2 Two-Chip EMCA Schematic (One Chip Powered)
Type-C
Plug
Type-C
Plug
VBUS
VCONN2
VCONN1
1uF
1uF
E4
E3
E1
VDDD
VDDIO
VCONN2
VCONN1
0.1uF
GPIO
C3
A1
VDDIO
4.7 k
GPIO
GPIO
VCCD
GPIO
1uF
CYPD2103-20FNXIT
B1
GPIO
CC2
XRES
D4 VSS
C1 VSS
I2C_0 I2C_0
_SCL _SDA
A2
A3
E4
C4
E1
VDDIO
VCONN1
GPIO
D3
C3
C2
A1
D2
VDDIO
B2
GPIO
VCCD
GPIO
1uF
4.7 k
A4
GPIO
CYPD2103-20FNXIT
B1
D4 VSS
B3
C1 VSS
I2C_0 I2C_0
_SCL _SDA
A2
A3
SWD_ SWD_
IO
CLK
D1
E2
GPIO
CC2
XRES
CC1 B4
RD1
E3
VDDD
VCONN2
C4
D3
0.1uF
C2
D2
B2
A4
CC1 B4
RD1
B3
SWD_ SWD_
IO
CLK
D1
E2
CC
SuperSpeed and HighSpeed Lines
GND
Notes:
Figure 14 is for representative purposes only and is based on WLCSP package. For DFN reference, see Appendix.
Design Guidelines
Hardware Guidelines
Figure 12 and Figure 14 show the hardware schematics for the one-chip and two-chip solutions of EMCA using CCG2. As
shown in Figure 12, CCG2 can be a one-chip USB Type-C cable solution with an integrated Type-C transceiver, termination
resistors and system-level ESD-protection circuits. This solution requires only four external decoupling capacitors* and a
resistor to operate.
It is recommended to have provisions for probes or jumpers on SWD lines to help facilitate debug and programming at the
paddle-card level. CCG2 also allows the firmware of the assembled cable to be upgraded over the CC line through the built-in
bootloader.
TM
See AN95599 – Hardware Design Guidelines for EZ-PD
CCG2 for more details on hardware design.
Notes:
* In addition, four capacitors are needed on VBUS pins of Type-C connector (10-nF bypass capacitor per VBUS pin on the
Type-C connector), according to the Type-C Specification. See Type-C Specification for more details.
Firmware Upgrade Guidelines
EZ-PD CCG2 is available in three pre-programmed versions to suit various design needs, as listed in Table 5. A vendorspecific cable application will need the vendor command implementation that determines the product capabilities and
functionality. Contact Cypress for details about the firmware and a custom application.
The CCG2 firmware has the following basic capabilities:
1.
The firmware detects the cable plug location – whether it is attached to the host port (downstream port) or the device port
(upstream port).
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Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
2.
The firmware responds to all structured VDMs (Vendor Defined Messages) with SOP’ (if the cable plug-end is near to the
host-end) and SOP’’ (if the plug-end is near to the device-end).
3.
The firmware responds to all Cypress-defined unstructured VDMs with SOP (for accessory mode application), SOP’ (if the
cable plug-end is near to the host-end) and SOP’’ (if the plug-end is near to the device-end). These messages are used
for firmware upgrades.
4.
The firmware responds to a set of unstructured VDMs as reference. The VDM handlers must indicate the functionality by
toggling a set of GPIOs.
5.
The firmware includes a bootloader that is capable of upgrading the PD firmware on the device. The bootloader receives a
firmware image over Cypress-defined unstructured VDMs.
6.
The device stays in Deep-Sleep mode when the CC lines are in the Idle state and wakes up to respond to PD messages.
It returns to the Deep-Sleep mode as soon as the PD bus is detected as idle.
7.
The bootloader supports two copies of firmware (for CYPD2103 and CYPD2105). It verifies the validity of the firmware
image based on the checksum before passing control to the firmware.
8.
The SOP/ SOP” response is determined based on a GPIO (ball D3 of the WLCSP package/ pin 13 of the DFN package)
status provided as an input to the CCG2 device along with VCONN1/ VCONN2 signals, as shown in Table 6.
Table 6. SOP Response from the CCG2 Controller
VCONN_1
VCONN_2
GPIO***
SOP'
SOP"
x**
x
Floating


4V – 5.5V
x
Pulled LOW


<4V
x
Pulled LOW


** x in Table 6 indicates Don’t care
*** GPIO is ball D3 of the WLCSP package/pin 13 of the DFN package
CCG2 can be upgraded to keep pace with USB-IF specification changes. Contact Cypress for firmware upgrades. The on-chip
32-KB flash can be programmed using the SWD interface or over the Type-C Configuration Channel (CC signal).
U p g r a d e C C G 2 o ve r S W D U s i n g M i n i P r o g 3
®
A firmware upgrade using the SWD interface can be done using a PC running PSoC Programmer™ software and a
MiniProg3 programmer. This method of programming can be used on a paddle card equipped with the SWD pins or header
and is typically used during product development.
