Smartcard providing an improved standby mode

摘要

The invention relates to a smartcard (10) comprising: —a microcontroller (30); —a contact communication interface (11); —a supply line (Vcc) connecting the contact communication interface to the microcontroller, a clock line (Clk) connecting the contact communication interface to the microcontroller. The smartcard further comprises a power management circuit (20) including a switch (23) adapted to selectively open or close the supply line connection between the contact communication interface and the microcontroller, the power management circuit being adapted to detect the loss of a clock signal on the clock line (Clk), adapted to keep said switch closed during a predetermined period after a loss of clock signal is detected and adapted to open said switch after said predetermined period.

主权项

1. A smart card comprising:
a microcontroller; a contact communication interface; a power supply line connecting the contact communication interface to the microcontroller; a clock line connecting the contact communication interface to the microcontroller; a power management circuit including a switch adapted to selectively open or close the power supply line connection between the contact communication interface and the microcontroller, the power management circuit being adapted to detect the loss of a clock signal on the clock line, adapted to keep said switch closed during a predetermined period after a loss of clock signal is detected and adapted to open said switch after said predetermined period.