Granted Patent B2

US 8,134,858 · App. 12/648,084 · Granted Mar 13, 2012

Abstract

Claims (38)

1. A semiconductor device comprising an internal voltage generator circuit said internal voltage generator circuit comprising:

a first transistor having a first and a second main electrode and a control electrode;

a control circuit controlling a voltage between said second main electrode and said control electrode of said first transistor such that a voltage at said first main electrode of said first transistor remains at a predetermined voltage;

a second transistor having a first and a second main electrode and a control electrode, a voltage between said second main electrode and said control electrode of said first transistor being applied to between said second main electrode and said control electrode of said second transistor;

a load circuit connected to said first main electrode of said second transistor, wherein said second transistor is larger in current supply capability than said first transistor; and

a switch disposed between said first main electrode of said second transistor and said load circuit,

wherein a first and a second internal voltage generator circuits are provided as two of said internal voltage generator circuits, each of said first and said second internal voltage generator circuits having a variable resistor connected to said first main electrode of said first transistor,

said load circuit is a storage element storing information corresponding to a High level or a Low level, and

said variable resistor included in said first internal voltage generator circuit has a resistance value previously set such that said information corresponding to said High level can be stored in said storage element, and said variable resistor included in said second internal voltage generator circuit has a resistance value previously set such that said information corresponding to said Low level can be stored in said storage element.

2. The semiconductor device according to claim 1 , further comprising a bit line control circuit receiving an arbitrary command from outside,

wherein said first internal voltage generator circuit includes a reset control transistor, as a first switch, having a second main electrode connected to said first main electrode of said second transistor included in said first internal voltage generator circuit, a first main electrode connected to said storage element, and a control electrode connected to said bit line control circuit,

said second internal voltage generator circuit includes a set control transistor, as a second switch, having a second main electrode connected to said first main electrode of said second transistor included in said second internal voltage generator circuit, a first main electrode connected to said storage element, and a control electrode connected to said bit line control circuit,

said bit line control circuit applies a reset operation voltage to said control electrode of said reset control transistor upon receipt of an write command from outside for instructing a write operation of said information corresponding to said High level into said storage element, and applies a set operation voltage to said control electrode of said set control transistor upon receipt of a write command from outside for instructing a write operation of said information corresponding to Low level into said storage element,

said reset control transistor, when applied with said reset operation voltage, reduces a voltage applied to said second main electrode of said second transistor included in said first internal voltage generator circuit in accordance with a voltage biased between said second main electrode and said control electrode of said second transistor to generate a first write voltage, and applies said first write voltage to said storage element, and

said set control transistor, when applied with said set operation voltage, reduces a voltage applied to said second main electrode of said second transistor included in said second internal voltage generator circuit in accordance with a voltage biased between said second main electrode and said control electrode of said second transistor to generate a second write voltage, and applies said second write voltage to said storage element.

3. The semiconductor device according to claim 1 , wherein a first voltage at said first main electrode of said first transistor included in said first internal voltage generator circuit, said first voltage being maintained by said control circuit included in said first internal voltage generator circuit, is higher than a second voltage at said first main electrode of said first transistor included in said second internal voltage generator circuit, said second voltage being maintained by said control circuit included in said second internal voltage generator circuit.

4. The semiconductor device according to claim 2 , wherein a first voltage at said first main electrode of said first transistor included in said first internal voltage generator circuit, said first voltage being maintained by said control circuit included in said first internal voltage generator circuit, is higher than a second voltage at said first main electrode of said first transistor included in said second internal voltage generator circuit, said second voltage being maintained by said control circuit included in said second internal voltage generator circuit.

5. A semiconductor device comprising;

a first terminal;

a first internal voltage generator circuit which comprises a first transistor including a first control electrode and first and second main electrodes, a first control circuit controlling a first bias voltage across the first control electrode and the first main electrode of the first transistor such that the second main electrode of the first transistor maintains a first reference voltage, and a second transistor including a second control electrode and a third main electrode controlled by the first bias voltage thereacross and a fourth electrode from which a first internal voltage is derived;

a second internal voltage generator circuit which comprises a third transistor including a third control electrode and fifth and sixth main electrodes, a second control circuit controlling a second bias voltage across the third control electrode and the fifth main electrode of the third transistor such that the sixth main electrode of the third transistor maintains a second reference voltage, and a fourth transistor including fourth control electrode and a seventh main electrode controlled by the second bias voltage thereacross and an eighth electrode from which a second internal voltage is derived;

a first switch provided between the first terminal and the first internal voltage generator circuit to control supplying the first terminal with the first internal voltage;

a second switch provided between the first terminal and the second internal voltage generator circuit to control supplying the first terminal with the second internal voltage; and

a memory element electrically connected to the first terminal, the memory element being capable of storing either one of reset data and set data, wherein a potential of the first internal voltage is related to the reset data, and a potential of the second internal voltage is related to the set data.

6. The semiconductor device according to claim 5 , further comprising a control circuit controlling the first and second switches such that the first switch is shorter in activated period than the second switch.

7. The semiconductor device as claimed in claim 5 , wherein the memory element changes to be a reset state when supplied with the first internal voltage, changing to be a set state when supplied with the second internal voltage, and the reset state being different in resistance value from the set state.

8. The semiconductor device as claimed in claim 7 , wherein the reset state is greater in resistance value than the set state.

9. A semiconductor device comprising:

a terminal;

a first internal voltage generator which comprises a first transistor including a first control electrode and first and second main electrodes, a first control circuit controlling a first bias voltage across the first control electrode and the first main electrode of the first transistor such that the second main electrode of the first transistor maintains a first reference voltage, and a second transistor including a second control electrode and a third main electrode controlled by the first bias voltage thereacross and a fourth main electrode from which a first internal voltage is derived;

a second internal voltage generator which comprises a third transistor including a third control electrode and fifth and sixth main electrodes, a second control circuit controlling a second bias voltage across the third control electrode and the fifth main electrode of the third transistor such that the sixth main electrode of the third transistor maintains a second reference voltage which is different from the first reference voltage, and a fourth transistor including fourth control electrode and a seventh main electrode controlled by the second bias voltage thereacross and an eight main electrode from which a second internal voltage is derived, the second internal voltage being different from the first internal voltage;

a first switch provided to control supplying the terminal with the first internal voltage; and

a second switch provided to control supplying the terminal with the second internal voltage.

10. The semiconductor device according to claim 9 , further comprising a memory element coupled to the terminal.

11. The semiconductor device according to claim 10 , wherein the memory element changes to be a reset state when supplied with the first internal voltage, changing to be a set state when supplied with the second internal voltage, and the reset state being different in resistance value from the set state.

12. The semiconductor device as claimed in claim 11 , wherein the reset state is greater in resistance value than the set state.

13. The semiconductor device as claimed in claim 9 , further comprising a control circuit controlling the first and second switches such that the first switch is shorter in activated period than the second switch.

14. The semiconductor device as claimed in claim 9 , wherein the first switch is provided between the first internal voltage generator and the terminal and the second switch is provided between the second internal voltage generator and the terminal.

Assignments (8)