A multilevel sensing and program verifying scheme for Bi-NAND flash memories

A multi-level sensing and program verifying circuit is proposed for Bi-NAND type flash memories. The sensing circuit utilizes the advanced cross-coupled sense amplifier to achieve excellent immunity against mismatch effect, and reduce power consumption. The program-verifying scheme with dichotomous architecture simplifies the verifying circuit and speeds up verification process for multi-level cell arrays.