Motor drive device, motor system and vehicle

A motor drive device configured to drive a motor using at least one half-bridge which includes an upper transistor and a lower transistor and in which the motor is connectable to a node where the upper transistor and the lower transistor are connected, the motor drive device comprising:

• at least one of a second main electrode pull-down switch configured to be able to pull down a second main electrode corresponding to the node in the upper transistor including a first main electrode configured to be able to apply a power supply voltage and a second main electrode pull-up switch configured to be able to pull up the second main electrode;
• a check performance unit configured to perform an abnormality check operation for at least one of the upper transistor, the lower transistor and the motor in a state where the second main electrode is pulled up or pulled down by bringing one of the second main electrode pull-down switch and the second main electrode pull-up switch into an on state;
• and
• a control circuit configured to control a combination of on/off states of the upper transistor, the lower transistor and a motor relay connected to the motor,
• wherein the check performance unit is configured to check, at startup, for at least one of a short circuit and an open circuit of the upper transistor, a short circuit and an open circuit of the lower transistor, a short-to-power and a ground fault of the motor and a short circuit and an open circuit of the motor relay.