A motor drive device has a spindle motor driver adapted to drive a spindle motor. the spindle motor driver includes lower side NMOSFETs, one for each phase, which connect and disconnect terminals, one for each phase, of the spindle motor to and from a ground terminal; a controller adapted to generate a switch control signal and a brake control signal; lower side pre-drivers, one for each phase, connected between an application terminal of an internal power supply voltage and the ground terminal and adapted to generate lower side gate signals, one for each phase, in accordance with the switch control signal to output the lower side gate signals to the lower side NMOSFETs, one for each phase; and a brake unit adapted to pull up to the internal power supply voltage all the lower side gate signals, one for each phase, in accordance with the brake control signal.