What is an E-mark chip? and must the USB 3.1 cable have an E-mark chip?

   E-mark (Electrically Marked Cable),The USB Type-C active cable is packaged with an E-Marker chip, DFP and UFP use the PD protocol to identify the properties of the cable: power transmission capability, data transmission capability, ID, etc.
   CC(Configuration Channel):Configuration channel, this is the key channel added in USB Type-C, identification of positive and negative plug, data between USB devices, connection and management of VBUS, etc.
   USB PD(USB Power Delivery): PD is a communication protocol, which is a new way of connecting power and communication. It allows USB devices to transfer up to 100W (20V/5A) of power, while it can change the port's properties, It is also possible to switch the port between DFP and UFP, and communicate with the cable to obtain the properties of the cable.
   All full-featured Type-C cables should be packaged with E-Marker, but USB 2.0 Type-C cables do not require E-Marker.

   First rule of necessity for E-mark: If your device voltage is 5V and the current does not exceed 3A. It depends on the power supply and data transmission characteristics of the device itself. If the device itself only supplies power to the outside, or only accepts the other party's power supply, and the power supply role and the data transmission role are the default match (that is, the power supply is HOST, and the power is Slave or device). ), then you don't need a TYPE-C chip

   Second rule of necessity for E-mark: If you want to provide more than 5V through the USB TYPE-C interface, or more than 3A, then you need the TYPE-C interface chip to implement the USB PD protocol.

   Third rule of necessity for E-mark: Does the C to C USB cable require an E-mark chip? The criterion is whether the current will exceed 3A? If not, the E-mark chip not be needed. For the A to C, B to C cable, it depends on whether the Battery Charging protocol needs to be implemented. If yes, the LDR6013 can be used. The advantage is that it can realize charging and data transmission, avoiding some adapters that follow the Battery Charging protocol cannot charge Apple devices