Motor drive device, motor system and electronic device

A motor drive device, comprising:

• a current detector, configured to detect a current flowing through a motor coil;
• a control unit, configured to perform a slow decay mode for attenuating the current after a current-feeding mode ends in each cycle;
• and
• a determination unit, configured to determine whether the current at a second time point after a predetermined time has elapsed from a first time point when the current-feeding mode is switched to the slow decay mode and is below a limit value,
• wherein a length of the predetermined time is a value obtained by multiplying a time from the first time point to an end of the current cycle by a predetermined ratio between 0 and 1,
• wherein when the determination unit determines that the current is not below the limit value, the control unit is configured to, at the second time point, switch the slow decay mode to a fast decay mode that attenuates the current more rapidly than the slow decay mode,
• each of the cycles only includes one continuous current-feeding mode and one continuous current decay mode, and
• each of the current decay modes only includes the slow decay mode or both the slow decay mode and the fast decay mode.