HOW DOES IT WORK?

Brushless 25 Click is based on the MCT8316A, a high-speed sensorless trapezoidal control integrated FET BLDC driver from Texas Instruments. It is the ideal solution for applications requiring the high-speed operation of up to 3kHz of electrical speed, a very fast startup time of under 50ms for 12V to 24V BLDC motors, and fast deceleration of under 150ms. The driver's control is highly configurable through register settings stored in an onboard non-volatile EEPROM. This feature allows the device to operate as a stand-alone device once it has been configurated. In addition, the MCT8316A allows a high level of monitoring, where any variable in the algorithm can be observed as an analog output via two 12-bit DACs.

Brushless 25 Click uses a standard I2C 2-Wire interface that allows the host MCU to configure EEPROM settings and read detailed fault and motor state information. If a fault condition occurs, the MCT8316A will pull the FLT pin to a low logic state, with a FAULT LED as a visual presentation. The FG pin is used as a motor speed indicator and provides pulses proportional to motor speed. For connecting the three-phase BLDC motor, this Click board™ features the half-bridge output CBA screw terminal and a VM terminal for an external motor power supply. The RST pin can set the motor driver to sleep mode by turning all MOSFETs OFF.

There are three switches to control the connected motor manually. The speed can be controlled by a PWM or analog value, which can be selected via the SPEED CTRL switch. The PWM signal can be set over the corresponding pin of the mikroBUS™ socket, while the analog value can be set over the MCP4161, an 8-bit, single SPI digital potentiometer with non-volatile memory from Microchip. The motor driver expects up to 95KHz of PWM frequency or an analog voltage in 732μV resolution. In addition, this is also a way to wake up the motor driver from sleep mode.

The DIR switch changes the direction of the motor spinning with 0 and 1 positions. The low position (0) sets the phase driving sequence as ABC, while the high position (1) sets the ACB sequence. The I2C interface can overwrite this input. The Brake switch also has two states, with high entering the brake state. The MCT8316A will decrease the output speed to the threshold value and stay in the brake state as long as this switch is in a high position. This input also can be overwritten by the I2C interface.

In addition, the Brushless 25 Click comes with two headers above the mikroBUS™ socket for some optional feature addition. The VBK pin on the right-side unpopulated header is an output voltage pin from the internal buck regulator for some external loads. Other pins on this header are for monitoring algorithm variables and phase current feedback through DAC and SOX pins (the SOX pin can also be configured as one of the DAC pins). On the left side is an unpopulated header with E_WD and E_CLK signals acting as the external clock reference and watchdog input pins.

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

SPECIFICATIONS