Patent ID: 8073648

Claim:
A method for operating a memory device, comprising: pre-charging respective bit lines, each respective bit line is connected to one end of a respective NAND string on a memory die, and each of the respective NAND strings has a respective non-volatile storage element in communication with a word line; generating a voltage sweep internally from within the memory; applying the voltage sweep to the word line, each respective bit line discharging through the respective NAND string to which the respective bit line is connected, and to a common source line which is connected to another end of each of the respective NAND strings, when the voltage sweep causes the respective non-volatile storage element to transition from a non-conductive state to a conductive state; determining when each of the respective non-volatile storage elements transitions from the non-conductive state to the conductive state; measuring an aggregate characteristic of the non-volatile storage elements while applying the voltage sweep, the aggregate characteristic is measured by a measurement device which is connected to the common source line; determining a threshold voltage distribution of the non-volatile storage elements based on the aggregate characteristic; and based on the step of determining when each of the respective non-volatile storage elements transitions from the non-conductive state to the conductive state, and while applying the voltage sweep to the word line: locking out each of the respective non-volatile storage elements which transitions from the non-conductive state to the conductive state while applying the voltage sweep, so that the respective non-volatile storage elements which are locked out no longer contribute to the characteristic.