Microchip公司的MTD6505是三相全波无传感器BLDC马达控制器,具有180度正弦驱动,高转矩输出和安静驱动,工作电压2V到5.5V,内置频率发生器(FG),锁住保护和自动恢复电路,过流限制,热关断保护和风细雨过压保护.主要用在笔记本电脑CPU冷却风扇和5V三相BLDC马达.本文介绍了MTD6505主要特性,方框图,典型应用电路以及三相BLDC无传感器风扇控制器演示板主要特性,电路图和材料清单.
The MTD6505 device is a 3-phase full-wave sensorless driver for brushless DC (BLDC) motors. It features 180° sinusoidal drive, high torque output and silent drive. With the adaptive features, parameters and wide range of power supplies (2V to 5.5V), the MTD6505 is intended to cover a broad range of motor characteristics, while requiring minimum external components. Speed control can be achieved through either power supply modulation (PSM) or pulse-width modulation (PWM).
The compact packaging and the minimal bill-of material make the MTD6505 device extremely cost efficient in fan applications. For example, the CPU cooling fans in notebook computers require designs that provide low acoustic noise, low mechanical vibration, and are highly efficient. The frequency generator (FG) output enables precision speed control in closed-loop applications.
The MTD6505 device includes Lockup Protection mode to turn off the output current when the motor is in a lock condition, with an automatic recovery feature to restart the fan when the lock condition is removed.Motor overcurrent limitation and thermal shutdown protection are included for safety enhanced operations.
The MTD6505 is available in a compact, thermally enhanced, 3mm x 3mm 10-lead UDFN package.

MTD6505主要特性:
• 180° Sinusoidal Drive, for high efficiency and low acoustic noise
• Position Sensorless BLDC Drivers (No Hall-effect sensor required)
• Integrated Power Transistors
• Supports 2V to 5.5V Power Supplies
• Programming Resistor (RPROG) setting to fit motor constant (Km) range from 3.25 mV/Hz to 52 mV/Hz
• Direction Control:
- Forward direction: connect DIR pin to GND or leave floating
- Reverse direction: connect DIR pin to VBIAS or 3V
• Speed Control through Power Supply Modulation (PSM) and/or Pulse-Width Modulation (PWM)
• Built-in Frequency Generator (FG Output Signal)
• Built-in Lockup Protection and Automatic Recovery Circuit
• Built-in Overcurrent Limitation
• Built-in Thermal Shutdown Protection
• Built-in Over Voltage Protection
• No External Tuning Required
• Available Package 10-Lead 3mm x 3mm UDFN

MTD6505应用:
• Notebook CPU Cooling Fans
• 5V 3-Phase BLDC Motors

图1. MTD6505方框图

图2. MTD6505典型应用电路图

MTD6505三相BLDC无传感器风扇控制器演示板
MTD6505 3-Phase BLDC Sensorless Fan Controller Demonstration Board 
The MTD6505 3-Phase BLDC Sensorless Fan Controller Demonstration Board allows the control and monitoring of the MTD6505 device using PC software connected to the board via a USB connection. The included board software provides several features including V_DD control and monitoring, pulse-width modulation (PWM) control, speed and current consumption monitoring. It also allows selecting the R_PROG resistor value for fan fitting.

风扇控制器演示板包括:
• 1x MTD6505 3-Phase BLDC Sensorless Fan Controller Demonstration Board (ADM00345)
• 3x Plug-In Modules with soldered on MTD6505 (3x3x0.5 mm UDFN-10L)
• 1x 3-Phase BLDC fan
• 1x Mini-USB cable

图3. MTD6505三相BLDC无传感器风扇控制器演示板外形图风扇控制器演示板

风扇控制器演示板主要特性:
• Abilities to control and monitor a 3-Phase BLDC fan or motor through the MTD6505 device
• Four selectable K_M ranges through GUI software
• Advanced measurements is available for broad range of 3-Phase BLDC fan validation

图4.风扇控制器演示板电路图