Abstract: To provide a mobile device with an AM radio which can reduce noise mixed in with a wiring drawn from a bar antenna. A cell-phone 100 includes a bar antenna 22 including a magnetic core and an antenna coil wound around the magnetic core and an AM radio tuner section 20 for performing an AM detection process to a broadcast wave received by the bar antenna 22 and outputting a sound signal after detection. The AM radio tuner section 20 is a one-chip component formed on a semiconductor substrate except for a certain external component, and the one-chip component is placed in proximity to the bar antenna 22.

Abstract: A receiver of double conversion system wherein unwanted components included in received signals can be removed without fail and wherein the number of constituent parts has been reduced. The receiver comprises an antenna tuning circuit 10 including a tuning coil 11 and a variable-capacitance diode 13; a high frequency amplification circuit 20 for performing a high frequency amplification of a signal outputted by the antenna tuning circuit 10; two-stage mixing circuits 22, 28 for performing two frequency conversions of an output from the high frequency amplification circuit 20; and a detecting circuit 36 for detecting an output from the latter-stage mixing circuit 28.

Abstract: When a coil 1b is arranged at the forward end of an antenna element 1a which resonates with the frequency band of portable phones and an effective length of the combination the antenna element 1a and coil 1b is set equal to the length at which the frequency band of FM broadcast resonates, the coil acts as low impedance, matching to the frequency band of FM broadcast, and acts as high impedance for the frequency band of portable phones which is higher than the frequency band of FM broadcast. Consequently, the coil 1b can serve both as a matching coil for passing the frequency band of FM broadcast and a trap coil for blocking the passage of the frequency band of portable phones.

Abstract: In order to provide an image rejection circuit that can reject an image signal without being affected by manufacturing variations in circuit elements such as resistors, condensers, or the like, an image rejection circuit is provided which comprises a first mixer unit 2 for mixing a signal received by a receiver device with a first local oscillation signal generated by a local oscillator 1, a second mixer unit 3 for mixing the received signal with a second local oscillation signal obtained by shifting the local oscillation signal generated by the local oscillator 1 by 90°, a polyphase filter circuit 4 including condensers C1 and switched capacitors, and a composition/output unit 5 for composing and outputting the IF signals output from the polyphase filter circuit 4.

Abstract: The purpose of the present invention is to improve a detection accuracy of a pilot signal detection circuit. A pilot detection signal voltage is input to a differential amplifier circuit 16 and a reference voltage generated by a reference signal generation circuit 17 is input to a differential amplifier circuit 19. A pilot signal is compared with the reference voltage by the differential amplifier circuits 16 and 19. Output currents of the differential amplifier circuits 16 and 19 are converted into voltages by a current-to-voltage conversion circuit 21. And an input to the current-to-voltage conversion circuit 21 is fed back with a voltage proportionate with an offset voltage of the circuit and the offset voltage of the pilot signal detection circuit is cancelled.

Abstract: This invention includes a gain control section 13 capable of changing an APC loop gain according to a power output level set in a power amplifier to allow suppression of variation in power output level when the power output level is low and suppression of occurrence of ringing when the power output level is high by making the loop gain high when the power output level is low and making the loop gain low when the power output level is high.

Abstract: A mixer circuit is configured using a CMOS transistor (800), comprising a p-channel transistor (840A) and an n-channel transistor (840B) in which semiconductor substrates (810A, 810) with at least two crystal planes and a gate insulator (820A) formed on at least two of the crystal planes on the semiconductor substrate are comprised and the channel width of a channel formed in the semiconductor substrate along with the gate insulator is represented by summation of each of the channel widths of channels individually formed on said at least two crystal planes. Such a configuration allows reduction of 1/f noise, DC offset generated in output signals due to variation in electrical characteristics of a transistor element, and signal distortion based on the channel length modulation effect.

Abstract: A receiver in which the sneaking noise from a crystal oscillator is reduced. A high-frequency amplifier circuit 11, a mixing circuit 12, a local oscillator 13, intermediate-frequency filters 14 and 16, an intermediate-frequency amplifier circuit 15, a limit circuit 17, an FM detection circuit 18, and a stereo demodulation circuit 19, an oscillator 20, and a PLL circuit 21 all constituting an FM receiver are provided as a one-chip component 10. A crystal oscillator 31 as an external component is connected to the oscillator 20. The natural-oscillation frequency of the crystal oscillator 31 is so set that the fundamental component and its harmonics are out of the reception band.

