Product specifications

R01AN0168ED0101 Rev. 01.01 11
Application Note
Chapter 3 About Stepper Motor Movement
3.1 The Physics of a Stepper Motor
The Stepper Motor consists of a permanent magnet, which rotates within the
magnetic fields of two coils.
Figure 3-1 Stepper Motor Coil Connection
By using two driver bridges (one for the horizontal coil, one for the vertical coil),
both coils can be driven currents in both directions. Depending on the device
hardware (port structures), either half-bridges or full-bridges are used.
Half-bridges are two push-pull drivers with high-impedance function, while full-
bridges are 4 discrete power transistors, which are forming a H-bridge, with the
motor coil in its middle.
Like this, when adding the forces of the magnetic fields of both coils, the motor
anchor can be rotated by changing the amplitude and direction of the fields.
Figure 3-2 Forces and Angle of the Stepper Motor