Drive circuit with low current consumption

• US 6,919,743 B2
• Filed: 01/31/2003
• Issued: 07/19/2005
• Est. Priority Date: 02/20/2002
• Status: Expired due to Term

• Current Assignee: Trivale Technologies, LLC (Vector Capital Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Tobita, Youichi
• Primary Examiner(s): Wells, Kenneth B.
• Application Number:
  US10/355,286
• Publication Number:
  US 20040160258A1
• Time in Patent Office: 900 Days
• Field of Search: 327108-112, 327/333, 326 62- 82
• US Class Current: 327/108
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: H03K 19/0013 in field effect transistor circuits
• CPC Class Codes: H03K 19/018571 of complementary type, e.g. CMOS

Abstract

A drive circuit includes a first level shift circuit outputting a potential higher than an input potential by a prescribed voltage; a pull-up circuit outputting to an output node a potential lower than an output potential of the first level shift circuit by the prescribed voltage; a second level shift circuit outputting a potential lower than the input potential by the prescribed voltage; a pull-down circuit outputting to the output node a potential higher than an output potential of the second level shift circuit by the prescribed voltage; and a capacitor connected between output nodes of the first and second level shift circuits. Accordingly, through-current is reduced.

Claims

1. A drive circuit for outputting to an output node a potential corresponding to an input potential, comprising:

a first level shift circuit outputting a potential produced by level shifting an input potential by a first voltage, in a first potential direction, to produce an output potential of said first level shift circuit, wherein said first level shift circuit includes

a first current limiting element having a first electrode receiving a first power supply potential,

a first transistor of a first conductivity type, having a first electrode receiving a second power supply potential, a second electrode, and an input electrode receiving the input potential, and

second transistor of a second conductivity type, having a first electrode and an input electrode connected to the second electrode of said first current limiting element, and having a second electrode connected to the second electrode of said first transistor; and

a second level shift circuit outputting a potential produced by level shifting the output potential of said first level shift circuit by a second voltage, in a second potential direction, opposite the first potential direction, to an output node, wherein said second level shift circuit includes

a third transistor of the second conductivity type, having a first electrode receiving a third power supply potential, a second electrode, and an input electrode connected to the second electrode of said first current limiting element, and

a fourth transistor of the first conductivity type, having a first electrode connected to the second electrode of said third transistor, and having a second electrode and an input electrode connected to the output node.

2. The drive circuit according to claim 1, wherein said second level shift circuit further includes a second current limiting element connected between said output node and a line of a fourth power supply potential.

3. The drive circuit according to claim 2, wherein

the first and third power supply potentials are the same potential, and

the second and fourth power supply potential are the same potential.

4. The drive circuit according to claim 2, wherein said first and second current limiting elements are first and second resistance elements, respectively.

5. The drive circuit according to claim 2, wherein

said first current limiting element is a fifth transistor of the first conductivity type having an input electrode receiving a first constant voltage, and

said second current limiting element is a sixth transistor of the second conductivity type having an input electrode receiving a second constant voltage.

6. The drive circuit according to claim further comprising a constant voltage generating circuit generating the first and second constant voltages.

7. A drive circuit for outputting to an output node a potential corresponding to an input potential, comprising:

a first level shift circuit outputting a potential produced by level shifting an input potential by a first voltage, in a first potential direction, to produce an output potential of said level shift circuit;

a second level shift circuit outputting a potential produced by level shifting the output potential of said first level shift circuit by a second voltage, in a second potential direction, opposite the first potential direction, to an output node; and

a pulse generating circuit changing potential at a first node between said first and second level shift circuits pulsewise, in the first potential direction, in response to a change of the input potential in the first potential direction.

8. The drive circuit according to claim 7, wherein said pulse generating circuit includes a capacitor having a first electrode connected to the first node, and having a second electrode at which a potential is caused to change pulsewise in the first potential direction in response to a change of the input potential in the first potential direction.

9. The drive circuit according to claim 8, further comprising:

a first transistor of the first conductivity type, having a first electrode receiving a first power supply potential, and having a second electrode connected to the first node; and

a third level shift circuit generating a potential produced by level shifting the input potential by the sum of the first voltage and a threshold voltage of said first transistor in the first potential direction, and transmitting the potential generated to an input electrode of said first transistor.

10. The drive circuit according to claim 7, wherein said pulse generating circuit includes a switching element, having a first electrode receiving a first power supply potential, having a second electrode connected to the first node, and becoming conductive, pulsewise, in response to a change of the input potential in the first potential direction.

11. The drive circuit according to claim 10, wherein said pulse generating circuit further includes a current cut-off circuit preventing current from flowing between the first node and a second node having a second power supply potential when said switching element is conductive.

12. A drive circuit for outputting to an output node a potential corresponding to an input potential, comprising:

a first level shift circuit outputting a potential produced by level shifting an input potential by a first voltage, in a first potential direction, to produce an output potential of said first level shift circuit;

a second level shift circuit outputting a potential produced by level shifting the output potential of said first level shift circuit by a second voltage, in a second potential direction, opposite the first potential direction, to a first node; and

an offset compensation circuit canceling an offset voltage of said drive circuit, wherein said offset compensation circuit includes;

a first capacitor;

a first switching circuit, transmitting the input potential to a first electrode of said first capacitor and connecting a second electrode of said first capacitor to the first node;

a second switching circuit transmitting the input potential to the second electrode of said first capacitor and transmitting a potential at the first electrode of said first capacitor to said first level shift circuit instead of the input potential; and

a third switching circuit transmitting a potential at the first node to the output node.