Abstract: An integrated circuit includes CMOS circuit blocks and analog control lines arranged outside a layout of the CMOS circuit blocks so that the analog wiring and circuit blocks do not overlap each other. The distance of signal lines within a circuit block and the analog control lines can become as long as necessary, and the signal line within the circuit block and the analog control lines are not coupled via parasitic capacitance, and mutual interference is suppressed. In another aspect, a method of arranging a semiconductor integrated circuit includes providing a plurality of functional circuit blocks and connecting analog control wiring to the functional circuit blocks. The analog control wiring is arranged outside a layout of the functional circuit blocks on the semiconductor integrated circuit so that the analog control wiring does not overlap any one of the functional circuit blocks so as to reduce or eliminate interference between signal lines within a circuit block and the analog control lines.

Abstract: An electronic apparatus comprising a speaker section 2 for outputting sound from a sound radiating section 2a, box section 3 comprising a space capable of containing the speaker section 2, box guide section 4 for coupling an electronic apparatus body 1 with the box section 3 and for guiding movement of the box section 3 so that sound is outputted toward the space in the box section 3 from the sound radiating section 2a when the box section 3 is moved by the box guide section 4 from a state containing the speaker section 2 to a state exposing the speaker section 2 at the time of outputting sound from the speaker section 2. Users can listen to adequate quality sound even with the minimized speaker section 2 because the adequate quality sound produced from the sound outputted from the sound radiating section 2a in the speaker section 2 and the sound resonated in the space of the box section 3 can be outputted.

Abstract: A modulation output device including; a DSP 12 for subjecting MP3 music data and the like read out from an MP3 player 50 to stereo modulation, when necessary; D/A converter 14 for converting the digital data outputted from the DSP 12 to an analog signal and outputting the converted analog signal to either an earphone terminal 54 or transmission part 15; and transmission part 15 for transmitting the analog signal outputted from the D/A converter 14 to the outside through a transmission antenna 55 enables the processing concerning reproduction of music data and processing for modulation of the reproduced music data to transmit without wires to be performed by a single DSP 12 and a single D/A converter 14.

Abstract: A semiconductor part 1 in which a metal terminal 2 is formed on its back surface and side surface is mounted so that only the back surface portion of the metal terminal 2 is in contact with a cream solder 3. When the side surface portion of the metal terminal 2 is irradiated with laser beams, the back surface portion of the metal terminal 2 is heated by thermal conduction from the side surface portion to the back surface portion of the metal terminal 2 and the cream solder 3 in contact with the back surface portion of the metal terminal 2 is melted, whereby soldering is performed.

Abstract: A comparator (12) for compensating the pulse width of the drive control signal of a power amplifier (54) by using a sense signal of an offset voltage generated between the nodes (H, I) of the power amplifier (54) is provided to enlarge the time width from the OFF operation of a pair of switching elements (Q1, Q4) to the ON operation of a pair of switching elements (Q2, Q3), thereby preventing the inconvenience that the switching elements (Q1, Q2) simultaneously turn on and suppressing a through-current. The pulse width for turning on the switching elements (Q1, Q4) is so corrected as to be wider or narrower than the pulse width for turning on the switching elements (Q2, Q3), thereby adjusting the intensity of an impressing voltage and canceling the offset voltage.

Abstract: An object is to provide a noise removing circuit that can be integrally formed on a semiconductor substrate and can improve the accuracy of noise component removal. The noise removing circuit comprises a highpass filter detecting a noise component included in an input signal, a pulse generating circuit generating a pulse signal corresponding to the detected noise component, an analog delaying circuit 252 delaying the input signal, and an outputting circuit removing the noise component included in the delayed signal according to the output timing of the pulse signal. The analog delaying circuit 252 delays the output timing of the input signal by making switches 51 to 56 electrically continuous in a sequential order, by holding the voltage of the input signal at each time point in a plurality of capacitors 81 to 86, and by extracting the held voltage before being updated by making switches 61 to 66 electrically continuous.

