Semiconductor memory device, and method of controlling the same

• US 7,688,661 B2
• Filed: 09/22/2008
• Issued: 03/30/2010
• Est. Priority Date: 11/09/1999
• Status: Expired due to Fees

• Current Assignee: Socionext Inc.
• Original Assignee: Fujitsu Microelectronics Limited (Fujitsu Limited)
• Inventors: Fujioka, Shinya, Sato, Kotoku, Nishimura, Koichi, Kawakubo, Tomohiro
• Primary Examiner(s): Phan; Trong
• Application Number:
  US12/234,969
• Publication Number:
  US 20090016142A1
• Time in Patent Office: 554 Days
• Field of Search: 365/222, 365/226, 365/227, 365/228, 365/229, 327/544
• US Class Current: 365/222
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3234 Power saving characterised by the action undertaken
• CPC Class Codes: G06F 1/3268 Power saving in hard disk drive
• CPC Class Codes: G06F 1/3275 Power saving in memory, e.g. RAM, cache
• CPC Class Codes: G11C 11/406 Management or control of the refreshing or charge-regeneration cycles
• CPC Class Codes: G11C 11/40615 Internal triggering or timing of refresh, e.g. hidden refresh, self refresh, pseudo-SRAMs
• CPC Class Codes: G11C 14/00 Digital stores characterised by arrangements of cells having volatile and non-volatile storage properties for back-up when the power is down
• CPC Class Codes: G11C 2207/2227 Standby or low power modes
• CPC Class Codes: G11C 2211/4067 Refresh in standby or low power modes
• CPC Class Codes: G11C 5/14 Power supply arrangements , e.g. power down, chip selection or deselection, layout of wirings or power grids, or multiple supply levels
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence
• 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
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

An internal voltage generator when activated, generates an internal voltage to be supplied to an internal circuit. Operating the internal voltage generator consumes a predetermined amount of the power. In response to a control signal from the exterior, an entry circuit inactivates the internal voltage generator. When the internal voltage generator is inactivated, the internal voltage is not generated, thereby reducing the power consumption. By the control signal from the exterior, therefore, a chip can easily enter a low power consumption mode. The internal voltage generator is exemplified by a booster for generating the boost voltage of a word line connected with memory cells, a substrate voltage generator for generating a substrate voltage, or a precharging voltage generator for generating the precharging voltage of bit lines to be connected with the memory cells.

Claims

1. A semiconductor device comprising:

a memory core with a plurality of memory cells;

an internal voltage generator, coupled to the memory core via an internal power supply line, that generates a boosted internal voltage based on an external voltage and supplies the boosted internal voltage to the memory core via the internal power supply line;

a command decoder that receives a plurality of control signals and generates an internal command signal; and

a low power entry circuit, coupled to the command decoder, that receives at least one of the plurality of control signals and generates a low power signal indicating a low power consumption mode where a refresh operation is prohibited,

wherein the internal voltage generator stops supplying the internal voltage to the internal power supply line in response to the low power signal while the external voltage is supplied to the semiconductor device, and

wherein the internal voltage generator includes a reference voltage generator, a detector and a booster circuit.

2. The semiconductor device according to claim 1, wherein:

the reference voltage generator generates a reference voltage, the detector, coupled to the reference voltage generator, compares the internal voltage with the reference voltage and outputs a compared signal, and the booster circuit, coupled to the detector, do pumping operations in response to the compared signal.

3. The semiconductor device according to claim 1, wherein the reference voltage generator decreases a level of the reference voltage in response to the low power signal.

4. The semiconductor device according to claim 1, wherein the detector includes a circuit, coupled to the low power entry circuit, whose operation is stopped in response to the low power signal.

5. The semiconductor device according to claim 1, wherein the booster circuit includes a plurality of booster units that are inactivated in response to the low power signal.

6. The semiconductor device according to claim 1, wherein the external voltage is supplied to the internal power supply line in the low power consumption mode.

7. A semiconductor device comprising:

a memory core with a plurality of memory cells;

an internal voltage generator, coupled to the memory core via an internal power supply line, that generates a boosted internal voltage based on an external voltage and supplies the boosted internal voltage the memory core via the internal power supply line;

a command decoder that receives a plurality of control signals and generates an internal command signal; and

a low power entry circuit, coupled to the command decoder, that receives at least on of the plurality of control signals and generates a low power signal indicating a low power consumption mode where a refresh operation is prohibited,

wherein the internal voltage generator includes a plurality of booster circuits, coupled to the low power entry circuit, and at least one of the plurality of booster circuits is inactivated in response to the low power signal, and

wherein the internal voltage generator includes a reference voltage generator and a detector.

8. The semiconductor device according to claim 7, wherein:

the reference voltage generator generates a reference voltage, the detector, coupled to the reference voltage generator, compares the internal voltage with the reference voltage and outputs a compared signal, and the plurality of booster circuits, coupled to the detector, do pumping operations in response to the compared signal.

