The A3906 integrated circuit from Allegro MicroSystems (www.allegro.com) consists of a single stepper motor control or dual low voltage DC motor control for operation with voltages from 2.5 to 9 V. The circuit has an internal current limit PWM and output peak current warning. Furthermore, its outputs are low (rds9on) for less dissipation, and it has a “brake” mode for DC motors. In the figure we have the application circuit for two common DC motors. The values of the resistors depend on the application and more information about their calculation can be obtained in the datasheet available on the Allegro website. For controlling a stepper motor, the configuration is shown in the figure. In sleep mode, the device enters a low power condition. The maximum output current for both circuits is 1 A and the component can be obtained in a 20-contact QFN housing with an exposed pad to help with heat dissipation.
