Abstract:
PROBLEM TO BE SOLVED: To provide a noncontact IC card which causes malfunction even if modulation degree of a modulation circuit is increased by preventing interference of a circuit including the modulation circuit on a circuit including a decoding circuit and a clock generation circuit. SOLUTION: The communication device comprises an antenna circuit 2 including a coil, the circuit 3 including the decoding circuit and the clock generation circuit, connected to the antenna circuit 2, and the circuit including the modulation circuit connected to the antenna circuit 2 through a wire of a system different from that of the circuit 3 including the decoding circuit and the clock generation circuit. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a demodulation circuit capable of stably demodulating an ASK signal having a small modulation rate with a circuit of comparatively simple configuration. SOLUTION: One part of the ASK signal including any one of an upper envelope and a lower envelope is amplified in an amplifier 101. Then, the signal component of the envelope of the ASK signal included in the amplified signal is extracted in a signal extractor 110. Since the envelope of the ASK signal is equivalent to a baseband signal, the component of the baseband signal is amplified in the amplifier 101, and the component of the amplified baseband signal is extracted in the signal extractor 110. Accordingly, since the baseband signal having a large amplitude can be extracted by amplifying the minute baseband signal included in the ASK signal, the ASK signal having a small modulation rate can be stably demodulated. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a communication apparatus including a circuit for receiving a radio wave and a circuit for transmitting a radio wave, wherein the circuit for transmitting the radio wave can transmit the radio wave with sufficient strength and the circuit for receiving the radio wave can obtain sufficient sensitivity even if both the circuits share an antenna circuit. SOLUTION: The communication apparatus includes: the antenna circuit 2 including a first coil; a first circuit 3 using the first coil of the antenna circuit 2; and a second circuit 4 using a second coil being part of the first coil which is shared with the circuit 2 so that the impedance of the second coil is smaller than that of the first coil. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a semiconductor rectifying element, which can prevent a reverse withstand voltage from dropping accompanying higher impurity density of a well, and its manufacturing method, and a rectifying circuit for the power source of a contactless IC card. SOLUTION: An area Anw2 into which n type impurities are introduced and an area Apw2 into which p type impurities are introduced are formed across a border area Ad having a specified interval, so the impurity density of the junction part of a diode is less than when those areas are formed adjacently. Consequently, the reverse withstand voltage of the diode can be increased. Further, even when introduction conditions of the n type or p type impurities and heating conditions of a semiconductor substrate 1 in well formation are predetermined, the reverse withstand voltage of the diode can optionally be set by adjusting the interval of the border area Ad, so the diode can be formed by using the well forming stage in an ordinary CMOS process.
Abstract:
PROBLEM TO BE SOLVED: To stably carry out wireless communication. SOLUTION: A loop antenna 61 of a reader/writer transmits or receives a signal to/from a loop antenna 81 of an IC card by electromagnetic coupling. Stable wireless communications can be attained by connecting a chip inductor 62 with the loop antenna 61 in series so that in the range of larger coupling coefficient K34, the received voltage V4 which the loop antenna 81 receives is made higher than the voltage which is needed for the operation of an IC card. This invention is applicable to an information processor. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a signal processing device, capable of effectively preventing erroneous recognition from occurring in a host device by the occurrence of unwanted fluctuations in a signal, when turning on/off a power supply in a circuit for outputting a signal, such as interrupts to the host device. SOLUTION: When a first circuit 2 has not been started, the signal S1 is maintained at a prescribed value. For the start of the first circuit 2, determination is made, according to whether a plurality of pulses are outputted from the circuit 2, after the power has been turned on, thus preventing the propagation of an unnecessary changes in the signal S1 occurring in an unstable state, when the power of the first circuit 2 rises to a second circuit 3 (host device), and hence effectively preventing misoperations and decrease in processing capability in the host device. By preventing the unwanted processings in the host device, wasteful power consumption can be restrained. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a communication apparatus which is capable of preventing an excessive voltage of an antenna circuit in transmission without deteriorating communication performance, and a mobile terminal comprising the same. SOLUTION: If an abnormally high voltage is generated in an antenna circuit 113 while transmission is performed as a reader/writer, a signal output from a transmission circuit 112 to the antenna circuit 113 is stopped so that transmission power supplied to the antenna circuit 113 is reduced, thereby returning the voltage of the antenna circuit 113 into a normal range. Since operation in the case of the abnormal voltage is estimated not to excessively enlarge a current capacity of a clamp circuit 119, an increase in the area of circuit can be suppressed. Furthermore, it is not necessary to form a circuit by a special manufacturing process of high voltage resistance, so that a design time or costs can be suppressed. Moreover, the abnormal voltage can be suppressed without deteriorating the performance of the antenna circuit 113. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
A non-volatile memory device including a plurality of block, each including: a main bit line; a plurality of sub-bit lines to which memory transistors are connected and which are arranged in parallel with respect to the main bit line; and two cascade-connected selection gates which are provided between the main bit line and sub-bit lines and which selectively connect the sub-bit lines.
Abstract:
A non-volatile memory device including a plurality of block, each including: a main bit line; a plurality of sub-bit lines to which memory transistors are connected and which are arranged in parallel with respect to the main bit line; and two cascade-connected selection gates which are provided between the main bit line and sub-bit lines and which selectively connect the sub-bit lines.
Abstract:
PROBLEM TO BE SOLVED: To realize a nonvolatile semiconductor memory in which threshold voltage after erasion can be controlled highly accurately by predicting an erasion characteristic based on a write-in characteristic, and performing memory erasion conforming to erasion conditions set in accordance with the above. SOLUTION: An erasion characteristic predicting means predicts an erasion characteristic in accordance with correlation between a write-in characteristic previously obtained and an erasion characteristic based on a write-in characteristic of a memory cell, and stores obtained erasion characteristic information in a storage means. At the time of erasion operation, erasion conditions, for example, the number of times of applying erasing pulse until reaching the prescribed threshold voltage is set by an erasion means in accordance with stored erasion characteristic information, as erasion operation is performed conforming the above, threshold voltage of a memory cell after erasion can be controlled to near the previously set erasion target value, threshold voltage of a memory cell after erasion can be controlled highly accurately without performing erasion verifying.