Semiconductor Device

• US 20090085638A1
• Filed: 05/25/2006
• Published: 04/02/2009
• Est. Priority Date: 05/27/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Shionoiri, Yutaka, Matsuzaki, Takanori
• Granted Patent: US 7,978,787 B2
• Time in Patent Office: Days
• US Class Current: 327/333
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• 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
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate

Abstract

It is an object of the present invention to prevent an error or malfunction such as nonresponse which is caused due to difference in pulse width in a semiconductor device capable of communicating data wirelessly. In a semiconductor device, a level shift circuit is provided between a data demodulation circuit and each circuit block where demodulated signals are outputted from the data demodulation circuit. In such a manner, voltage amplitude of the demodulated signal is made almost equal to that of the outputted signals from each circuit block. Accordingly, a pulse width of the demodulated signal is made almost equal to that of signals in each circuit block, or a pulse width of the demodulated signal is made almost equal to that of the outputted signals from each circuit block. Accordingly, it is possible to prevent an error or malfunction such as nonresponse which is caused due to difference in pulse width.

Claims

1. A semiconductor device comprising:

a data demodulation circuit in which a wireless signal is demodulated;

a level shift circuit in which an outputted signal of the data demodulation circuit is inputted; and

a control circuit in which an output of the level shift circuit is inputted,

wherein the level shift circuit is supplied with a first DC power supply voltage and a second DC power supply voltage, a voltage amplitude of the second DC power supply voltage is lower than that of the first DC power supply voltage,

wherein the control circuit is supplied with the second DC power supply voltage, and

wherein the level shift circuit outputs a signal having the same voltage amplitude as that of the second DC power supply voltage, which is converted from an inputted signal having the same voltage amplitude as that of the first DC power supply voltage.

4. A semiconductor device according to any one of claims 1 to 3, wherein the control circuit is a circuit for analyzing a signal which is obtained by demodulating the wireless signal.

5. A semiconductor device according to any one of claims 1 to 3, wherein a pulse width of the outputted signal of the data demodulation circuit is the same as that of the outputted signal of the level shift circuit.

2. A semiconductor device comprising:

an antenna capable of communicating data wirelessly;

a data demodulation circuit in which a wireless signal is demodulated;

a level shift circuit in which an outputted signal of the data demodulation circuit is inputted; and

a control circuit in which an output of the level shift circuit is inputted,

wherein the level shift circuit is supplied with a first DC power supply voltage and a second DC power supply voltage, a voltage amplitude of the second DC power supply voltage is lower than that of the first DC power supply voltage,

wherein the control circuit is supplied with the second DC power supply voltage, and

wherein the level shift circuit outputs a signal having the same voltage amplitude as that of the second DC power supply voltage, which is converted from an inputted signal having the same voltage amplitude as that of the first DC power supply voltage.

3. A semiconductor device comprising:

an antenna capable of communicating data wirelessly;

a data demodulation circuit in which a wireless signal is demodulated;

a power supply circuit for generating a first DC power supply voltage and a second DC power supply voltage, a voltage amplitude of the second DC power supply voltage is lower than that of the first DC power supply voltage from the wireless signal;

a level shift circuit in which an outputted signal of the data demodulation circuit is inputted; and

a control circuit in which an output of the level shift circuit is inputted,

wherein the level shift circuit is supplied with the first DC power supply voltage and the second DC power supply voltage,

wherein the control circuit is supplied with the second DC power supply voltage, and

wherein the level shift circuit outputs a signal having the same voltage amplitude as that of the second DC power supply voltage, which is converted from an inputted signal having the same voltage amplitude as that of the first DC power supply voltage.

6. A semiconductor device comprising:

an antenna;

a data demodulation circuit operationally connected with the antenna and for demodulating a wireless signal from the antenna;

a level shift circuit operationally connected with the data demodulation circuit;

a control circuit operationally connected with the level shift circuit; and

a power supply circuit for connecting at least the level shift circuit and the control circuit.