Patent ID: 11934217
Assignee: STMICROELECTRONICS RAZVOJ POLPREVODNIKOV D.O.O.
Field: Control (Instruments)
Classification: CPC G | IPC G

Claim 16:
17. A method of operating an integrated circuit card comprising a voltage regulator having an amplifier, a first transistor coupled between a first supply terminal and voltage regulator output, and a second transistor coupled between a second supply terminal and the voltage regulator output, the method comprising:
determining whether the a voltage of the first supply terminal is greater than a voltage of the second supply terminal, determining comprising using a selection circuit comprising:
a comparator configured to compare the voltage of the first supply terminal and the voltage of the second supply terminal,
a first diode coupled between the first supply terminal and a supply terminal of the comparator,
a second diode coupled between the second supply terminal and the supply terminal of the comparator, and
a capacitor coupled between the supply terminal of the comparator and a supply node;

coupling the first supply terminal to a power supply node of the amplifier and to a control node of the first transistor and disabling the second transistor when the voltage of the first supply terminal is greater than the voltage of the second supply terminal; and
coupling the second supply terminal to the power supply node of the amplifier and to a control node of the second transistor and disabling the first transistor when the voltage of the first supply terminal is not greater than the voltage of the second supply terminal.