USB-C 3.1 with E-Mark

E-Mark is short for Electronically Marked. It is a specification of USB-C cables for managing power when powering devices with the USB-C port, such as now almost all the latest smartphones, notebooks, tablets, netbooks, etc. Basically inside the E-Mark cable there is an electronic circuit.

This circuit allows the charger and the mobile device to communicate and correctly manage the current flowing between them and to take full advantage of the PD (Power Delivery) protocol for fast charging, where it is specified that the maximum maximum charging current is 100 Watt, i.e. 5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/5A.

The E-Mark chip optimizes the power exchange between devices, does not affect the data transmission speed. Data transmission does not use the same conductors as the current inside the cable.

Even if you don't need to go beyond 3A of current, using a cable with E-Mark will optimize the current and stabilize it, avoiding wasted energy and prolonging battery life. For example, you can use a USB-C 3.1 (Gen 1) cable which according to specifications must reach 5 Gbps and 3A, even without E-Mark. But the USB 3.1 (Gen 2) 10 Gbps standard specifies a maximum current of 100 watts (corresponding to 20V/5A therefore more than 60 Watts – 20V/3A), and to take full advantage of this potential you must use an E-Mark cable .

In summary: a USB-A / USB-C cable cannot exceed 3 amps of current. To reach 5 Amperes and take advantage of fast charging you must use

1) a USB-C male/male cable, e
2) the cable must have the E-Mark.

When buying a battery charger, it is therefore advisable to make sure that there is a USB-C connector, as well as Fast Charge/Quick Charging with the relevant voltage modulation.