Open block detection using current consumption peak during fourth time period of read operation and method of lowering current consumption for non-volatile memory apparatus

Abstract

A memory apparatus and method of operation are provided. The apparatus includes memory cells configured to retain a threshold voltage and disposed in memory holes coupled to bit lines and grouped into blocks. A control means is configured to determine an amount of the memory cells of one of the blocks that are programmed based on an electrical current consumed by the memory apparatus during a fourth period of time of a read operation in which selected ones of the bit lines are ramped up to a bit line voltage. The control means adjusts at least one read parameter accordingly. The control means is also configured to utilize the adjusted at least one read parameter while reading the memory cells to determine if the memory cells have the threshold voltage above one or more read levels associated with each of the data states in the read operation.