US Patent 7679945 Persistent volatile memory with sense amplifier and discharge switch

A persistent volatile memory cell memorizes a binary datum during a retention time independent from a supply voltage of the memory cell. The memory cell comprises a capacitive memory point supplying a persistent voltage and having a determined discharge time, a switch for triggering the discharge of the memory point when an erase signal has an active value, a switch for triggering the charge of the memory point when a write signal has an active value, and a sense-amplifier circuit having an input receiving the persistent voltage, and an output supplying the binary datum. The memory cell can be applied to the management of an inventory flag in a contactless integrated circuit.