Rohm Co., Ltd.

Hiroto Oshita

Yuhei Yamaguchi

Tetsuo Tateishi

Yosuke Fukumoto

Genki Tsuruyama

Yoju Imamura

Takatsugu Wachi

A switching power supply circuit includes: a switching circuit switching an input voltage; a first amplifier generating a first voltage; a first phase compensation circuit including a first capacitor and compensating for a phase of the first voltage; a second amplifier generating a second voltage; a second phase compensation circuit including a second capacitor and compensating for a phase of the second voltage; and a drive control circuit executing a switching operation according to the second voltage, wherein the switching power supply circuit operates in a first or second mode, the drive control circuit performs, in the first mode, the switching operation, and stops, in the second mode, the switching operation, and when returning from the second mode to the first mode, a specific voltage corresponding to an output voltage is supplied to the second capacitor and a predetermined voltage is supplied to the first capacitor.

Switching power supply circuit and switching power supply device

A pulse control devicecomprises: a switch output unitwhich generates a pulse output voltage Vo from a direct-current input voltage Vi and supplies the pulse output voltage Vo to a load (such as a relay coilof a mechanical relay); a low-pass filter unitwhich receives a feedback input of the pulse output voltage Vo and generates a feedback voltage Vfb; and an output feedback control unitwhich receives an input of the feedback voltage Vfb and controls the switch output unitso that an average value of the pulse output voltage Vo becomes constant. The low-pass filter unitmay be configured without a coil.

Pulse control device

A diving circuit drives an output transistor according to a control signal S. The gate of the first transistor is biased. The source of the first transistor is coupled to an internal line. In the on period of the output transistor, the voltage of the internal line is applied to a control electrode of the output transistor. A voltage correction circuit controls the internal line so as to gradually lower the voltage Vof the internal line with time.

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Kyoso, Japan

Hiroto Oshita