bldc motor needs more complex control design and drive circuit. In place of the bldc motor single door driver and power field effect transistor, each phase of the bldc motor needs to take out 6 memory, each memory is composed of three half bridge pairs.
The designers of power tools are constantly taking on the task of cramming more electronics into the same or smaller space. The first is to switch off the wires by switching to battery powered equipment. Due to the need to save battery power, there are more complex control schemes, sensors and power drive devices, from brush DC motor to a more efficient bldc motor.
Wireless and BLDC blocks require very different feature sets. Control bldc motor calls high resolution pulse width modulation (PWM) timer, multi-channel analog-to-digital converter (ADC) with necessary conversion speed, general input/output (GPIOs) interrupt capability, and wired connection options. Wireless MCU needs to have RF front-end, high-frequency reference clock, digital phase-locked loop (PLL) and DSP modem and other functions.
Dividing wireless and BLDC functions into separate MCUs is a tested option, but it’s better to combine the two blocks into a single MCU. It creates a more compact solution while reducing power consumption and BOM costs. Of course, the selected microchip must contain the required peripheral blocks, processing power, and memory required to perform bldc motor and wireless functions.