A USB connector will have 4 basic signals called as VBUS, D+, D- and GND.
VBUS will be +5V w.r.t. the GND(Ground) signal.
D+ and D- are used for data communication between Host and Device.
For example when we connect a pen drive to the USB Port of a Host PC, the circuitry on the pen drive is powered using the VBUS and GND signals.
Then the data exchange happens over D+ and D- to see the files stored on the Pen Drive.
Now, when it comes to charging, USB is keep evolving w.r.t Data throughput and power supply.
For example these are some of the Specs from USB committee, USB 1.1, USB2.0, USB3.1, USB3.2 and USB4.
When a device is USB1.1 capable then it supports 5V@100mA.
A USB 2.0 device can support 5V@500mA. USB3.x device can support upto 5V@900mA. USB4 uses a special connector called as Type-C connector which is capable of providing upto 5V@3A
The others are 5V@1.5A and 5V@2.1A. These are called as either (CDP or DCP). When we refer CDP it means the device can charge and enumerate. When we say DCP the device can be only charged on that port and no enumeration of the device is allowed.
No comments:
Post a Comment