Abstract: A receiver and a composite component for preventing noise produced by sneaking of a local oscillation signal. An FM receiver comprises a high-frequency amplifier circuit 11, a mixing circuit 12, a local oscillator 13, intermediate-frequency filters 14 and 16, an intermediate-frequency amplifier circuit 15, a limit circuit 17, an FM detection circuit 18, and a stereo demodulation circuit 19. The mixing circuit 12 and the local oscillator 13 constitute a one-chip composite component 30 integrally formed on a semiconductor substrate. The frequency of the local oscillation signal is set so that the difference of frequency between the local oscillation signal and a modulated wave signal may be smaller than the occupied bandwidth of the modulated wave signal.

Abstract: A receiver capable of reducing a low-frequency noise generated when a component is integrally formed on a semiconductor substrate by using CMOS process or MOS process. A high-frequency amplifier circuit 11, a mixing circuit 12, a local oscillator 13, intermediate-frequency filters 14 and 16, an intermediate-frequency amplifier circuit 15, a limit circuit 17, an FM detection circuit 18, and a stereo demodulation circuit 19 constituting an FM receiver are formed as a one-chip component 10. This one-chip component 10 is formed on a semiconductor substrate by using the CMOS process or the MOS process. The amplification elements contained in the mixing circuit 12, the intermediate-frequency filters 14 and 16, the intermediate-frequency amplifier circuit 15, and the local oscillator 13 are formed by using the p-channel type FET.

Abstract: A receiver such that the period required for tracking adjustment, temperature compensation is not needed, and tracking errors due to fluctuation of the power supply voltage are prevented from increasing, and a tracking adjusting method for the receiver. A DAC 4 generates a voltage according to the value of data (Do) inputted from an MPU 81 by using a control voltage outputted from a low-pass filter 35 in a local oscillator 3 as a reference voltage used during digital-analog conversion. A multiplier circuit 5 analog-multiplies the output voltage of the DAC 4 by a predetermined multiplier. The output voltage of the multiplier circuit 5 is applied as a tuning voltage to a high-frequency tuning circuit 20.

Abstract: A received signal level is detected in each of a wide band, middle band, and narrow band and each detected signal is converted to a digital signal. A DSP 18 determines the enabled/disabled state of an LNA 3 and an attenuator 4 as well as a gain adjustment amount based on the signal level of each band. For example, the gain adjustment is not performed when the signal level of the narrow band including a desired frequency is not larger than a prescribed value even the signal level of the wide band or middle band is larger than a prescribed value. When the signal level of the narrow band is larger than the prescribed value exceeding a gain adjustable limit level in the attenuator 4, the gain of the LNA 3 is adjusted, while maintaining the gain adjustable amount in the attenuator 4 around the limit level, to reduce the gain as a whole.

Abstract: In order for circuit blocks 1 to 3 composed by the CMOS process, and analog lines 5?1, 5?2, and 5?3 connected thereto not to overlap on the layout, the analog lines 5?1 and 5?2 are wired so that such lines roundabout the layout of the AM/FM common circuit block 3. Through this, the distance of the signal line within the AM/FM common circuit block 3 and the analog lines 5?1 and 5?2 can become as long as possible, the signal line within the AM/FM common circuit block 3 and the analog lines 5?1 and 5?2 would not be coupled via parasitic capacity, and mutual interference occurring between the signal line and the analog lines 5?1 and 5?2 can be suppressed. In another aspect, a semiconductor integrated circuit with a CMOS structure includes an analog circuit and a feedback loop, wherein an analog signal line for the feedback loop is wired outside a layout of the analog circuit.

Abstract: A couple of frequency doubler circuits 21 and 22 which multiplys a frequency of a reference oscillation signal outputted from a reference oscillator 12 is provided, thereby a frequency of a reference oscillation signal, as the greatest common divisor between a frequency (300 KHz) determined by multiplying the frequency (fx=75 KHz) of a crystal oscillator 11 by four and a frequency (54 KHz) determined by multiplying an assigned frequency per one channel in AM radio broadcasting by a prescribed divide ratio, can be higher than a conventional frequency. This way realizes the decrease of a divide ratio in a programmable counter 17, resulting in the reduction of the circuit scale, shortening of the lock-up time, and improvement of the S/N ratio.