FAQs about USB Type-C/PD
Explain what exactly is meant by a few meters over how many Gs of HF line, thanks!
▪ Performance indicators of wire transmission
Low frequency: below 12KHz, the main parameters are capacitance, characteristic capacitance unbalance
High frequency: above 12KHz, parameters are attenuation, crosstalk, delay, delay difference, characteristic impedance, transmission speed, etc..
Common high frequency related units and conversion dB decibels, mainly to describe the sound class units, attenuation and crosstalk Hz Hz, the unit of frequency Ω Ohm, the unit of impedance Ps, ns, picoseconds, nanoseconds, the unit of time Unit conversion: (thousands of decimal) T Tai (1012) G Gee (109) M Mega (106) K thousand (103) ★ International units m milli (10-3) μ micro (10-6) n nano (10-9) p phi (10-12) f fly (10-15)
▪ High-frequency line over a few meters over how many G, mainly refers to, in accordance with the test specifications, and the actual test wire test data for comparison, in line with the test specifications inside the parameters, that is, through, does not meet the requirements of the test specifications, that is, not through! (The following bit of data for example)
What is the limit of the existing twisted pair cable or coaxial cable to meet the USB 3.1 Gen1 (5G), respectively?
▪ The following diagram is a reference of the cable structure of USB3.1 twisted pair cable and coaxial cable respectively!
▪ The following chart shows the length reference of TYPE-C series respectively!
What is the difference between USB Power Delivery (USB PD) and USB Type-C?
▪ USB Power Delivery (USB PD) is a protocol specification that supports up to 100W of power delivery and data communication in a single cable.
▪ USBType-C is a new non-directional forward/reverse USB connector specification that supports a wide range of new standards, including USB 3.1 (Gen1 and Gen 2), Display Port, HDMI, and USB PD.
USB Type-C ports can support up to 5V3A power transmission by default, and up to 100W power transmission if USB PD is implemented in the USB Type-C port.
Therefore, having a USB Type-C port does not mean that it supports USB PD.
☞ Is the USBType-C connector mandatory for USB 3.1 Gen 1 or Gen 2 specification and is USBType-C equivalent to USB3.0/3.1?
▪ Currently, we can use traditional Type-A or Type-B connectors to support the Gen 1 and Gen 2 specifications, USB Type-C specification is a new interface certification specification published by the USB Developer’s Forum (USB-IF) that supports up to 100W power transfer and non-directional forward and reverse plugging. All USB 3.1 Gen 1 or Gen 2 products can use the USB Type-C interface.
So our answer is that the USB Type-C specification and the USB 3.1 Gen1 or Gen 2 specification are independent of each other.
☞ What are DFP, DRP and UFP?
■ DFP (DownstreamFacing Port) is a USB Type-C type port installed on a host or hub and connected to a device ■ UFP (Upstream Facing Port) is a device or hub connected to a host or hub.
USB Type-C type port connected to DFP.
■DRP (Dual Role Port, Dual Purpose Power Role is a definition that can be used as a Source or Sink role in USB Type-C type ports.
For example, the USB Type-C port on a laptop supports DRP (i.e. Type-C Dual Role Power Port), which can be used as both a Power Source (when connecting a removable disk or cell phones) and as a Sink (when connecting to a display or power adapter).
☞ What is the Configuration Channel (CC) line and what is the maximum speed of the CC bus?
The ■CC bus is the data line used for USB-PD communication between the port and the EMCA.
■ The USB Type-C socket has two pins CC1 and CC2, one of which is identified as the CC line based on the direction of the plug for USB Type-C connections.
For USB Type-C plugs, the CC cable is fixed.
The CC line can run the following functions:
Detects USB Type-C plug orientation to establish USB data bus routing
Detects USB port connections from DFP to UFP
Establish the roles of DFP and UFP between ports
Find and configure VBUS
Configuring VCONN
Find and configure optional standby and accessory modes
The bit rate of the CC line ranges from 270 Kbps to 300 Kbps and is rated at 300 Kbps.
☞ What is the difference between Cypress USB-PD2.0 and Qualcomm QC fast charging?
■USB-PD 2.0 is a protocol developed by the USB-IF that provides a power supply mechanism between USB devices with up to 100 W (20V, 5A) and the ability to support both USB and non-USB data signals on the USB Type-C port, which allows flexible negotiation of power direction between host and peripheral devices.
Quick Charge 2.0 can transfer up to 60 W of power, but unlike USB-PD, Quick Charge 2.0 cannot support both power Unlike USB-PD, Quick Charge 2.0 does not support both power and data transfer, nor does it support flexible power direction selection during charging.
☞ What is the maximum number of Power Delivery Objects (PDO) that the Cypress USB-PD controller can support? What are the supported power profiles?
The Cypress USB-PD supports up to 7 PDO’s for pull and fill current applications.
▪ The USB-PD specification does not require which power profiles the application device needs to support. Pull-current and fill-current PDO’s depend on the application design. section A.1 of the USB Type-C specification defines standardized combinations of voltage and different current ranges. it is important to note that the power profiles defined in section A.1 are only recommended power profiles and are not mandatory, but at least one is required that can be used to support a 5V pull-current PDO.
☞ Can I use only the USB and standard 5 V VBUS functions of the USBType-C port?
Yes, you can use a USB Type-C port that is USB-only and supports standard 5-V VBUS.
Host side: The default port currents provided by the host Type-C port for USB 2.0 (500mA) and USB 3.0 (900mA) are 5V 3A and 5V 1.5A, respectively. USB Type-C hosts indicate the current capacity by stringing an appropriate pull-up resistor Rp on the CC lines (CC1 and CC2).
Device side: Only USBType-C devices are supported and require a 5.1K pull-down resistor Rd to be connected in series on the CC cable. if the device is equipped with a USB Type-C plug, Rd needs to be connected in series on both CC1 and CC2 cables. however, if the device is equipped with a Type-C plug, Rd only needs to be connected on the CC cable.
☞ How do USBType-C devices handle VBUS voltages greater than 5V?
When a device requires a supply voltage greater than 5V, it requires the ability to communicate with USB-PD, which pulls current to send the power profile to the device, which then requests one of the installed power profiles based on its supply current capacity, and establishes a protocol that allows the host to provide the requested voltage on VBUS.
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