The difference between OTG data cable and ordinary USB data cable!

The USB data cable has become a common and essential digital accessory in daily life. However, with the rapid development of the mobile phone industry, the OTG cable has gradually entered the public's field of vision. The OTG cable is so similar to the USB cable, so what is the difference between them?

 

The USB data cable is used to connect the mobile phone and the computer. It can access the data such as photos and music in the mobile phone through the computer. At the same time, because the mobile phone has its own memory or expansion card, in a sense, the mobile phone is also another kind of U disk. Of course, it is also an indispensable connection bridge for charging mobile phones, tablets, MP4 and other digital devices.

 

So, what does the OTG data cable do? Simply put, with the OTG data cable, your mobile phone does not need to go through a PC or notebook. It can be directly connected to USB devices such as USB flash drives, mice, and keyboards through the OTG data cable. That is to say, the mobile phone can directly connect to the USB flash drive to find information, Connect the mouse to play games, connect to the keyboard to type quickly, and connect to the camera to view pictures. In other words, the OTG line eliminates the need for each device to pass through a computer to exchange information. It not only expands the functions of mobile phones, but also allows us to connect to the Internet more conveniently, and is more suitable for the development of this mobile Internet era. Tablets and other digital devices with OTG functions are also applicable. Of course, the premise is that your digital device must support OTG function!

 

The difference between the OTG cable and the ordinary USB cable is that when the USB data cable is connected to the computer, the external device is powered by the computer, and when the OTG data cable is connected to the U disk and other devices, the main object such as the mobile phone must supply power to the U disk and other peripherals.

 

So how does the mobile phone recognize the USB data cable and the OTG data cable? After disassembling the two wires, you will find that the 4th pin of the USB data cable is floating, and the 4th pin of the OTG data cable is shorted to ground. The mobile phone chip should judge whether the inserted OTG data cable or USB data is inserted through the 4th pin. Line, and use this to decide whether to turn on the OTG power supply function.

 

The difference in hardware is that there is a PIN at one end of the OTG cable connected to a GND ground wire, so that the machine can distinguish who is the host and who is the peripheral of the Device. The appearance alone cannot distinguish between the OTG cable and the ordinary USB cable.

 

The pins at the traditional usb interface are: 1. vbus (5v) 2. GND3. D+4. The DOTG line only has a Micro interface, and a total of 5pins are 1. vbus2. GND3. D+4. D-5. ID

 

There are 4 lines running inside the USB cable, the difference is the connector. Mobile phones/tablets use Micro USB connectors, connect to ordinary USB cables, and the ID pin is floating, so it operates in client/peripheral mode. If ID GND is grounded, it will enter host mode.