Rohm Co., Ltd.

Tomohisa Shinozaki

Shun Fukushima

Tsutomu Ishino

Disclosed is a control circuit of a boost DC-DC converter including a high side transistor and a low side transistor, and a load switch connected between the high side transistor and an output line of the boost DC-DC converter. The control circuit includes a pulse modulator that generates a pulse signal with a pulse modulated to bring an output voltage of the output line close to a target level, a logic circuit that generates a high side control signal and a low side control signal based on the pulse signal, a load switch drive circuit that drives a first PMOS transistor provided as the load switch, and a current detection circuit that generates a current detection signal indicating a current flowing through the first PMOS transistor. The load switch drive circuit is switchable between a first mode and a second mode.

Control circuit of boost DC-DC converter, power supply circuit, and electronic device

Disclosed herein is a control circuit of a boost DC/DC converter having a high-side transistor and a low-side transistor. The circuit includes an input pin that receives an input voltage of the boost DC/DC converter, a pulse modulator that generates a pulse signal pulse-modulated in such a manner that output of the boost DC/DC converter comes close to a target state, a logic circuit that generates a control signal of the high-side transistor and a control signal of the low-side transistor on the basis of the pulse signal, and a switch driving circuit that drives a load switch that is a PMOS transistor connected to the high-side transistor and a load between them. When stopping the boost DC/DC converter, the switch driving circuit applies a voltage corresponding to the input voltage of the boost DC/DC converter to a gate of the PMOS transistor.

Control circuit and power supply circuit of DC/DC converter, and electronic equipment

A control circuit of a boost DC/DC converter including a high side transistor and a low side transistor, includes a pulse modulator including a first error amplifier that amplifies an error between a reference voltage and a feedback signal corresponding to an output voltage of the converter, the pulse modulator being configured to generate a pulse signal with a pulse modulated, a logic circuit that generates a high side control signal and a low side control signal, and a load switch drive circuit that drives a load switch that is a PMOS transistor connected between the high side transistor and a load. The load switch drive circuit can make a switch between a first mode for fully turning on the PMOS transistor and a second mode for supplying a drive voltage corresponding to the output signal of the first error amplifier to a gate of the PMOS transistor.

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Kyoto, Japan

Tomohisa Shinozaki