Non-volatile memory device and data read method and program verify method of non-volatile memory device
View Patent ↗A non-volatile memory device includes an even bit line and an odd bit line, a first register, a second register, a first precharge unit, a second precharge unit and a bit line select unit. The even bit line and the odd bit line are connected to a memory cell array. The first register is connected to the even bit line and configured to store specific data. The second register is connected to the odd bit line and configured to store specific data. The first precharge unit precharges an even sense node, formed at a node of the even bit line and the first register, with a high level or supplies supplementary current to the even sense node. The second precharge unit precharges an odd sense node, formed at a node of the odd bit line and the second register, with a high level or supplies supplementary current to the odd sense node. The bit line select unit connects the even bit line and the even sense node and connects the odd bit line and the odd sense node.
1. A non-volatile memory device, comprising:
an even bit line and an odd bit line connected to a memory cell array;
a first register coupled to the even bit line and configured to store data;
a second register coupled to the odd bit line and configured to store data;
a first precharge unit to precharge an even sense node with a high level or supplying supplementary current, the even sense node defined at a node associated with the even bit line and the first register;
a second precharge unit to precharge an odd sense node with a high level or supplying supplementary current the odd sense node defined at a node associated with the odd bit line and the second register, wherein the odd sense node is electrically isolated from the even sense node; and
a bit line select unit to connect the even bit line and the even sense node and connect the odd bit line and the odd sense node.
2. The non-volatile memory device of claim 1 , wherein the bit Line select unit comprises:
a first NMOS transistor to connect the even bit line and the even sense node in response to a first bit line select signal;
a second NMOS transistor to connect the odd bit line and the odd sense node in response to a second bit line select signal.
3. The non-volatile memory device of claim 2 , wherein the first bit line select signal and the second bit line select signal are applied at substantially the same time when the even bit line and the even sense node are connected and when the odd bit line and the odd sense node are connected.
4. The non-volatile memory device of claim 1 , wherein the bit line select unit comprises:
a control signal input terminal to apply a control signal of a specific level;
a third NMOS transistor to connect the even bit line and the control signal input terminal in response to a first discharge signal; and
a fourth NMOS transistor to connect the odd bit line and the control signal input terminal in response to a second discharge signal.
5. The non-volatile memory device of claim 4 , wherein the first discharge signal and the second discharge signal are applied substantially at the same time when the even bit line and the control signal input terminal are connected and when the odd bit line and the control signal are connected.
6. The non-volatile memory device of claim 1 , wherein the first precharge unit comprises:
a first PMOS transistor to apply a power supply voltage to the even sense node in response to a first precharge signal of a low level;
a second PMOS transistor to supply supplementary current to the even sense node in response to a second precharge signal of a low level; and
a third PMOS transistor connected to a drain of the second PMOS transistor and the even sense node, and configured to prevent countercurrent of current passing through the second PMOS transistor, wherein the third PMOS transistor is diode-connected.
7. The non-volatile memory device of claim 1 , wherein the second precharge unit comprises:
a fourth PMOS transistor to apply a power supply voltage to the odd sense node in response to a first precharge signal of a low level;
a fifth PMOS transistor to supply supplementary current to the odd sense node in response to a second precharge signal of a low level; and
a sixth PMOS transistor connected to a drain of the fifth PMOS transistor and the even sense node, and configured to prevent countercurrent of current passing through the fifth PMOS transistor, wherein the sixth PMOS transistor is diode-connected.
8. A data read method for a non-volatile memory device, the method comprising:
providing a non-volatile memory device including a first precharge unit to precharge an even sense node with a high level or supplying supplementary current, the even sense node being defined at a node associated with an even bit line and a first register, and a second precharge unit to precharge an odd sense node with a high level or supplying supplementary current, the odd sense node being defined at a node associated with an odd bit line and a second register;
allowing the first precharge unit and the second precharge unit to precharge the even sense node and the odd sense node individually with a high level;
applying a bit line select signal of a high level to connect the even bit line and the even sense node, and the odd bit line and the odd sense node at substantially the same time;
turning on a drain select transistor to connect a cell string and each of the bit lines, the cell string including a memory cell to be read;
applying voltage of a low level to a word line connected to the specific memory cell, and applying voltage of a high level to the remaining word lines;
turning on a source select transistor to connect one terminal of the cell string to a common source line connected to ground voltage;
allowing the first precharge unit and the second precharge unit to supply supplementary current to the even sense node and the odd sense node; and
evaluating whether the memory cell to be read has been programmed using variation in a voltage level of each of the bit lines, and applying a read signal so that a voltage level of a specific cell is applied to the first register and the second register, respectively.
