Internal voltage generator of semiconductor memory device

• US 7,250,811 B2
• Filed: 12/30/2004
• Issued: 07/31/2007
• Est. Priority Date: 10/29/2004
• Status: Active Grant

• Current Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Original Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Inventors: Kim, Kyung-Whan
• Primary Examiner(s): Cox; Cassandra
• Application Number:
  US11/026,994
• Publication Number:
  US 20060091938A1
• Time in Patent Office: 943 Days
• Field of Search: 327/538, 327540-541, 327543-546
• US Class Current: 327/538
• CPC Class Codes: G05F 1/465 Internal voltage generators for integrated circuits, e.g. step down generators
• CPC Class Codes: G11C 5/147 Voltage reference generators, voltage or current regulators; Internally lowered supply levels; Compensation for voltage drops G11C5/141 takes precedence

Abstract

The present invention provides an internal voltage generator for maintaining a voltage level of an internal voltage by forcibly discharging an over-supplied voltage. The internal voltage generator includes a reference voltage generator for outputting at least one reference voltage with a predetermined voltage level after receiving an external voltage; a level shifter for outputting an internal reference voltage with a shifted voltage level by receiving the reference voltage of the reference voltage generator; a driver for outputting an internal voltage by using the internal reference voltage; and a discharging unit for forcibly discharging an over-supplied voltage of the internal voltage by a release pulse signal.

Claims

1. An internal voltage generator, comprising:

a reference voltage generation means for outputting at least one reference voltage with a predetermined voltage level after receiving an external voltage;

a level shifting means for outputting an internal reference voltage with a shifted voltage level by receiving the reference voltage of the reference voltage generation means;

a driving means for outputting an internal voltage by using the internal reference voltage; and

a discharging means to allow discharging an over-supplied voltage of the internal voltage under the control of a release pulse signal whose pulse width is varied according to a voltage level of the over-supplied voltage.

2. The internal voltage generator as recited in claim 1, further comprising a release pulse signal generation means for generating the release pulse signal to control the discharging means.

3. The internal voltage generator as recited in claim 1, wherein the driving means includes:

an active driver for outputting an active internal voltage during an active mode by using the internal reference voltage; and

a standby driver for outputting an standby internal voltage regardless of operation state by using the internal reference voltage.

4. The internal voltage generator as recited in claim 2, wherein the release pulse signal generation means includes:

a pulse enable signal generator for generating a first and a second pulse enable signals using a first reference voltage and a second reference voltage;

a flag signal generator for generating a wide pulse signal or a short pulse signal using the first and the second pulse enable signals; and

a release pulse signal generator for generating the release pulse signal using the wide pulse signal and the short pulse signal.

5. The internal voltage generator as recited in claim 4, wherein the pulse enable signal generator includes:

a first comparator for comparing the internal voltage with the first reference voltage;

a first transfer gate for transferring the output signal of the first comparator, which is controlled by an active enable pulse signal;

a second comparator for comparing the internal voltage with the second reference voltage; and

a second transfer gate for transferring the output signal of the second comparator, which is controlled by the active enable pulse signal.

6. The internal voltage generator as recited in claim 5, wherein the pulse enable signal generator further includes:

a first latching/delaying unit for latching and delaying the transferred signal from the first transfer gate, thereby outputting the first pulse enable signal; and

a second latching/delaying unit for latching and delaying the transferred signal from the second transfer gate, thereby outputting the second pulse enable signal.

7. The internal voltage generator as recited in claim 4, wherein the flag signal generator outputs the wide pulse signal if the internal voltage is higher than the first reference voltage, and outputs the short pulse signal if the internal voltage is between the first reference voltage and the second reference voltage.

8. The internal voltage generator as recited in claim 7, wherein the flag signal generator includes:

a first AND gate for performing a logic AND operation to the first and the second pulse enable signals so as to output the wide pulse signal; and

a second AND gate for performing a logic AND operation to an inverted first pulse enable signal and the second pulse enable signal so as to output the short pulse signal.

