An electrically programmable non-volatile memory device comprises a memory circuit which includes an array of non-volatile memory cells. Each memory cell is capable of being programmed. A programming circuit can generate a programming signal to program one or more of the memory cells. A voltage detector circuit is connected to a voltage source which outputs a certain voltage. The voltage detector circuit detects when the certain voltage has decreased to a certain level, and in response thereto, the voltage detector provides an output signal to the memory controller to complete the on-going programming command sequence and to power down itself. An auxiliary voltage source maintains voltage to the memory circuit for a period of time sufficient for the programming circuit to complete the programming of the one or more of the memory cells, when the certain voltage is at or below the certain level.