Method for precharging an integrated-circuit supply, and corresponding integrated circuit

An electronic apparatus, comprising an integrated circuit comprising:

• a primary supply stage comprising a primary supply node, the primary supply stage being configured to deliver a primary supply voltage to the primary supply node;
• a secondary supply stage comprising a secondary supply node, the secondary supply stage being configured to deliver a secondary supply voltage to the secondary supply node;
• a supply-switching circuit;
• a pre-charging circuit controllably coupled to the secondary supply node via the supply-switching circuit;
• and
• a volatile memory circuit controllably coupled to the primary supply node and the secondary supply node via the supply-switching circuit, wherein the supply-switching circuit is configured to connect a supply of the volatile memory circuit either to the primary supply node in a primary supply mode, or to the secondary supply node in a secondary supply mode, the secondary supply stage being configured to supply the secondary supply node with the secondary supply voltage during the primary supply mode.

A method for supplying power to an integrated circuit comprising a primary supply stage having a primary supply node, a secondary supply stage having a secondary supply node, and a volatile memory circuit, the method comprising:

• delivering a primary supply voltage to the volatile memory circuit during a primary supply mode, wherein the primary supply mode comprises:
• passing, during a pre-charging phase, a replica current through a replica circuit that is connected to the secondary supply node, the replica circuit having an identical configuration as at least one portion of the volatile memory circuit;
• generating a pre-charging current from the replica current, the pre-charging current being representative of a current passed by the volatile memory circuit in a secondary supply mode;
• and
• passing the pre-charging current to the secondary supply node;
• delivering a secondary supply voltage to the volatile memory circuit during the secondary supply mode;
• and
• delivering the secondary supply voltage to the secondary supply node in the primary supply mode.