13. The drive circuit according to claim 12, wherein said offset compensation circuit further includes a pulse generating circuit changing an analog potential at the first node pulsewise, in the second potential direction, opposite to the first potential direction, during a period when the input potential is applied to the first electrode of said first capacitor by said first switching circuit and the second electrode of said first capacitor is connected to the first node.

14. The drive circuit according to claim 13, wherein said pulse generating circuit includes a second capacitor, having a first electrode connected to the first node, and having a second electrode at which a potential is caused to change in the second potential direction, opposite to the first potential direction, at a prescribed timing.

15. The drive circuit according to claim 13, wherein said pulse generating circuit includes a switching element, having a first electrode connected to the first node, having a second electrode receiving a power supply potential, and becoming conductive, pulsewise, at a prescribed timing.

16. The drive circuit according to claim 15, wherein said pulse generating circuit further includes a current limiting circuit limiting an output current of said second level shift circuit when said switching element is conductive.

17. A drive circuit for outputting to an output node a potential corresponding to an input potential, comprising:

a first level shift circuit outputting a potential produced by level shifting an input potential by a first voltage, in a first potential direction, to produce an output potential of said first level shift circuit;

a second level shift circuit outputting a potential produced by level shifting the output potential of said first level shift circuit by a second voltage, in a second potential direction, opposite the first potential direction, to an output node; and

a third level shift circuit outputting a potential produced by level shifting the input potential by the second voltage in the second potential direction; and

a fourth level shift circuit outputting a potential produced by level shifting an output potential of said third level shift circuit by the first voltage, in the first potential direction, to the output node.

18. The drive circuit according to claim 17, further comprising a capacitor, having a first electrode and a second electrode receiving output potential of said first and third level shift circuits, respectively, and adding a change amount of an output potential of one level shift circuit of said first and third level shift circuits to an output potential of the other of said first and third level shift circuits by capacitive coupling.

19. A drive circuit for outputting to an output node a potential corresponding to an input potential, comprising:

a first level shift circuit outputting a potential produced by level shifting an input potential by a first voltage, in a first potential direction, to produce an output potential of said first level shift circuit;

a second level shift circuit outputting a potential produced by level shifting the output potential of said first level shift circuit by a second voltage, in a potential direction opposite the first potential direction, to a first node;

a third level shift circuit outputting a potential produced by level shifting the input potential by a third voltage, in a second potential direction, to produce an output potential of said third level shift circuit;

a fourth level shift circuit outputting a potential produced by level shifting the output potential of said third level shift circuit by a fourth voltage, in a potential direction opposite the second potential direction, to a second node;

a first offset compensation circuit canceling an offset voltage of said first and second level shift circuits; and

a second offset compensation circuit canceling an offset voltage of said third and fourth level shift circuits, wherein

said first offset compensation circuits includes

a first capacitor,

a first switching circuit transmitting the input potential to a first electrode of said first capacitor and connecting a second electrode of said first capacitor to the first node,

a second switching circuit transmitting the input potential to the second electrode of said first level shift circuit instead of transmitting the input potential, and

a third switching circuit transmitting the potential at the first node to the output node, and

said second offset compensation circuit includes

a second capacitor,

a fourth switching circuit transmitting the input potential to a first electrode of said second capacitor and connecting the second electrode of said second capacitor to the second node,

a fifth switching circuit transmitting the input potential to the second electrode of said second capacitor and transmitting the potential at the first electrode of said second capacitor to said third level shift circuit instead of transmitting the input potential, and

a sixth switching circuit transmitting the potential at the second node to the output node.

20. The drive circuit according to claim 19, wherein

said first level shift circuit includes

a first current limiting element having a first electrode receiving a first power supply potential, and

a first transistor of a first conductivity type, having a first electrode connected to a second electrode of said first current limiting element, a second electrode receiving a second power supply potential, and an input electrode receiving the input potential,

said second level shift circuit includes a second transistor of a second conductivity type, having a first electrode receiving a third power supply potential, a second electrode connected to the first node, and an input electrode connected to the second electrode of said first current limiting element,

said third level shift circuit includes

a second current limiting element having a first electrode receiving a fourth power supply potential, and

a third transistor of the second conductivity type having a first electrode connected to a second electrode of said second current limiting element, a second electrode receiving a fifth power supply potential, and an input electrode receiving the input potential, and

said fourth level shift circuit includes a fourth transistor of the first conductivity type, having a first electrode receiving a sixth power supply potential, a second electrode connected to the second node, and an input electrode connected to the second electrode of said second current limiting element.

21. The drive circuit according to claim 20, wherein

said first level shift circuit further includes a fifth transistor of the second conductivity type, having a first electrode and an input electrode connected to the second electrode of said first current limiting element, and a second electrode connected to the first electrode of said first transistor,

said second level shift circuit further includes a sixth transistor of the first conductivity type, having a first electrode connected to the second electrode of said second transistor, and a second electrode and an input electrode connected the first node,

said third level shift circuit further includes a seventh transistor of the first conductivity type, having a first electrode and an input electrode connected to the second electrode of said second current limiting element, and a second electrode connected to the first electrode of said first transistor, and

said fourth level shift circuit further includes an eighth transistor of the second conductivity type, having a first electrode connected to the second electrode of said second transistor, and a second electrode and an input electrode connected to the second node.