HOW DOES IT WORK?

Brushless 11 Click is based on the A4931, a 3-phase brushless DC motor pre-driver from Allegro Microsystems. It uses six external N-channel MOSFETs to drive a 3-phase BLDC motor. The internal charge pump generates a supply to drive the high-side MOSFETs while the voltage is internally monitored. In case of a fault condition, the device outputs are disabled. The pre-driver features several protection mechanisms, including fault shutdown, overvoltage protection, overtemperature protection, hall state reporting, and mock detect function.

The A4931 also features the HBIAS function, which provides a power supply voltage of 7.5V with a current limited to 30mA. This referent voltage powers the logic sections of the pre-driver and the external Hall elements. These elements can be connected over the 6-pin header, labeled as positive and negative A, B, and C channel inputs. To set the motor direction, this Click board™ uses a DIR switch. Set the position 1 for rotating forward and 0 position for rotating reverse.

Brushless 11 Click is controlled by the host MCU through GPIO logic states. The enable input terminal on pin EN is used for external PWM, with typically PWM frequencies in the 20 to 30kHz range. To use brakes and stop the motor, you should write a logic LOW on the BRK pin, which activates the Brake mode. This input overrides the enable input, and also the lock detect function. Both the EN and BRK pins are pulled up. There are FG1 and FG2 pins that let you accurately measure motor rotation.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

SPECIFICATIONS