Systems and methods for measuring inductor current in a switching DC-to-DC converter

A direct current-to-direct current (DC-DC) switch converter, comprising:

• a switch control circuit coupled to a first switch and a second switch for controlling the first switch and the second switch in a continuous conduction mode;
• an inductor coupled to the first switch and the second switch;
• a sensor coupled to the inductor for sensing an inductor current;
• a capacitor capable of being coupled in parallel with a load and coupled to the inductor wherein the capacitor provides an output for the DC-DC switch converter;
• and wherein the switch control circuit utilizes a sequence of switching events wherein the switching events are events that occur in an order of a first event, a second event, a third event, and a fourth event for:
• performing the first event to activate the first switch and deactivate the second switch wherein the inductor current increases during the first event and has a positive value at an end of the first event;
• performing the second event to deactivate the first switch and activate the second switch wherein the switch control circuit maintains the inductor current above zero during the second event;
• performing the third event to activate the first switch and deactivate the second switch;
• and performing the fourth event to deactivate the first switch and activate the second switch wherein the inductor current decreases to a value below zero at an end of the fourth event and when the inductor current reaches zero, a zero crossing time point is defined, wherein the first event, the second event, the third event, and the fourth event occur in immediately successive order and are repeated during consecutively successive periods of time;
• and measuring a time period from the zero crossing time point relative to a time point within the sequence of switching events.