US Patent 7099213 Page buffer for flash memory device

The disclosed is a page buffer of a flash memory device. In accordance with the present invention, a latch is controlled through a program verification signal, a latch signal, and latch data in a page buffer during a program verification. As a result, there are many advantages. First, in the event that the program verification is performed after programming once more, a passed cell is not sensed again and maintains its value. Second, it is possible to prevent a problem caused by a sensing operation as well as a verification error due to an external factor. As a result, program operation errors can be prevented.