With the rapid adoption of smart home technologies, bathroom exhaust fans have evolved from basic heating and lighting devices into integrated systems combining ventilation, lighting, sterilization, and intelligent temperature control. As the core ventilation component, the fan quickly removes moisture and stale air, maintaining a dry and comfortable indoor environment.
Early products mainly used asynchronous motors. To meet modern requirements for low noise, high efficiency, strong airflow, and improved ventilation, BLDC motor solutions are replacing traditional designs and have become the mainstream choice in next-generation products.
For BLDC exhaust fan applications, Geehy introduces the G32M3101 sensorless FOC control solution. It delivers low noise, stable speed, smooth forward/reverse switching, and high-precision stepless speed control. The solution also offers strong cost efficiency, reducing overall system cost by approximately 10–20% compared to similar solutions.
G32M3101 Bathroom Exhaust Fan Application
The system is based on the highly integrated G32M3101 motor control SoC, featuring an Arm® Cortex®-M0+ core operating up to 64MHz, with 64KB Flash and 8KB SRAM. It adopts a sensorless FOC vector control algorithm. A PID controller performs closed-loop speed regulation, generating the required current vector, while an observer estimates rotor position and speed with high accuracy.
G32M3101 Bathroom Exhaust Fan Application
Partial Algorithm Overview of Motor Driver Layer
Solution Advantages
• Single-Chip Integration: Integrates MCU, LDO, and 3P+3N pre-driver with built-in op-amps and comparators, simplifying circuitry, reducing BOM cost, and minimizing PCB size.
• Sensorless FOC Control: Reduces electromagnetic noise and lowers overall acoustic noise for improved user experience.
• Optimized Startup Algorithm: Ensures 100% startup success with stable operation across 0–1800rpm.
• Flexible Dynamic Response: Enables fast acceleration/deceleration, smooth forward/reverse switching, and seamless speed transitions.
• Multiple Speed Control Interfaces: Supports USART, PWM, and VSP control with fault indication and one-key shutdown.
• Wide Voltage Compatibility: Supports 12V–30V DC input (compatible with 12V/24V systems), covering 20W–60W applications.
• Flexible Parameter Configuration: Supports user-defined tuning and rapid application deployment.
• Comprehensive Protection: Includes over/under-voltage, overcurrent (hardware/software), blocked airflow, and stall protection.
• Low-Cost Design: Supports cost-effective MOSFET selection to reduce total system cost.
• Proven Reliability: Verified in high-volume deployments with stable and reliable performance.
G32M3101 Bathroom Exhaust Fan Application Block Diagram
G32M3101 Motor Control SoC Overview
• High-Performance Processing: Cortex-M0+ @ 64 MHz with hardware DIV/MULT for efficient FOC execution.
• Highly Integrated Architecture: MCU + gate driver + LDO in a single chip.
• High-Speed ADC: 12-bit ADC up to 2 MSPS with DMA support.
• Rich Analog Peripherals: Integrated 2 op-amps and 2 comparators, up to 8 PWM channels with dead-time insertion and brake input, optimized for motor control.
• Flexible Packaging: Available in QFN32, LQFP32, and SSOP28/24 packages.
The G32M3101 bathroom exhaust fan application combines a highly integrated SoC with advanced motor control algorithms. It supports flexible adaptation to different motors and applications through parameter configuration and algorithm tuning. Geehy also provides a general-purpose evaluation board to accelerate performance evaluation, development, debugging, and algorithm migration.
G32M3101 Motor Evaluation Board
G32M3101 Bathroom Exhaust Fan Application Schematic
Customer Solution Board