For more details on the steps, see the knowledge base article Programming EZ-PD™ CCG2 Using PSoC® Programmer and
MiniProg3.
Figure 15. Upgrade over SWD (Using MiniProg3)
www.cypress.com
Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Upgrading CCG2 Firmware Over CC
A PC running a firmware upgrade application, cc_flash.exe, available at this webpage, can be used to program CCG2 in the
USB Type-C cable directly over the CC line with the help of a CCG1 host demo board. This method can be deployed by cable
manufacturers to provide upgrades to the end user or to program the firmware after the cable assembly is manufactured.
CCG2 is factory-programmed with a bootloader to be first-time programmable in the field through the Type-C interface.
Figure 16. Upgrade Using CC
2
The USB-Serial Bridge in the CCG1 host demo board acts as an USB-I C Master bridge. The USB-Serial bridge
2
communicates with the CCG1 Type-C Host Controller’s I C slave interface. CCG1 is a USB Type-C port controller with PD that
complies with the latest USB Type-C and PD standards, which provides a complete solution to add USB Type-C and PD
support to power adapters, notebooks, tablets, monitors, and EMCA with up to 100 W of power delivery. For more details on
CCG1, see the CCG1 webpage.
2
The Cypress-provided configuration utility, cc_flash.exe, sends I C commands to CCG1 Type-C Host Controller via a USBSerial Bridge.
The CCG1 Type-C host controller is configured to communicate with the EMCA over the Type-C Interface. The CCG1
2
firmware detects the presence of an EMCA and applies VCONN. It tunnels I C commands received via the USB-Serial Bridge
to the EMCA in the form of structured and unstructured VDMs.
For more details on the steps, see the knowledge base article Upgrading the Firmware of EZ-PD™ CCG2 Devices Over CC.
Summary
This application note discussed various aspects related to the design of passive USB 3.1 Type-C cable using CCG2.
Customers can bring cost-optimized Type-C-compliant EMCAs to market faster with CCG2, an ARM Cortex-M0-based cable
controller with 32 KB flash, requiring minimal external passive components or analog circuits.
www.cypress.com
Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Appendix A: Other CCG2 Applications
This section discusses possible CCG2 applications besides passive EMCA cables. Key application requirements are the same
as those listed in the EMCA applications section.
Active EMCA Solution with One CCG2 per Cable – SOP’ Response Only
The main function of an active EMCA is to provide signal conditioning by adding a re-driver on the data path. Active cables
that require configuration/signal conditioning (referred to as managed active cables) use USB Power Delivery Structured
vendor defined messages (VDMs –SOP’ packets) to discover and configure the cable. Some managed active cables only
have a single USB PD controller in the cable that responds to USB PD Structured VDMs (SOP’ packets only).
A Type-C active EMCA solution requires a CCG2 for electronic marking in addition to the signal-conditioning device (Re-driver
in Figure 17). This solution draws power from the VCONN input to the cable. Such a cable advertises itself as an active cable
by placing the Ra resistor on the VCONN line and an Rd resistor on the CC line. Unlike a passive EMCA, the host providing the
power on VCONN does not shut down power.
Figure 17. Active EMCA Solution with One CCG2 per Cable
Active EMCA
VBUS
2
CCG2
CYPD210520FNXI
2
Type-C Cable
Type-C Plug
Data Lines (USB SuperSpeed, USB Hi-Speed, PCIe, DisplayPort)
12
12
Re-driver
GPIOs
VCONN Near
VCONN Far
CC
GND
2
Active EMCA with CCG2
An EMCA that includes an
embedded re-driver to extend
the cable length.
Contact Cypress for the firmware solution for this application.
www.cypress.com
Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Managed Active EMCA Solution with One CCG2 per Cable Plug - SOP’ and SOP” Responses
When a managed active cable requires independent management or signal conditioning at each end of the cable, separate
USB PD controllers responding to USB PD structured VDMs (SOP’ and SOP” packets) must be located in each plug.
Figure 18. Managed Active Cable with One CCG2 per Cable Plug
Managed Active EMCA
2
VBUS
Data Lines (USB SuperSpeed, USB Hi-Speed, PCIe, DisplayPort)
Type-C Plug
12
Re-driver
Re-driver
2
CCG2
CYPD2105
GPIOsV
CONN1
CCG2
CYPD2105
VCONN2 VDDD
VDDD VCONN2
VCONN
VCONN1
2
GPIOs
Type-C Plug
12
12
VCONN
CC
2
GND
This active cable solution contains two CCG2 chips – one on each plug. VCONN is wired across the cable (but not straight
through to the other end of the plug). In this solution, the wiring is done such that the cable is reversible. The host providing
power on VCONN does not shut down power.
The VCONN signal of the cable plug at each end is connected to the VCONN1 input of the corresponding CCG2; another
single conductor through the cable connects VCONN2 and VDDD pins of the CCG2 chip at both ends. When CCG2 is
powered from any of the VCONN pins, VDDD acts as output voltage. In this case, both CCG2 chips will get powered: one
through VCONN1 and the other through VCONN2. The internal firmware uses the GPIO (ball D3 of the WLCSP package/pin
13 of the DFN package) as a strap option to determine whether to respond to SOP”. SOP” response is enabled by strapping
this GPIO to ground on the paddle card.
