Internal voltage generator

1. An internal voltage generation device, comprising:

a plurality of output nodes;

a bit line precharge voltage generation unit for generating a bit line precharge voltage;

a first voltage drop unit for transferring the bit line precharge voltage to a first output node after decreasing the bit line precharge voltage by a first voltage drop amount in response to a test mode signal; a second voltage drop unit for transferring the bit line precharge voltage to a second output node after decreasing the bit line precharge voltage by a second voltage drop amount in response to the test mode signal;

a first control unit for controlling the first voltage drop unit; and

a second control unit for controlling the second voltage drop unit; and

wherein the second voltage drop amount is greater than the first voltage drop amount,

wherein the first and second control units include a plurality of fuse cutting circuits for fixing output signals of the first and second control units by performing a fuse cutting operation,

wherein the test mode signal is outputted from a test mode unit included for selecting a voltage drop amount according to a leakage current, and

wherein the first control unit includes:

a first NAND gate for receiving a first test mode signal and a first fuse cut signal of the fuse cutting circuit;

a first inverter for inverting an output of the first NAND gate;

a second NAND gate for receiving a second test mode signal and a second fuse cut signal;

a second inverter for inverting an output of the second NAND gate;

a third NAND gate for receiving each output of the first and second inverters; and

a third inverter for inverting an output of the third NAND gate.

2. The internal voltage generation device as recited in claim 1 , wherein the second voltage drop unit includes at least one voltage drop transistor connected between the second output node and the bit line precharge voltage generation unit.

3. The internal voltage generation device as recited in claim 2 , wherein the voltage drop transistors are a plurality of PMOS transistors which have a different gate length.

4. The internal voltage generation device as recited in claim 1 , wherein the first voltage drop unit comprises a slim-typed NMOS transistor.

5. The internal voltage generation device as recited in claim 1 , wherein the second control unit includes:

a fourth NAND gate for receiving outputs of the first NAND gate and the second inverter; and

a fourth inverter for inverting an output of the fourth NAND gate.

6. The internal voltage generation device as recited in claim 1 , wherein each fuse cutting circuit includes:

a PMOS transistor whose gate receives an enable signal;

a first NMOS transistor whose gate receives a power-up signal;

a fuse connected between the PMOS transistor and the first NMOS transistor;

a first inverter for inverting a signal at a common output terminal of the fuse and the first NMOS transistor;

a second NMOS transistor whose gate receives an output of the first inverter; and

a second inverter for inverting an output of the first inverter in order to output the inverted signal.

7. An internal voltage generation device, comprising:

a precharge voltage supply unit for supplying a bit line precharge voltage to a semiconductor memory device;

a voltage drop unit for dropping a voltage level of the bit line precharge voltage due to a leakage current generated due to a bridge between a word line and a bit line; a voltage drop control unit for controlling output voltages of the voltage drop unit in response to test mode signals and fuse cutting signals; and

a fuse cutting unit which includes a plurality of fuse cutting circuits for generating the fuse cutting signals by selecting a voltage drop amount based on a pre-measured leakage current amount when the voltage level of the bit line precharge voltage is dropped, and

wherein the voltage drop control unit includes:

an intermediate signal generation unit for generating first and second intermediate signals;

a normal path control unit for generating a normal path control signal based on the first and second intermediate signals; and

first and second voltage drop path control units for generating first and second voltage drop control signals based on the first and second intermediate signals; and

a fuse cutting unit which includes a plurality of fuse cutting circuits for generating the fuse cutting signals by selecting a voltage drop amount based on a pre-measured leakage current amount when the voltage level of the bit line precharge voltage is dropped, and

wherein the voltage drop control unit includes;

an intermediate signal generation unit for generating first and second intermediate signals;

a normal path control unit for generating a normal path control signal based on the first and second intermediate signals; and

first and second voltage drop path control units for generating first and second voltage drop control signals based on the first and second intermediate signals.

8. The internal voltage generation device as recited in claim 7 , wherein each fuse cutting circuit includes:

a PMOS transistor whose gate receives an enable signal;

a first NMOS transistor whose gate receives a power-up signal;

a fuse connected between the PMOS transistor and the first NMOS transistor;

a first inverter for inverting a signal at a common output terminal of the fuse and the first NMOS transistor;

a second NMOS transistor whose gate receives an output of the first inverter; and

a second inverter for inverting an output of the first inverter in order to output the inverted signal as a corresponding one of the fuse cutting signals.

9. The internal voltage generation device as recited in claim 7 , wherein the intermediate signal generation unit includes:

a first NAND gate for receiving a first test mode signal and a first fuse cut signal to generate the first intermediate signal; and

a second NAND gate for receiving a second test mode signal and a second fuse cut signal to generate the second intermediate signal.

10. The internal voltage generation device as recited in claim 7 , wherein the normal path control unit includes:

a first inverter for inverting the first intermediate signal;

a second inverter for inverting the second intermediate signal;

a NAND gate for receiving outputs of the first and second inverters; and

a third inverter for inverting an output of the NAND gate to output the inverted signal as the normal path control signal.

11. The internal voltage generation device as recited in claim 7 , wherein the first voltage drop path control unit includes:

a NAND gate for receiving the first intermediate signal and the output of the second inverter; and

a fourth inverter for inverting an output of the NAND gate in order to output the inverted signal as the first voltage drop control signal.

12. The internal voltage generation device as recited in claim 7 , wherein the second voltage drop path control unit includes a buffer unit for buffering the second intermediate signal in order to output the buffered signal as the second voltage drop control signal.

13. The internal voltage generation device as recited in claim 7 , wherein the voltage drop unit includes:

a normal operation unit for supplying the bit line precharge voltage to the precharge voltage supply unit in response to the normal path control signal when the semiconductor memory device is in a normal operation;

a first voltage drop unit for supplying a first voltage-dropped bit line precharge voltage to the precharge voltage supply unit in response to the first voltage drop control signal when the semiconductor memory device is in a standby mode; and

a second voltage drop unit for supplying a second voltage-dropped bit line precharge voltage to the precharge voltage supply unit in response to the second voltage drop control signal when the semiconductor memory device is in the standby mode.

14. The internal voltage generation device as recited in claim 13 , wherein the first voltage-dropped bit line precharge voltage is greater than the second voltage-dropped bit line precharge voltage.