Kabushiki Kaisha Toshiba

Toshiba Electronic Devices & Storage Corporation

Tatsuhiko Maruyama

Toyoaki Uo

According to the present embodiment, a power supply circuit includes a first transistor, a feedback voltage generation circuit, a first voltage generation circuit, and a protection circuit. The first transistor is connected between an input terminal and an output terminal. The feedback voltage generation circuit divides the output voltage to generate a feedback voltage. The first voltage generation circuit supplies a voltage to a first control terminal of the first transistor via a first node based on the feedback voltage and a reference voltage. The protection circuit outputs a voltage that makes the first transistor non-conducting or places the first transistor in a state where the first transistor has a predetermined high resistance value to the first control terminal, when the input voltage increases above a first threshold voltage within a predetermined time.

Power supply circuit having protection circuit against electrostatic discharge stress and semiconductor device having the power supply circuit

A semiconductor device according to the present embodiment includes a plurality of switching elements and a plurality of variable capacitance elements. The switching elements are switching elements connected in series between a first control terminal and a second control terminal and plural types of capacitance control signals can be supplied to the first control terminal and the second control terminal. The variable capacitance elements have capacitance control terminals connected to corresponding one ends of the switching elements, respectively.

Semiconductor device, digitally controlled oscillator, and control method of semiconductor device

A voltage conversion apparatus includes an output unit connected to an input voltage to output an output voltage according to a control signal. A comparator compares a reference voltage to a feedback voltage corresponding to the output voltage and outputs a comparison signal. A delay circuit outputs a delayed signal obtained by delaying either a rising timing or a falling timing of the comparison signal. The delay circuit varies a delay time of the delayed signal on basis of a modulating signal. A control circuit is configured to output the control signal to the output unit. The control signal is based on the delayed signal. The control circuit controls the output unit such that a frequency of the output voltage is tuned to a predetermined value set according to the modulating signal.

Voltage conversion apparatus including output unit, comparator, delay circuit, and control circuit

According to an embodiment of the present invention, a power supply device includes a switching circuit, a detection circuit, a first comparator, a current source circuit, and a delay circuit. The switching circuit performs switching control of a power supply voltage. The detection circuit detects an output voltage from the switching circuit. The first comparator compares the voltage detected by the detection circuit with a first reference voltage which is set in advance. The current source circuit outputs a bias current which has correlation with the power supply voltage. The delay circuit receives the bias current from the current source circuit, and outputs, to the switching circuit, a delay time which corresponds to an increase time of the output voltage, by using the bias current in accordance with the result of comparison performed by the first comparator.

Growing community of inventors

Kawasaki Kanagawa, Japan

Tatsuhiko Maruyama