Unselected sub-block source line and bit line pre-charging to reduce read disturb

Abstract

A memory device includes unselected sub-block, which includes bit line; drain select (SGD) transistor coupled with bit line; a source voltage line; source select (SGS) transistor coupled with source voltage; and wordlines coupled with gates of string of cells, which have channel coupled between the SGS/SGD transistors. Control logic coupled with unselected sub-block is to: cause the SGD/SGS transistors to turn on while ramping the wordlines from a ground voltage to a pass voltage associated with unselected wordlines in preparation for read operation; cause, while ramping the wordlines, the channel to be pre-charged by ramping voltages on the bit line and the source voltage line to a target voltage that is greater than a source read voltage level; and in response to wordlines reaching the pass voltage, causing the SGD and SGS transistors to be turned off, to leave the channel pre-charged to the target voltage during the read operation.