Page buffer and semiconductor memory device having the page buffer

1. A page buffer comprising:

a first latch circuit configured to store data corresponding to one of a first program state and a second program state;

a bit line controller connected to a bit line of a memory block and configured to precharge the bit line by applying one of a first set voltage and a second set voltage to the bit line according to the data stored in the first latch circuit during a bit line precharge operation in a program verify operation; and

a second latch circuit connected to the bit line controller through a main sensing node and configured to sense first verify data according to a potential level of the main sensing node during the program verify operation.

2. The page buffer of claim 1 , wherein the first program state and the second program state are program states in which threshold voltage distributions are adjacent to each other among a plurality of program states.

3. The page buffer of claim 2 , wherein if the data stored in the first latch circuit corresponds to the first program state, the bit line controller precharges the bit line to the first set voltage, and

wherein, if the data stored in the first latch circuit corresponds to the second program state, the page buffer precharges the bit line to the second set voltage of which a potential level is higher than a potential level of the first set voltage.

4. The page buffer of claim 3 , wherein a threshold voltage distribution of the first program state is lower than a threshold voltage distribution of the second program state.

5. The page buffer of claim 3 , wherein the bit line controller comprises:

a first transistor connected between the bit line and a first common node, and configured to connect the bit line and the first common node to each other in response to a first page buffer sensing signal;

a second transistor connected between the first common node and a second common node, and configured to form a first current path by connecting the first common node and the second common node to each other in response to a second page buffer sensing signal;

a third transistor connected between the first common node and the second common node, and configured to form a second current path by connecting the first common node and the second common node to each other in response to a first node potential of the first latch circuit; and

a fourth transistor connected to the second common node and configured to apply a power voltage to the second common node in response to a control signal.

6. The page buffer of claim 5 , wherein the first page buffer sensing signal is activated to a first level and the second page buffer sensing signal is activated to a second level during the bit line precharge operation, and

wherein the second level is lower than the first level.

7. The page buffer of claim 6 , wherein if the data corresponding to the first program state is stored in the first latch circuit, the first node potential is set to a third level, if the data corresponding to the second program state is stored in the first latch circuit, the first node potential is set to a fourth level, and

wherein the third level is a ground power level, and the fourth level is a power voltage level.

8. The page buffer of claim 7 , wherein the fourth level is higher than the second level.

9. The page buffer of claim 5 , wherein the bit line controller further includes a fifth transistor connected between the second common node and the main sensing node and electrically connecting the second common node and the main sensing node to each other in response to a transmission signal, and

wherein the fifth transistor performs an evaluation operation of controlling a potential level of the main sensing node according to a current amount of the bit line by connecting the second common node and the main sensing node to each other in an evaluation operation after the bit line precharge operation.

10. The page buffer of claim 1 , further comprising:

a sensing node connection component connected between the main sensing node and a sub sensing node; and

a third latch circuit connected to the sub sensing node and configured to sense second verify data according to a potential level of the sub sensing node during the program verify operation.

11. The page buffer of claim 10 , wherein the first verify data corresponds to a program verify result for the second program state, and

the second verify data corresponds to a program verify result for the first program state.

12. The page buffer of claim 10 , wherein the main sensing node and the sub sensing node perform an evaluation operation through the bit line controller after the bit line precharge operation, and

wherein the sensing node connection component electrically connects the main sensing node and the sub sensing node to each other during a first period during the evaluation operation, and electrically disconnect the main sensing node and the sub sensing node from each other during a second period after the first period.

13. The page buffer of claim 12 , wherein the evaluation operation is performed on the main sensing node during the first period and the second period, and

wherein the evaluation operation is performed on the sub sensing node during the first period.

14. The page buffer of claim 13 , wherein the evaluation operation corresponding to the second program state is performed on the main sensing node, and

wherein the evaluation operation corresponding to the first program state is performed on the sub sensing node.