Control system for memory device

摘要

A nonvolatile memory device includes a discharge circuit configured to selectively connect circuit nodes to discharge terminals through corresponding discharge paths, and an accumulation device for accumulating electric charge. A driving circuit is for driving the discharge circuit in such a way to connect at least a part of such circuit nodes to the discharge terminals if the value of the external supply voltage falls below a corresponding threshold. A supply circuit is for supplying the driving circuit with an intermediate supply voltage. Each one of the intermediate supply voltages is the corresponding external supply voltage when the value of the external supply voltage is higher than the corresponding threshold, or it is an internal voltage locally generated by the supply circuit by exploiting the electric charge stored by the accumulation device when the value of the external supply voltage is lower than the corresponding threshold.

主权项

1. A nonvolatile memory device integrated in a semiconductor material chip, the memory device configured to be supplied via at least one external supply voltage, the memory device comprising:
a plurality of circuit nodes; a plurality of discharge terminals; a discharge circuit configured to selectively couple circuit nodes to respective discharge terminals through corresponding discharge paths; an accumulation device configured to accumulate electric charge; a driving circuit configured to drive the discharge circuit to couple at least some of the circuit nodes to the discharge terminals if the value of the at least one external supply voltage falls below a corresponding threshold; a supply circuit configured to supply the driving circuit with a respective intermediate supply voltage for the at least one external supply voltage; each intermediate supply voltage being defined by the corresponding external supply voltage when the value of the external supply voltage is higher than the corresponding threshold, and defined by an internal supply voltage locally generated by the supply circuit based upon the electric charge stored by the accumulation device when the value of the corresponding external supply voltage is lower than the corresponding threshold; and a generating circuit coupled to the accumulation device and configured to generate the internal supply voltage when the value of the external supply voltage is lower than the threshold, wherein said generating circuit comprises a regulation transistor having a control terminal, and an amplifier having a supply terminal coupled to the accumulation device and having an output terminal coupled to the control terminal of the regulation transistor, the regulation transistor having a first conduction terminal coupled to the accumulation device and a second conduction terminal defining an output terminal.