Denso Corporation

Fuminari Suzuki

Shoji Miura

Akira Kuroyanagi

Takeshi Miyajima

Tomoatsu Makino

Mikimasa Suzuki

Yutaka Tomatsu

A load drive circuit, disposed to drive an inductive load, includes a reflux closed circuit connected to the load. A flywheel diode is placed in the reflux closed circuit. A MOS transistor, disposed to turn on/off current to drive the load, is connected in parallel to the flywheel diode. A capacitor is disposed to connect its both ends to a gate and a drain of the MOS transistor, while a resistor is disposed to connect its both ends to the gate and a source of the MOS transistor. During a recovery operation of the flywheel diode, with the help of the capacitor and resistor, a gate-to-source voltage of the MOS transistor is pulled up to a value over a threshold for a predetermined period of time. Pulling up the gate-to-source voltage results in a softened recovery characteristic of the flywheel diode, suppressing recovery surges.

Load drive circuit using flywheel diode

A semiconductor device has a semiconductor substrate, several cell blocks provided on the semiconductor substrate, several gate electrodes electrically independent of one another and respectively provided in the cell blocks, and several gate pads respectively connected with the gate electrodes. In this construction, the cell blocks can be determined whether they are defective or not by utilizing the gate pads easily. Therefore, the semiconductor device can be operated only with non-defective cell blocks.

Semiconductor device and method for manufacturing the same

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Fuminari Suzuki