9. The internal voltage generator as recited in claim 4, wherein the release pulse signal generator includes:

a first inverter for inverting the active enable pulse signal;

a first delay for delaying the output signal of the first inverter by a first predetermine time;

a second inverter for inverting the output signal of the first delay;

a third AND gate for performing a logic AND operation to the output signal of the first inverter and the output signal of the second inverter;

a fourth AND gate for performing a logic AND operation to the output signal of the third AND gate and the short pulse signal;

a second delay for delaying the output signal of the first inverter by a second predetermined time;

a third inverter for inverting the output signal of the second delay;

a fifth AND gate for performing a logic AND operation to the output of the first inverter and the output of the third inverter;

a sixth AND gate for performing a logic AND operation to the wide pulse signal and the output of the fifth AND gate; and

a NOR gate for performing a logic NOR operation to the output of the fourth AND gate and the output of the sixth AND gate so as to output the release pulse signal.

10. The internal voltage generator as recited in claim 2, wherein the discharging means includes at least one switch.

11. The internal voltage generator as recited in claim 10, wherein the number of switches activated in the discharging means is varied according to the over-supplied voltage of the internal voltage.

12. The internal voltage generator as recited in claim 11, wherein each switch in the discharging means has a same size.

13. The internal voltage generator as recited in claim 12, wherein the release pulse signal generation means includes:

a pulse enable signal generator for generating a first and a second pulse enable signals using a first reference voltage and a second reference voltage;

a flag signal generator for generating a wide pulse or a short pulse signal using the first and the second pulse enable signals; and

a release pulse signal generator for generating the release pulse signal using the wide pulse signal and the short pulse signal.

14. The internal voltage generator as recited in claim 10, wherein a first release pulse signal is applied to said each switch in the discharging means in case that the internal voltage is higher than the first reference voltage, and a second release pulse signal is applied to one of said each switch in case that the internal voltage is between the first reference voltage and the second reference voltage.

15. The internal voltage generator as recited in claim 10, wherein one of the at least one switch in the discharging means is selectively turned on according to the over-supplied voltage.

16. The internal voltage generator as recited in claim 15, wherein each switch in the discharging means has a size different from each other.

17. The internal voltage generator as recited in claim 16, wherein the release pulse signal generator includes:

a pulse enable signal generator for generating a first and a second pulse enable signals using a first reference voltage and a second reference voltage;

a flag signal generator for generating a wide pulse or a short pulse signal using the first and the second pulse enable signals; and

a release pulse signal generator for generating the release pulse signal using the wide pulse signal and the short pulse signal.

18. The internal voltage generator as recited in claim 17, wherein the release pulse generator includes:

a first inverter for inverting the active enable poise signal;

a first delay for delaying the output signal of the first inverter by a first predetermine time;

a second inverter for inverting the output signal of the first delay;

a first AND gate for performing a logic AND operation to the output signal of the first inverter and the output signal of the second inverter,

a second AND gate for performing the output signal of the first AND gate and the short pulse signal; and

a third AND gate for performing a logic AND operation to the output of the front AND gate and the wide pulse signal.

19. A method for controlling an internal voltage generator, comprising the steps of:

a) outputting a reference voltage with a predetermined voltage level by receiving an external voltage;

b) outputting an internal reference voltage with a shifted voltage level by receiving the reference voltage;

c) outputting an internal voltage in an active mode by using the internal reference voltage;

d) outputting an standby internal voltage regardless of an operation state by using the internal reference voltage; and

e) forcibly discharging the internal voltage by using a release pulse signal outputted from a release pulse signal generator, wherein the release pulse signal is outputted when an active enable pulse signal is deactivated.

20. The method as recited in claim 19, wherein a width of the release pulse signal is varied by an over-supplied voltage of the internal voltage.

21. The method as recited in claim 19, wherein number of switch for discharging the internal voltage forcibly is varied by over-supplied voltage of the internal voltage.

22. The method as recited in claim 21, wherein each switch for discharging the internal voltage forcibly has a same size.

23. The method as recited in claim 19, wherein one of switches is selectively turned on according to the over-supplied voltage by means of the release pulse signal.

24. The method as recited in claim 23, wherein each switch for discharging the internal voltage forcibly has a size different from each other.