A brushless angle grinder uses brushless motor technology and a solid silicon-steel laminated rotor to eliminate carbon brush wear. Compared with conventional tools, it delivers 20% more power while consuming 20% less energy, providing high efficiency, low noise, and a long service life. Brushless angle grinders are widely used for metal cutting, stone grinding, weld polishing, and industrial rust removal.
To meet this demand, Geehy has developed a G32F031-based controller application for low-voltage Li-ion brushless angle grinders:
• Core technology: Sensorless square-wave (trapezoidal) control for stable, efficient operation
• High performance: 1,600W output power and speeds of up to 30,000rpm
• Compact design: Small controller footprint for installation inside the handle
• Safety protection: Multiple built-in protection functions for safe operation
Together, these features help customers transition efficiently from conventional to brushless angle grinders and quickly capture new market opportunities.
Geehy G32F031 Li-Ion Low-Voltage Brushless Angle Grinder Controller Application
Geehy's Li-ion low-voltage brushless angle grinder controller is powered by the G32F031, Geehy’s new-generation motor control MCU. Its built-in DIV/MULT accelerator improves computing performance, while fast load protection and multi-step speed control support operating conditions such as polishing, fine grinding, and rough cutting. The application also uses the GHD3450, a 200V three-phase N-channel motor gate driver with 2.0A/2.7A source/sink current. Its strong drive capability enables high-current output and stable operation in high-power tools.
Application Block Diagram
Application Features
Efficient Computing and Control | • Built-in sensorless comparator-based startup algorithm enables smooth speed control. • Brushless control improves efficiency and service life while providing spark-free, stable operation. • Supports sensorless single-resistor square-wave control and initial position detection (IPD) to increase startup torque. • Supports pulse-width adjustment for compatibility with motors of different specifications. |
Comprehensive Safety Protection | • Soft start reduces startup torque shock and automatically adjusts output as the load changes, helping prevent motor damage caused by overload. • An optional gyroscope enables anti-collision, anti-kickback, and anti-drop protection, stopping the motor within milliseconds. • Protection functions include overvoltage, undervoltage, overcurrent, phase loss, stall, and overtemperature protection. • Strict power-up sequencing prevents unintended restarts and motor runaway at startup, helping protect users. |
High Integration and Cost-Effectiveness | • Multiple on-chip op-amps and comparators simplify peripheral circuitry and reduce signal interference, lowering key component costs by approximately 20% compared with mainstream applications. • The compact controller supports smaller angle grinder designs, making tools lighter, easier to carry, and more comfortable to use for extended periods. |
Flexible and Adaptable Hardware Design | • The hardware supports configurations with 6 or 12 parallel-connected NMOS transistors to meet different power requirements. |
Application Specifications
• 20V motor system supporting up to 70A output current and a maximum speed of 30,000rpm
• Soft-start function accelerates the motor from standstill to maximum speed in just 400–600 ms
• Six-step speed control
• Six LED indicators for displaying different operating states
• Built-in braking brings the motor to a complete stop within 2.5 seconds
• Integrated high- and low-temperature protection helps prevent hazards in extreme operating environments
Core Chips in the Li-Ion Low-Voltage Brushless Angle Grinder Controller Application
G32F031 New-Generation Motor Control MCU
The G32F031 features a 64MHz Arm® Cortex®-M0+ core, 64KB of Flash, 8KB of SRAM, and a built-in DIV/MULT accelerator. It also integrates a 12-bit ADC, op-amps, comparators, and other peripherals. These computing and control resources support high-speed operation while significantly shortening the development cycle.
GHD3450 200V Motor Gate Driver
The GHD3450 supports a supply voltage of 5.5–20V, a floating offset voltage of +200V, and 2.0A/2.7A source/sink current. Its integrated bootstrap diode, VCC/VBS undervoltage protection, and shoot-through prevention help ensure stable motor operation.
The application also supports the upcoming G32M3115, a highly integrated motor control SoC combining an MCU and gate driver. It features an Arm® Cortex®-M0+ core running at up to 64MHz, an integrated 6N 200V gate driver, a built-in DIV/MULT accelerator, and peripherals including op-amps and comparators. Its highly integrated architecture simplifies peripheral circuit design while reducing system size and cost.
Geehy motor control chips are manufactured using advanced domestic industrial-grade processes, providing strong noise immunity and excellent cost-performance for brushless angle grinders. Supported by Geehy's in-house motor control algorithms and local technical services, these stable and safe chip applications help power tool and garden tool manufacturers accelerate development and mass production.
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