Power tools are a general term for tools powered by DC or AC motors. As the most important electromechanical energy conversion device, the motor can effectively improve the energy utilization efficiency and achieve the policy goal of energy saving and emission reduction by reducing the energy consumption of the motor. With the policy requirements of energy saving and consumption reduction and high-efficiency applications, BLDC motors continue to penetrate deeply in the field of power tools. Thanks to the high efficiency of BLDC, the current mainstream power tools in the market basically use BLDC, which can effectively prolong the battery life of power tools and output the torque of the brushless motor stably.

Due to the characteristics of BLDC non-inductive high efficiency, large torque and low cost. The brushless DC motor is a self-commutation type (self-direction conversion), so it is more complicated to control, and it is necessary to understand the rotor position and mechanism of the motor for commutation and steering. The current control method of the sensorless brushless DC motor mainly collects the zero-crossing signal of the motor’s back electromotive force through an analog-to-digital converter (ADC) or a comparator. Although the method and algorithm of the analog-to-digital converter to collect the back EMF is more complicated, because the analog-to-digital converter is integrated in the GD32 MCU, for a three-phase motor, three comparators can be saved, thereby saving volume and cost. The analog-to-digital converter needs to sample at a specific time point, and then compare it with the zero point through software to obtain the commutation moment of the brushless DC motor to predict the next commutation moment of the brushless DC motor.

Shenzhen Yingtai Technology Co., Ltd. launched a brushless DC drill solution based on GD32F310 MCU and GD30DR8306 three-phase gate driver, which can be widely used in industrial automation, instrumentation, medical, consumer electronics, automotive and other fields that require high-precision motor control.

▲ Block diagram of brushless DC drill system

GD32F310 series MCU

Arm Cortex-M4 @72MHz, support DSP instruction operation

Flash:64KB/32KB/16KB

SRAM:8KB/6KB/4KB

High-speed and high-precision 12-bit [email protected], 10 channels

Advanced timer x1, supports three-phase PWM complementary output and dead-time management

Universal timer x5

Flash with hardware encryption protection

Various serial communication methods: I2Cx2, SPIx2, USARTx2

Rich package types: TSSOP20/QFN28/ LQFP32/QFN32/LQFP48

Supply voltage: 2.6V~3.6V

Industrial-grade operating temperature range: -40℃~+85℃

GD30DR8306 series three-phase gate driver

Three-phase brushless motor drive

4.5V-30V supply voltage

Programmable drive current, up to 1A source and 1.2A sink

200kHz PWM input control

2 PWM modes (6x and 3x)

Built-in 5V/2A DC-DC step-down controller

Integrated 5V LDO

Due to the particularity of electric drill products, hardware needs to be monitored during power-on self-check and work to ensure safe and stable work:

Voltage: The specified working range works reliably. Low and high pressure protection

Current: The three-level current protection mechanism is adopted to ensure that it can work normally in various environments

Temperature: high-power devices are monitored and protected when the temperature exceeds the set temperature

Device protection: For device damage, the system detects and protects it to avoid damage to other components and potential safety hazards

technical parameter

plan display

Reviewing Editor: Tang Zihong

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