Patent ID: 8922180

Claim:
A method for supplying an internal power supply of a DC-DC switching converter, comprising: defining first and second thresholds of discrimination of an output voltage of the DC-DC switching converter, tied to a reference voltage; defining three regions of operation of the converter, based on ranges of values of the output voltage of the converter relative to the first and second thresholds of discrimination; while the output voltage of the converter is lower that the first threshold of discrimination, operating the converter in a first one of the three regions of operation, including: enabling a first linear regulator coupled to an input voltage of the converter, and disabling a second linear regulator coupled to the output voltage of the converter, including placing in a high impedance state an output stage of the second linear regulator; while the output voltage is greater than the second threshold of discrimination, operating the converter in a second of the three regions of operation, including: disabling said first linear regulator connected to the input voltage, including placing in a high impedance state an output stage of said first linear regulator, and enabling said second linear regulator connected to the output voltage; and while the output voltage is equal or greater than said first threshold and lower than or equal to said second threshold, operating the converter in a third one of the three regions of operation, including: disabling said first linear regulator, including placing in a high impedance state the output stage of said first linear regulator, and disabling said second linear regulator, including placing in a low impedance state the output stage of the second linear regulator.