Sanyo Electric Co., Ltd.

Sanyo Semiconductor Co., Ltd.

Semiconductor Components Industries, LLC

Ryuji Yamamoto

Kazunori Nohara

Tomoshi Yoshida

Nobuyuki Ohtaka

Yuichi Inakawa

A power supply circuit comprises a power transistor, a differential amplifier, an I/V converter circuit, and an inverting amplifier, wherein the differential amplifier comprises a first current path in which a first resistor element, a first current mirror transistor, and a first control transistor are connected in series, and a second current path in which a second resistor element, a second current mirror transistor, and a second control transistor are connected in series, and the power supply circuit comprises a phase compensating capacitor element connected in parallel with the inverting amplifier, and a ripple removal rate improving capacitor element which is connected between ground and a connection point between the first resistor element and the first current mirror transistor, or between the ground and a connection point between the second resistor element and the second current mirror transistor.

Power supply circuit using amplifiers and current voltage converter for improving ripple removal rate and differential balance

When an output of an overall output terminal () of a power supply circuit () is switched from a series regulator section () to a switching regulator section (), a fifth switch () is switched OFF, to temporarily open a feedback loop of the switching regulator section (), a sixth switch () is maintained at an ON state, to output the output of the series regulator section () to the overall output terminal (), and an artificial feedback loop is formed between an output terminal of an error amplifier () and a second terminal of the error amplifier (), to output a voltage corresponding to the output of the series regulator section () to the output terminal of the error amplifier () and charge a phase compensating capacitor () of the switching regulator section ().

Power supply circuit

A semiconductor circuit () comprises a first terminal section () to be connected to a connection point of two external resistors; a second terminal section () to be connected to an external circuit; a voltage circuit section having a first terminal connected to the second terminal section (); a reference voltage circuit section () which outputs a predetermined voltage; an operational amplifier () having a first input terminal connected to the reference voltage circuit section (), a second input terminal connected to the first terminal section (), and an output terminal connected to a second terminal of the voltage circuit section; an abnormality detecting circuit which detects an abnormal voltage of the first terminal section (); a normal signal generating unit () which generates a normal signal; and a switching circuit which, when the abnormality detecting circuit detects the abnormal voltage, does not output a voltage based on the first terminal section () to the second terminal section () and instead outputs a normal voltage based on the normal signal to the second terminal section ().

Semiconductor circuit

A voltage regulatorincludes: a level shifting circuit unitshifting a first voltage, which is a voltage level of a first power source, to a target value of a second voltage to output the shifted first voltage; a voltage-to-current converting circuit unitvarying a magnitude of an output current to output the current while changing a direction of a current using a variable power sourcevarying a voltage to larger and smaller values than a center voltage of an arbitrarily variable voltage range; and an adder-subtracter circuit unithaving a first terminal on one side, the first terminal being connected to an output terminal of the level shifting circuit unit, and a second terminal on the other side, the terminal being connected to a resistance element disposed between the second terminal and an output terminal, the resistance element allowing an output current of the voltage-to-current converting circuit unit to flow therethrough as a bias current, wherein a second voltage Vis output from an output terminal

Voltage regulator

A power circuit outputs and applies an AC voltage and a DC voltage to respective terminals of a capacitor, so as to obtain an AC output voltage shifted in accordance with the DC voltage component. The power circuit comprises a first voltage adjuster for outputting an AC voltage and a first DC voltage, and a second voltage adjuster for outputting a second DC voltage. For a predetermined duration after turning on power, the power circuit supplies the first DC voltage from the first voltage adjuster and the second DC voltage from the second voltage adjuster, for application to respective terminals of the capacitor. After the predetermined duration has passed, the power circuit changes the voltage output from the first voltage adjuster to the AC voltage, and supplies the AC voltage and the second DC voltage for application to the respective terminals of the capacitor. With this arrangement, a required potential can be quickly achieved at the time of turning on power.

Power circuit applying AC voltage and DC voltage to respective terminals of a capacitor, for outputting AC voltage shifted in accordance with the DC voltage

A power circuit outputs and applies an AC voltage and a DC voltage to respective terminals of a capacitor, so as to obtain an AC output voltage shifted in accordance with the DC voltage component. The power circuit includes a first voltage adjuster for outputting an AC voltage, a second voltage adjuster for outputting a DC voltage, a first output terminal which outputs the AC voltage from the first voltage adjuster, and a second output terminal which outputs the DC voltage from the second voltage adjuster. The first output terminal is connected to one end of the capacitor, while the second output terminal is connected to the other end of the capacitor. The power circuit controls impedance between the first output terminal and the first voltage adjuster.

A band-pass filter device includes a band-pass filter having a characteristic for sufficiently passing signals belonging to a passing frequency band to be passed, a first trap circuit having a Q factor sufficiently higher than that of the BPF and attenuating signals belonging to a frequency band ranging frequencies higher than the passing frequency band, a second trap circuit for attenuating signals belonging to a frequency band ranging frequencies lower than the passing frequency band, a third trap circuit having a Q factor lower than that of the first trap circuit and attenuating an unnecessary component generated in the first trap circuit from the signal, a fourth trap circuit having a Q factor lower than that of the second trap circuit and attenuating an unnecessary component generated in the second trap circuit from the signal. When a first signal belonging to a passing frequency band and a second signal belonging to a frequency band ranging frequencies lower or higher than the passing frequency band are simultaneously supplied to a BPF device having this structure, the BPF device can selectively pass the first signal, and completely attenuate the unnecessary second signal. A structure comprising two BPF having different central passing frequencies, first and third trap circuits having relatively low Q factors, a second trap circuit having a high Q factor and eliminating an unnecessary component which cannot be removed by the first trap circuit can also realize such a good BPF device as described above.

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Yao, Japan

Ryuji Yamamoto