Semiconductor device, image display device, storage device, and electronic device

• US 8,773,173 B2
• Filed: 12/13/2012
• Issued: 07/08/2014
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Watanabe, Kazunori
• Primary Examiner(s): Nguyen, Hai L
• Application Number:
  US13/713,323
• Publication Number:
  US 20130162305A1
• Time in Patent Office: 572 Days
• Field of Search: 327/108, 327/112
• US Class Current: 327/108
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: H03K 17/00 Electronic switching or gating, i.e. not by contact-making and –breaking gated amplifiers H03F3/72; switching arrangements for exchange systems using static devices H04Q3/52

Abstract

To provide a semiconductor device with reduced power consumption that includes a selection transistor. To provide a semiconductor device capable of high-speed operation without increasing a power supply potential. A buffer circuit connected to a gate line has a function of generating a potential higher than a high power supply potential by using the high power supply potential and outputs the potential in response to a selection signal. Specifically, a bootstrap circuit boosts a high power supply potential that is input to an inverter that is the closest to an output side in the buffer circuit. Further, the bootstrap circuit boosts the potential when the gate line is selected, and does not boost the potential when the gate line is not selected.

Claims

1. A semiconductor device comprising:

a circuit including a selection transistor; and

a buffer circuit electrically connected to a gate of the selection transistor through a first signal line,

wherein the buffer circuit comprises;

a first inverter and a second inverter that are sequentially connected in series; and

a bootstrap circuit,

wherein an input terminal of the first inverter is electrically connected to an input signal line to which a selection signal is input,

wherein an output terminal of the second inverter is electrically connected to the first signal line,

wherein a high-potential input terminal of the first inverter is electrically connected to a second signal line to which a first potential is input,

wherein low-potential input terminals of the first inverter and the second inverter are electrically connected to a third signal line to which a second potential lower than the first potential is input, and

wherein the bootstrap circuit outputs a third potential higher than the first potential to a high-potential input terminal of the second inverter in response to the selection signal.

2. The semiconductor device according to claim 1,

wherein the bootstrap circuit comprises:

a diode;

a capacitor; and

a third inverter,

wherein an input terminal of the diode is electrically connected to the second signal line, and an output terminal of the diode is electrically connected to the high-potential input terminal of the second inverter,

wherein an input terminal of the third inverter is electrically connected to an output terminal of the first inverter, and

wherein one terminal of the capacitor is electrically connected to the high-potential input terminal of the second inverter, and the other terminal of the capacitor is electrically connected to an output terminal of the third inverter.

3. The semiconductor device according to claim 2,

wherein the ratio of the channel width to the channel length of a transistor included in the first inverter is one eighth that the ratio of the channel width to the channel length of a transistor included in the third inverter.

4. The semiconductor device according to claim 1, wherein the first inverter and the second inverter each include a transistor including an oxide semiconductor film.

5. The semiconductor device according to claim 1,

wherein the ratio of the channel width to the channel length of a transistor included in the first inverter is twice that the ratio of the channel width to the channel length of a transistor included in the second inverter.

6. The semiconductor device according to claim 1, wherein the first inverter and the second inverter each include a CMOS circuit.

7. An electronic device comprising the semiconductor device according to claim 1.

8. A semiconductor device comprising:

a circuit including a selection transistor; and

a buffer circuit electrically connected to a gate of the selection transistor through a first signal line,

wherein the buffer circuit comprises;

a first inverter and a second inverter that are sequentially connected in series; and

a bootstrap circuit,

wherein an input terminal of the first inverter is electrically connected to an input signal line to which a selection signal is input,

wherein an output terminal of the second inverter is electrically connected to the first signal line,

wherein a high-potential input terminal of the first inverter and an input terminal of the bootstrap circuit are electrically connected to a second signal line to which a first potential is input,

wherein low-potential input terminals of the first inverter and the second inverter are electrically connected to a third signal line to which a second potential lower than the first potential is input,

wherein an output terminal of the bootstrap circuit is electrically connected to a high-potential input terminal of the second inverter, and

wherein the bootstrap circuit boosts the first potential when the selection signal is input to the buffer circuit.

9. The semiconductor device according to claim 8,

wherein the bootstrap circuit comprises:

a diode;

a capacitor; and

a third inverter,

wherein an input terminal of the diode is electrically connected to the second signal line, and an output terminal of the diode is electrically connected to the high-potential input terminal of the second inverter,

wherein an input terminal of the third inverter is electrically connected to an output terminal of the first inverter, and

wherein one terminal of the capacitor is electrically connected to the high-potential input terminal of the second inverter, and the other terminal of the capacitor is electrically connected to an output terminal of the third inverter.

10. The semiconductor device according to claim 9,

wherein the ratio of the channel width to the channel length of a transistor included in the first inverter is one eighth that the ratio of the channel width to the channel length of a transistor included in the third inverter.

11. The semiconductor device according to claim 8, wherein the first inverter and the second inverter each include a transistor including an oxide semiconductor film.

12. The semiconductor device according to claim 8,

wherein the ratio of the channel width to the channel length of a transistor included in the first inverter is twice that the ratio of the channel width to the channel length of a transistor included in the second inverter.

13. The semiconductor device according to claim 8, wherein the first inverter and the second inverter each include a CMOS circuit.

14. An electronic device comprising the semiconductor device according to claim 8.

15. A semiconductor device comprising:

a circuit including a selection transistor; and

a buffer circuit electrically connected to a gate of the selection transistor through a first signal line,

wherein the buffer circuit comprises;

first to n-th inverters that are sequentially connected in series; and

a bootstrap circuit,

wherein an input terminal of the first inverter is electrically connected to an input signal line to which a selection signal is input,

wherein an output terminal of the n-th inverter is electrically connected to the first signal line,

wherein high-potential input terminals of the first to (n−

1) th inverters are electrically connected to a second signal line to which a first potential is input,

wherein low-potential input terminals of the first to n-th inverters are electrically connected to a third signal line to which a second potential lower than the first potential is input, and

wherein the bootstrap circuit outputs a third potential higher than the first potential to a high-potential input terminal of the n-th inverter in response to the selection signal.

16. The semiconductor device according to claim 15,

wherein the bootstrap circuit comprises:

a diode;

a capacitor; and

an (n+1)-th inverter,

wherein an input terminal of the diode is electrically connected to the second signal line, and an output terminal of the diode is electrically connected to the high-potential input terminal of the n-th inverter,

wherein an input terminal of the (n+1)-th inverter is electrically connected to an output terminal of the (n−

1)-th inverter, and

wherein one terminal of the capacitor is electrically connected to the high-potential input terminal of the n-th inverter, and the other terminal of the capacitor is electrically connected to an output terminal of the (n+1)-th inverter.

17. The semiconductor device according to claim 15, wherein the first to n-th inverters each include a CMOS circuit.

18. The semiconductor device according to claim 15, wherein the first to n-th inverters each include a transistor including an oxide semiconductor film.

19. An electronic device comprising the semiconductor device according to claim 15.

20. The semiconductor device according to claim 15, wherein n is an even number.