Semiconductor device and driving method thereof

• US 8,238,476 B2
• Filed: 01/20/2011
• Issued: 08/07/2012
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kato, Kiyoshi, Shionoiri, Yutaka
• Primary Examiner(s): Nguyen, Khanh V
• Application Number:
  US13/010,209
• Publication Number:
  US 20110111721A1
• Time in Patent Office: 565 Days
• Field of Search: 330/277, 330/253, 330/255, 375/316
• US Class Current: 375/316
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1266 the substrate on which the devices are formed not being the final device substrate, e.g. using a temporary substrate
• CPC Class Codes: H01L 27/13 combined with thin-film or thick-film passive components

Abstract

The invention provides a semiconductor device with high yield by reducing an effect of variations in characteristics of a semiconductor element. Further, by reducing an effect of variations in characteristics of a semiconductor element to improve productivity, an inexpensive semiconductor device can be provided. Further, an inexpensive semiconductor device can be provided by forming a semiconductor device in a large amount over a large substrate such as a glass substrate and a flexible substrate. A semiconductor device of the invention includes a demodulation signal generating circuit and an antenna or a wire for connecting the antenna. The demodulation signal generating circuit includes a demodulation circuit and a correction circuit. The correction circuit corrects a first demodulation signal generated from the demodulation circuit and generates a second demodulation signal.

Claims

1. A semiconductor device comprising:

a demodulation circuit for demodulating an alternating signal and generating a first demodulation signal; and

an amplifier comprising;

a first line;

a second line; and

a first transistor and a second transistor which are connected to each other in series and electrically interposed between the first line and the second line,

wherein the first transistor and the second transistor are arranged so that, when the first line and the second line are respectively applied with a first power source voltage and a second power source voltage, a changing point of input-output characteristics of the amplifier is located at a voltage lower than a half value of a difference between the first power source voltage and the second power source voltage,

wherein the first demodulation signal is input to gates of the first transistor and the second transistor of the amplifier,

wherein the amplifier generates and outputs a second demodulation signal, and

wherein an amplitude of the second demodulation signal is equal to either an amplitude of the first power source voltage or an amplitude of the second power source voltage.

2. The semiconductor device according to claim 1,

wherein the first transistor and the second transistor are a P-channel transistor and an N-channel transistor, respectively, and

wherein a width of a channel of the second transistor is greater than a width of a channel of the first transistor.

3. The semiconductor device according to claim 1,

wherein the first transistor and the second transistor are a P-channel transistor and an N-channel transistor, respectively, and

wherein a length of a channel of the first transistor is greater than a length of a channel of the second transistor.

4. The semiconductor device according to claim 1,

wherein the first transistor and the second transistor are a P-channel transistor and an N-channel transistor, respectively, and

wherein an absolute value of a threshold voltage of the first transistor is greater than an absolute value of a threshold voltage of the second transistor.

5. The semiconductor device according to claim 1, wherein the changing point of input-output characteristics of the amplifier is located within a range of 25 to 45% of the first power source voltage.

6. The semiconductor device according to claim 1, further comprising a differential amplifier,

wherein an input terminal of the differential amplifier is electrically connected to an output terminal of the demodulation circuit, and

wherein an output terminal of the differential amplifier is electrically connected to an input terminal of the amplifier.

7. The semiconductor device according to claim 1, further comprising:

at least one of a power source circuit, a clock generating circuit, a memory, a memory control circuit, and a modulation circuit.

8. A semiconductor device comprising:

a demodulation circuit for demodulating an alternating signal and generating a first demodulation signal; and

an amplifier comprising;

a first line;

a second line; and

a first transistor and a second transistor which are connected to each other in series and electrically interposed between the first line and the second line,

wherein the first transistor and the second transistor are arranged so that, when the first line and the second line are respectively applied with a first power source voltage and a second power source voltage, a changing point of input-output characteristics of the amplifier is located at a voltage higher than a half value of a difference between the first power source voltage and the second power source voltage,

wherein the first demodulation signal is input to gates of the first transistor and the second transistor of the amplifier,

wherein the amplifier generates and outputs a second demodulation signal,

wherein an amplitude of the second demodulation signal is equal to either an amplitude of the first power source voltage or an amplitude of the second power source voltage.

9. The semiconductor device according to claim 8,

wherein the first transistor and the second transistor are a P-channel transistor and an N-channel transistor, respectively, and

wherein a width of a channel of the second transistor is smaller than a width of a channel of the first transistor.

10. The semiconductor device according to claim 8,

wherein the first transistor and the second transistor are a P-channel transistor and an N-channel transistor, respectively, and

wherein a length of a channel of the first transistor is smaller than a length of a channel of the second transistor.

11. The semiconductor device according to claim 8,

wherein the first transistor and the second transistor are a P-channel transistor and an N-channel transistor, respectively, and

wherein an absolute value of a threshold voltage of the first transistor is smaller than an absolute value of a threshold voltage of the second transistor.

12. The semiconductor device according to claim 8, wherein the changing point of input-output characteristics of the amplifier is located within a range of 55 to 75% of the first power source voltage.

13. The semiconductor device according to claim 8, further comprising a differential amplifier,

wherein an input terminal of the differential amplifier is electrically connected to an output terminal of the demodulation circuit, and

wherein an output terminal of the differential amplifier is electrically connected to an input terminal of the amplifier.

14. The semiconductor device according to claim 8, further comprising:

at least one of a power source circuit, a clock generating circuit, a memory, a memory control circuit, and a modulation circuit.