9. The data read method of claim 8 , the method further comprising:
applying a discharge signal of a high level to NMOS transistors connected between an input terminal of a control signal and a pair of the even bit line and the odd bit line at substantially the same time;
connecting each of the bit lines and the control signal input terminal before the precharge step is performed; and
applying a specific voltage of a low level to the control signal input terminal to discharge each of the bit lines.
10. The data read method of claim 8 , wherein the step of precharging the even sense node and the odd sense node with a high level comprises the step of applying a first precharge signal of a low level to a gate of a first PMOS transistor connected between a power supply voltage and each sense node such that each sense node is connected to the power supply voltage.
11. The data read method of claim 10 , wherein the step of supplying the supplementary current to the even sense node and the odd sense node comprises:
applying a second precharge signal of a low level to a gate of a second PMOS transistor connected to power supply voltage, so that supplementary current is supplied from the power supply voltage through a third PMOS transistor connected between a drain of the second PMOS transistor and each sense node, the third PMOS transistor being diode-connected; and
shifting the first precharge signal to a high level in order to stop the precharge of each sense node.
12. A program verify method of a non-volatile memory device, the method comprising:
providing a non-volatile memory device including a second precharge unit for precharging an even sense node with a high level or supplying supplementary current, the even sense node being defined at a node associated with an even bit line and a first register, and a second precharge unit for precharging an odd sense node with a high level or supplying supplementary current, the odd sense node being defined at a node associated with an odd bit line and a second register;
allowing the first precharge unit and the second precharge unit to precharge the even sense node and the odd sense node individually with a high level;
applying a bit line select signal of a high level to connect the even bit line and the even sense node, and the odd bit line and the odd sense node at the same time;
turning on a drain select transistor to connect a cell string and each of the bit lines, the cell string including a specific memory cell to be read;
applying a verify reference voltage to a word line connected to the specific memory cell, and applying voltage of a high level to the remaining word lines;
turning on a source select transistor to connect one terminal of the cell string to a common source line connected to ground voltage;
allowing the first precharge unit and the second precharge unit to supply supplementary current to the even sense node and the odd sense node; and
evaluating whether the memory cell to be read has been programmed using variation in a voltage level of each of the bit lines, and applying a read signal so that a voltage level of a specific cell is applied to the first register and the second register, respectively.
13. The program verify method of claim 12 , further comprising:
applying a discharge signal of a high level to NMOS transistors connected between an input terminal of a control signal and a pair of the even bit line and the odd bit line at substantially the same time;
connecting each of the bit lines and the control signal input terminal before the precharge step is performed; and
applying a specific voltage of a low level to the control signal input terminal to discharge each of the bit lines.
14. The program verify method of claim 12 , wherein the step of precharging the even sense node and the odd sense node with a high level comprises the step of applying a first precharge signal of a low level to a gate of a first PMOS transistor connected between a power supply voltage and each sense node such that each sense node is connected to the power supply voltage.
15. The program verify method of claim 14 , wherein the step of supplying the supplementary current to the even sense node and the odd sense node comprises:
applying a second precharge signal of a low level to a gate of a second PMOS transistor connected to power supply voltage, so that supplementary current is supplied from the power supply voltage through a third PMOS transistor connected between a drain of the second PMOS transistor and each sense node, the third PMOS transistor being diode-connected; and
shifting the first precharge signal to a high level in order to stop the precharge of each sense node.
16. A non-volatile memory device, comprising:
an even bit line and an odd bit line connected to a memory cell array;
a first register coupled to the even bit line and configured to store data;
a second register coupled to the odd bit line and configured to store data;
a first precharge unit configured to precharge an even sense node with a high level or to supply supplementary current, wherein the even sense node is defined at a node associated with the even bit line and the first register;
a second precharge unit configured to precharge an odd sense node with a high level or to supply supplementary current, wherein the odd sense node is defined at a node associated with the odd bit line and the second register; and
a bit line select unit configured to couple the even bit line and the even sense node and to couple the odd bit line and the odd sense node.