Rohm Co., Ltd.

Kiminobu Sato

Shinji Kawata

Kazuhiro Murakami

Ryosuke Sumii

A semiconductor device includes a clock terminal to and from which a clock is allowed to be input and output, and a data terminal to and from which data is allowed to be input and output. In the semiconductor device, the data synchronized with the clock that is input to the clock terminal or is output from the clock terminal is output from the data terminal, and when the clock is output from the clock terminal, the clock is output irrespective of whether or not data transfer of the data is being executed.

Clock and data signal transmission in a master/slave PMIC system

A semiconductor integrated circuit device includes a control unit configured to control a switching element or an output transistor of a power supply device, a monitor terminal for monitoring an output voltage of the power supply device, a test unit configured to output a test signal to the monitor terminal before activation of the power supply device, and a determination unit configured to determine whether or not the monitor terminal is open, on the basis of a voltage of the monitor terminal when the test unit outputs the test signal to the monitor terminal.

Semiconductor integrated circuit device

A voltage monitoring circuit for monitoring an output voltage of a power supply device. The power supply device includes a voltage conversion part that converts an input voltage to the output voltage according to a difference between a feedback voltage based on the output voltage and a first reference voltage. The voltage monitoring circuit includes: a threshold voltage generation circuit configured to generate a threshold voltage from the first reference voltage; and a comparator configured to compare the threshold voltage with the feedback voltage.

Voltage monitoring circuit with adjustable thresholds

A power supply circuitincludes an output circuit that generates an output voltage by performing a power supply operation based on an input voltage, an output terminal to which, after start-up of the power supply operation, the output voltage is applied, and a control circuit that causes a test current to flow between the output terminal and a ground. The control circuit detects, as a test voltage, a voltage at the output terminal in a test period in which the test current is caused to flow. When the test voltage at a predetermined judgment timing is lower than a judgment voltage, the control circuit judges that an output capacitor is connected and thus enables the power supply operation.

Power supply circuit

A soft start circuit accepts an input of a reference voltage set arbitrarily, and generates a soft start voltage that takes a predetermined sweep time to slowly rise from a predetermined lowest value to a highest value that is higher than the reference voltage and changes in accordance with the reference voltage.

Soft start circuit

A switching power supply device has a reference voltage generator for generating a reference voltage, a ripple injector for generating a ripple by use of a pulse voltage indicating the on/off state of a switching element and injecting the ripple into the reference voltage, an integrated voltage generator for generating an integrated voltage commensurate with the integrated value of the pulse voltage throughout its on/off-duty periods, a subtractor for lowering according to the integrated voltage the reference voltage before injection of the ripple or the supply voltage to a buffer that feeds the ripple injector with the pulse voltage after making its pulse height constant, a comparator for comparing a feedback voltage with the reference voltage after injection of the ripple, and a switching controller for generating an output voltage from an input voltage by non-linear control by turning on/off the switching element according to the output of the comparator.

Growing community of inventors

Kyoto, Japan

Kiminobu Sato