9. The semiconductor device according to claim 7, wherein the reference voltage generator decreases a level of the reference voltage in response to the low power signal.

10. A semiconductor device comprising:

a memory core with a plurality of memory cells;

an internal voltage generator, coupled to the memory core via an internal power supply line, that generates a boosted internal voltage based on an external voltage and supplies the boosted internal voltage to the memory core via the internal power supply line in a normal mode;

a command decoder that receives a plurality of control signals and generates an internal command signal; and

a low power entry circuit, coupled to the command decoder, that receives at least one of the plurality of control signals and generates a low power signal indicating a low power consumption mode where a refresh operation is prohibited,

wherein a voltage, which is lower than the boosted internal voltage, is supplied to the internal power supply line in the low power consumption mode, and

wherein the internal voltage generator includes a reference voltage generator and a detector.

11. A semiconductor device comprising:

a memory core including a plurality of memory cells;

an internal voltage generator, coupled to the memory core via an internal power supply line, that generates an internal voltage based on an external voltage and supplies the internal voltage to the memory core via the internal power supply line;

a command decoder that receives a plurality of control signals and generates an internal command signal; and

a low power entry circuit, coupled to the command decoder, that receives at least one of the plurality of control signals and generates a low power signal indicating a low power consumption mode where a refresh operation is prohibited,

wherein the internal voltage generator stops supplying the internal voltage to the internal power supply line in response to the low power signal while the external voltage is supplied to the semiconductor device, and

wherein the internal voltage generator includes a reference voltage generator, a comparator, a compensating circuit and a regulator.

12. The semiconductor device according to claim 11, wherein:

the reference voltage generator generates a reference voltage, the comparator, coupled to the reference voltage generator, compares an output of the compensating circuit with the reference voltage and supplies a voltage to the regulator, and the regulator, coupled to the comparator, outputs the internal voltage in response to the voltage.

13. The semiconductor device according to claim 11, wherein the reference voltage generator decreases a level of the reference voltage in response to the low power signal.

14. The semiconductor device according to claim 11, wherein the internal power supply line is disconnected to the regulator based on the low power signal.

15. The semiconductor device according to claim 11, wherein the external voltage is supplied to the internal power supply line in the low power consumption mode.

16. A semiconductor device provided on a substrate comprising:

an internal voltage generator that generates an internal voltage based on an external voltage and supplies the internal voltage to the substrate via an internal power supply line;

a command decoder that receives a plurality of control signals and generates an internal command signal; and

a low power entry circuit, coupled to the command decoder, that receives at least one of the plurality of control signals and generates a low power signal indicating a low power consumption mode where a refresh operation is prohibited,

wherein the internal voltage generator stops supplying the internal voltage to the internal power supply line in response to the low power signal while the external voltage is supplied to the semiconductor device, and

wherein the internal voltage generator includes an oscillator and a pumping circuit.

17. The semiconductor device according to claim 16, further comprising:

a detector that detects a level of the internal voltage and outputs a detected signal; and

a plurality of pumping circuits, coupled to the detector, that do pumping operations in response to the detected signal.

18. The semiconductor device according to claim 16, wherein the detector includes a circuit, coupled to the low power entry circuit, whose operation is stopped in response to the low power signal.

19. The semiconductor device according to claim 17, wherein at least one of the plurality of pumping circuits are inactivated in response to the low power signal.

20. The semiconductor device according to claim 16, wherein the external power voltage is supplied to the internal power supply line in the low power consumption mode.

21. A semiconductor device comprising:

a bit line coupled to a memory cell;

an internal voltage generator that generates an internal voltage based on an external voltage and supplies the internal voltage to precharge the bit line;

a command decoder that receives a plurality of control signals and generates an internal command signal; and

a low power entry circuit, coupled to the command decoder, that receives at least one of the plurality of control signals and generates a low power signal indicating a low power consumption mode where a refresh operation is prohibited,

wherein the internal voltage generator, coupled to the low power entry circuit, stops supplying the internal voltage to the internal power supply line in response to the low power signal while the external voltage is supplied to the semiconductor device, and

wherein the internal voltage generator includes a reference voltage generator and a comparator.

22. The semiconductor device according to claim 21, further comprising:

a reference voltage generator that generates a reference voltage;

a plurality of comparators, coupled to the reference voltage generator, that compare the internal voltage with the reference voltage and output a compared signals; and

a generator, coupled to at least one of the plurality of comparators, that receives the compared signals and generates the internal voltage.

23. The semiconductor device according to claim 21, wherein the reference voltage generator decreases a level of a reference voltage in response to the low power signal.

24. The semiconductor device according to claim 22, wherein the comparator includes a plurality of units and at least one of the plurality of units is inactivated in response to the low power signal.

25. The semiconductor device according to claim 21, wherein the external voltage is supplied to the internal power supply line in the low power consumption mode.