Usb-pd interface and associated method

A method implemented in a power supply interface, the method comprising:

• delivering a first direct current (DC) voltage on a first terminal of the interface;
• delivering, by a first comparator of the interface, a first signal representative of a comparison of the first DC voltage with a high threshold;
• delivering, by a second comparator of the interface, a second signal representative of a comparison of the first DC voltage with a low threshold;
• detecting, by a first circuit of the interface, that the first DC voltage becomes smaller than a first value of the low threshold based on the second signal;
• delivering, by the first circuit, successive pairs of values of the high and low thresholds for a first time period after the detection;
• modifying, by the first circuit, the values of the high and low thresholds between two successive pairs based on the first and second signals to determine a pair of values of the high and low thresholds surrounding the first DC voltage;
• and
• determining, by the first circuit, a current value of the first DC voltage based on the pair of values of the high and low thresholds surrounding the first DC voltage.