Two USB-C cables can look identical and charge very differently. Cables rated for 5 A carry an electronically marked (e-marker) chip that the charger powers and queries with a USB Power Delivery Discover Identity message addressed to the cable. The reply reports vendor, speed support and whether the cable handles 3 A or 5 A. With no answer the charger must assume 3 A, which is 60 W at 20 V, while a 5 A cable reaches 100 W and, with Extended Power Range, up to 240 W. Sources: USB-IF USB Type-C and USB PD documentation, Microchip AN1974.
#USBC #USBPD #Hardware #Charging #Shorts
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