Denso Corporation

Takaharu Hutamura

Hiroyuki Ban

Shoichi Okuda

Nobuyoshi Osamura

In a power supply circuit, a main transistor, which transmits power from an input terminal to an output terminal, is controlled so that a detected voltage from an input voltage is consistent with a reference voltage indicating a target voltage. An output current is detected and a limited value of the output current is set so that the limited value increases gradually when the output voltage rises up to the target voltage. The main transistor is controlled so that the output current keeps a value less than or equal to the limited value. This configuration is able to suppress an overshoot of the output voltage, thanks to a gradually raised control of the limited value. Additionally, to avoid the influence of a ringing component of the input voltage, a delay control circuit to give a delay to the start of rise of the output voltage can be provided.

Power supply circuit with control of rise characteristics of output voltage

A drive circuit for driving a switching element is provided which includes a high-side switching circuit connected between power supply lines, a low-side switching circuit connected in series with the high-side switching circuit through an output terminal leading to the switching element, and a voltage detector detecting a voltage appearing at the output terminal. When the voltage detected by the voltage detector is lower than a given off-decision voltage, that is, when the switching element is placed in the off-state, the low-side switching circuit is brought into the off-state, thereby reducing the current consumption thereof.

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Anjo, Japan

Takaharu Hutamura