Miniature Motor Control for Portables

FREE Design Examples, Design Tools, and Daughter Card

Actel offers a demonstration platform that showcases IGLOO devices as controllers for miniature brushless DC and stepper motors. Using this platform, you can evaluate an IGLOO device as a flexible motor controller for your designs.

The platform consists of a motor control daughter card for Actel's IGLOO Icicle Kit. The motor control daughter card is comprised of a miniature brushless DC and stepper motor with some associated motor driver circuits. The block diagram shows the Icicle board connected to the miniature motor daughter card. All functions can be controlled using the GUI software on a PC or through hardware control using DIP and toggle switches on the daughter card. The data is communicated between the PC and Icicle board through a USB cable with a USB-to-UART chip that allows a simple UART controller on the IGLOO device to communicate with the PC.

Motor control design examples aid in the development of motor control applications and are available for free download from the Actel website, independent of the Motor Control Daughter Card.

• Brushless DC motor control example controls a sensored brushless DC motor with Hall Effect feedback. The Hall Effect sensors provide the position of the rotor to determine the next state. Three logic signals are decoded to determine the next winding sequence. The duty cycle of the 8-bit PWM signal varies the speed of the motor. The PWM frequencies can be made variable based on motor specifications.
• Stepper motor control example controls the commutation for a 4-wire stepper motor. The stepper motor requires a fixed sequence of phase voltages that must be supplied to the motor windings for proper commutation. Four vectored signals from an IGLOO device directly control the H-bridge in full-step and half-step mode. A PWM technique is used to implement micro-step mode by varying the duty cycle of the applied voltage in trapezoidal form with 8 or 16 steps.

To begin designing for portables with IGLOO FPGAs today, you can download and license the FREE Libero IDE software and motor control design examples. In order to try out the design on board, you can order the Icicle Demonstration Kit from Actel and the Motor Control Daughter Card from Avnet Memec.