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Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Regardless of which end of the cable is connected to the DFP, CCG2 chips of both ends are powered. CCG2 has detectors on
both VCONN1 and VCONN2 that indicate to the firmware inside CCG2 as to which input is supplying power. The CCG2 with
its VCONN1 powered is considered for SOP’ response. CCG2 responds to SOP”, if it is enabled for SOP” response by pulling
GPIO (ball D3 of the WLCSP package/pin 13 of the DFN package) LOW and it is powered through VCONN2.
Figure 18 depicts the block diagram for the managed active cable with two CCG2 chips per cable, with both of them getting
powered.
Accessory Solution
An accessory solution will require one CCG2 to implement USB Type-C and USB-PD protocols. A common form of an
accessory is a converter dongle shown in this example. An example is a USB Type-C Thunderbolt adapter. Such an adapter
will have a USB Type-C plug on one end and a set of PCIe and DisplayPort ports on the other. An accessory will also require
an alternate-mode implementation. An accessory can be implemented as a standard UFP device capable of operating from
VBUS and generating its own VCONN or a powered accessory operating from VCONN. Figure 19 shows one application of an
accessory.
Figure 19. Accessory Solution
USB Type-C HDMI Dongle
USB HiSpeed
Secure
EEPROM
2
2
CCG2
I2C CYPD2104-20FNXI GPIOs
2
2
USB
Device
I2C
Controller
DisplayPort 8
to HMDI4
Bridge HDMI
VCONN
HDMI Plug
Type-C Plug
Data Lines (USB SuperSpeed, USB Hi-Speed, DisplayPort3)
12
10
CC
2
GND
USB Type-C HDMI Dongle
A notebook PC accessory that
converts a USB Type-C port to
an HDMI output to connect a
monitor.
The key application-level requirements needed for this application are:



Support integrated Rd resistors on CC pins per Type-C specification
Ability to power from VBUS
Support detection of current limit
Contact Cypress for the firmware solution for this application.
www.cypress.com
Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Appendix B: Reference Schematics
CYPD2103-14LHXIT Single-Chip EMCA Schematic
Type-C
Plug
Type-C
Plug
VBUS
VCONN 2
VCONN 1
1uF
7
5
VDDD
VCONN2
VCONN1
0.1uF
GPIO
GPIO
6
VDDIO
4.7 k
GPIO
VCCD
1uF
4
10
0.1uF
11
13
CYPD2103-14LHXIT
12
2
XRES
CC1 3
VSS
I2C_0
_SCL
1
I2C_0
_SDA
14
SWD_ SWD_
IO
CLK
9
8
CC
SuperSpeed and HighSpeed Lines
GND
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Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
CYPD2103-14LHXIT Dual-Chip EMCA Schematic
Type-C
Plug
Type-C
Plug
VBUS
VCONN2
VCONN1
1uF
1uF
7
7
5
VDDD
VCONN2
VCONN1
0.1uF
GPIO
GPIO
6
VDDIO
4.7 k
GPIO
VCCD
1uF
5
4
XRES
10
GPIO
GPIO
6
13
VDDIO
4.7 k
GPIO
I2C_0
_SDA
14
12
XRES
0.1uF
11
13
CC1 3
VSS
I2C_0
_SCL
1
SWD_ SWD_
IO
CLK
9
8
4
10
CYPD2103-14LHXIT
CC1 3
VSS
I2C_0
_SCL
1
VCCD
1uF
2
2
VCONN1
11
CYPD2103-14LHXIT
12
VDDD
VCONN2
I2C_0
_SDA
14
SWD_ SWD_
IO
CLK
9
8
CC
SuperSpeed and HighSpeed Lines
GND
www.cypress.com
Document No. 001-95615 Rev. *A
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Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Document History
Document Title: AN95615 - Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
Document Number: 001-95615
Revision
ECN
Orig. of
Change
Submission
Date
Description of Change
**
4710707
GAYA
04/03/2015
New Application Note
*A
4723949
GAYA
04/21/2015
Updated part numbers
Updated links to Type-C Specifications
www.cypress.com
Document No. 001-95615 Rev. *A
21
Designing USB 3.1 Type-C Cables Using EZ-PD™ CCG2
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© Cypress Semiconductor Corporation, 2015. The information contained herein is subject to change without notice. Cypress Semiconductor
Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in a Cypress product. Nor does it convey or imply any
license under patent or other rights. Cypress products are not warranted nor intended to be used for medical, life support, life saving, critical control or
safety applications, unless pursuant to an express written agreement with Cypress. Furthermore, Cypress does not authorize its products for use as
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Disclaimer: CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress reserves the
right to make changes without further notice to the materials described herein. Cypress does not assume any liability arising out of the application or
use of any product or circuit described herein. Cypress does not authorize its products for use as critical components in life-support systems where a
malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress’ product in a life-support systems
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Use may be limited by and subject to the applicable Cypress software license agreement.
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Document No. 001-95615 Rev. *A
22
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