Patent ID: 6597603
Filing Date: 2003-07-22
Classification: G11C

Abstract:
A dual mode high voltage power supply circuit for providing increased speed in programming during testing of low voltage nonvolatile memories, said circuit comprising:a charge pump receiving an external power supply low voltage (VDD) on an input and producing a programming high voltage (VM) on an output, the charge pump having a clock input for receiving a timing signal; an external high voltage switch having a first input terminal, a second input terminal, an output terminal, and a plurality of enable inputs, said external high voltage switch receiving an external power supply high voltage (VPP) at the first input terminal, receiving the external power supply low voltage (VDD) at the second input terminal and producing the programming high voltage (VM) at the output terminal, said output terminal being connected to the output of the charge pump at a common programming node, the external voltage switch being activated and deactivated by a fast program enable signal applied to a first one of the enable inputs; a plurality of nonvolatile memory blocks, each nonvolatile memory block being connected to a memory block switch having a programming input terminal connected to the common programming node to receive the programming voltage, and each memory block switch having a control input terminal for receiving a signal to activate or deactivate the memory block switch, each of the nonvolatile memory blocks being programmed with the programming voltage when its respective memory block switch is activated; a programming control circuit having an input terminal for receiving the fast program enable signal and a plurality of output terminals being connected to the control input terminals of the memory block switches; and means for generating the timing signals for the charge pump, whereby the dual mode high voltage power supply operates in a first programming mode when the external high voltage switch is deactivated and the dual mode high voltage power supply operates in a second programming mode when the external high voltage switch is activated.