Abstract: A start-up routine for a brushless sensor-less DC motor inductively measures motor position angle rather than motor start phase and inductively calculates an acceleration trajectory based on motor position rather than motor parameters. Motor position angle is determined by measuring the rise time of each phase, computing sinusoidal components for each phase, then calculating the angular position based on the sinusoidal components. The acceleration trajectory is determined by computing time delays for each phase. To do this, angular acceleration of the motor is calculated by determining the change in angular position of the motor between two predetermined time intervals. The motor may then be spun up with a start-up routine that is not dependent on motor parameters, resulting in a more efficient and consistent performance.