Patent ID: 8890495

Claim:
A power supply for providing a supply voltage to an integrated circuit, comprising: a high power regulator that regulates the supply voltage at a first voltage level when the integrated circuit is in a RUN mode and wherein the supply voltage is maintained at a second voltage level when the integrated circuit transitions from the RUN mode to a STOP mode; a low power regulator that is set in an inactive mode when the integrated circuit is in the RUN mode, and regulates the supply voltage at a third voltage level when the integrated circuit transitions from the RUN mode to the STOP mode; and a power management circuit, connected to the high and low power regulators, and including: a first voltage monitoring circuit that monitors the supply voltage regulated by the low power regulator when the integrated circuit transitions from the RUN mode to the STOP mode and generates a fallback signal when the supply voltage regulated by the low power regulator drops below a first voltage threshold; and a control circuit that sets the low power regulator in the inactive mode and configures the high power regulator to regulate the supply voltage at a fourth voltage level when the fallback signal is active during a predefined time period when the integrated circuit transitions from the RUN mode to the STOP mode, and wherein the control circuit switches off the high power regulator and configures the low power regulator to continue regulating the supply voltage at the third voltage level when the fallback signal is not active during the predefined time period.