5.1.1 Angle Generation

A Hall event is a change of state of the Hall signal. In one cycle of the Hall signal, six Hall events can be detected. Each event indicates an angle movement of one sixth of the total cycle. This means that eachHall event indicates a change of 60° (electrical).

For ripple free operation, the raw angle is smoothened by interpolation to obtain a finer angle. This angle is used in the field oriented control (FOC) transformation. The following figure shows the Hall angle signals and the angle generated from these signals (assuming the Hall signals are active high).

Figure 5-2. Hall Signals and Angle Generation

The following figure shows the computed angle generation for the reverse direction of the active high Hall signals.

Figure 5-3. Hall Signals and Angle Generation for Reverse Direction