Motor Driver and Motor Driving System

The present invention provides a motor driver and a motor driving system capable of suppressing power consumption when a motor is in a brake state. The motor driver of the present invention includes: a half-bridge power output section, including a high-side transistor and a low-side transistor; a high-side driving circuit, driving the high-side transistor; and a control portion. When switching to a brake mode, the low-side transistor is turned on and the control portion turns off the high-side driving circuit.