Current metering for transitioning between operating modes in switching regulators

An apparatus comprising:

• a pulse timer that is used to generate charging cycles in accordance with a first operating mode or a second operating mode, wherein the charging cycles enable current to flow to an inductor to adjust an output voltage;
• a minimum on-time generator that generates a first minimum on-time in the first operating mode and a second minimum on-time in the second operating mode, wherein the first minimum on-time is based on a ratio of an input voltage to the output voltage utilizing a first factor K1, wherein the second minimum on-time is based on the ratio of the input voltage to the output voltage utilizing a second factor K2, and wherein the first factor K1 and the second factor K2 are not the same;
• and
• a mode controller that detects a skipped charging cycle and determines whether a selected number of charging cycles is skipped over a selected time interval that begins when the skipped charging cycle is detected, and wherein the mode controller transitions the apparatus from the first operating mode to the second operating mode if the mode controller determined that the selected number of charging cycles is skipped over the selected time interval.

A switching regulator, wherein the switching regulator converts an input voltage to an output voltage, wherein the switching regulator generates an inductor current that flows through an inductor, wherein the switching regulator is operable in a first mode and in a second mode, and wherein the switching regulator comprises:

• a minimum on-time generator, wherein in the first mode, the minimum on-time generator generates a first minimum on-time that is determined using a first factor K1 and a ratio of the input voltage and the output voltage, wherein in the second mode, the minimum on-time generator generates a second minimum on-time that is determined using a second factor K2 and the ratio of the input voltage and the output voltage, wherein the switching regulator switches from the first mode to the second mode in response to determining that an on-time of the switching regulator is less than the first minimum on-time, and wherein the first factor K1 and second factor K2 are different;
• and
• a mode controller that detects a skipped charging cycle and determines whether a selected number of charging cycles is skipped over a selected time interval that begins when the skipped charging cycle is detected, and wherein the mode controller transitions the switching regulator from the first mode to the second mode if the mode controller determined that the selected number of charging cycles is skipped over the selected time interval.