SEMICONDUCTOR DEVICE

• US 20100066325A1
• Filed: 09/03/2009
• Published: 03/18/2010
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: SHIONOIRI, Yutaka
• Granted Patent: US 8,284,579 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• 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: H02M 1/126 using passive filters
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The adverse effect of noise a constant voltage receives in a semiconductor device capable of data communication through wireless communication is suppressed. Further, communication is performed normally with a constant voltage with less noise even in the case where the amount of received power is large. The semiconductor device includes an input circuit for generating a DC voltage from an AC signal, a circuit for generating a constant voltage lower than the DC voltage, a circuit portion supplied with the constant voltage, a filter, and a feedback circuit for changing impedance with the constant voltage input from the circuit for generating a constant voltage, wherein the filter is electrically connected between the input circuit and the circuit for generating a constant voltage.

Claims

1. A semiconductor device comprising:

an input circuit;

a circuit configured to generate a constant voltage;

a circuit portion;

a filter electrically connected between the input circuit and an input of the circuit configured to generate the constant voltage; and

a feedback circuit configured to change impedance of the semiconductor device,

wherein an output of the circuit configured to generate the constant voltage is electrically connected to the feedback circuit and an input of the circuit portion.

2. The semiconductor device according to claim 1,

wherein the filter comprises a resistor and a capacitor,

wherein a terminal of the resistor is electrically connected to a terminal of the capacitor and the input of the circuit configured to generate the constant voltage, and another terminal of the resistor is electrically connected to an output of the input circuit, and

wherein another terminal of the capacitor is electrically connected to the feedback circuit.

3. The semiconductor device according to claim 1,

wherein the filter comprises an inductor and a capacitor,

wherein a terminal of the inductor is electrically connected to a terminal of the capacitor and the input of the circuit configured to generate the constant voltage, and another terminal of the inductor is electrically connected to an output of the input circuit, and

wherein another terminal of the capacitor is electrically connected to the feedback circuit.

4. The semiconductor device according to claim 1,

wherein the feedback circuit comprises a resistor and a transistor

wherein one of a source or a drain of the transistor is electrically connected to a terminal of the resistor and the other of the source or the drain of the transistor is electrically connected to the filter,

wherein a gate of the transistor is electrically connected to the output of the circuit configured to generate the constant voltage, and

wherein another terminal of the resistor is electrically connected to the input circuit.

5. The semiconductor device according to claim 1,

wherein the feedback circuit comprises a capacitor and a transistor

wherein one of a source or a drain of the transistor is electrically connected to a terminal of the capacitor and the other of the source or the drain of the transistor is electrically connected to the filter,

wherein a gate of the transistor is electrically connected to an output of the circuit configured to generate the constant voltage,

wherein another terminal of the capacitor is electrically connected to the input circuit.

6. The semiconductor device according to claim 1,

wherein the feedback circuit comprises a diode and a transistor

wherein one of a source or a drain of the transistor is electrically connected to a terminal of the diode and the other of the source or the drain of the transistor is electrically connected to the filter, and

wherein a gate of the transistor is electrically connected to an output of the circuit configured to generate the constant voltage, and

wherein another terminal of the diode is electrically connected to the input circuit.

7. A semiconductor device comprising:

an antenna;

an input circuit electrically connected to the antenna;

a circuit configured to generate a constant voltage;

a circuit portion;

a filter electrically connected between the input circuit and an input of the circuit configured to generate the constant voltage; and

a feedback circuit configured to change impedance of the semiconductor device,

wherein an output of the circuit configured to generate the constant voltage is electrically connected to the feedback circuit and an input of the circuit portion.

8. The semiconductor device according to claim 7,

wherein the filter comprises a resistor and a capacitor,

wherein a terminal of the resistor is electrically connected to a terminal of the capacitor and the input of the circuit configured to generate the constant voltage, and another terminal of the resistor is electrically connected to an output of the input circuit, and

wherein another terminal of the capacitor is electrically connected to the feedback circuit.

9. The semiconductor device according to claim 7,

wherein the filter comprises an inductor and a capacitor,

wherein a terminal of the inductor is electrically connected to a terminal of the capacitor and the input of the circuit configured to generate the constant voltage, and another terminal of the inductor is electrically connected to an output of the input circuit, and

wherein another terminal of the capacitor is electrically connected to the feedback circuit.

10. The semiconductor device according to claim 7,

wherein the feedback circuit comprises a resistor and a transistor

wherein one of a source or a drain of the transistor is electrically connected to a terminal of the resistor and the other of the source or the drain of the transistor is electrically connected to the filter,

wherein a gate of the transistor is electrically connected to the output of the circuit configured to generate the constant voltage, and

wherein another terminal of the resistor is electrically connected to the input circuit.

11. The semiconductor device according to claim 7,

wherein the feedback circuit comprises a capacitor and a transistor

wherein one of a source or a drain of the transistor is electrically connected to a terminal of the capacitor and the other of the source or the drain of the transistor is electrically connected to the filter,

wherein a gate of the transistor is electrically connected to an output of the circuit configured to generate the constant voltage,

wherein another terminal of the capacitor is electrically connected to the input circuit.

12. The semiconductor device according to claim 7,

wherein the feedback circuit comprises a diode and a transistor

wherein one of a source or a drain of the transistor is electrically connected to a terminal of the diode and the other of the source or the drain of the transistor is electrically connected to the filter, and

wherein a gate of the transistor is electrically connected to an output of the circuit configured to generate the constant voltage, and

wherein another terminal of the diode is electrically connected to the input circuit.