AllegroA4934三相风扇控制办理方案

Allegro 公司的A4934是三相马达驱动器,它接纳BEMF检测,从而在风扇应用是不需要霍尔传感器.PWM输入用来控制马达的转速,具有软开关以低落可听噪音,FG速度输出,低功耗待机模式和锁定检测.本京电港论坛文章先容了A4934主要特点和优势,功能方框架图,典范应用电路及相应的元件值.

The A4934 three-phase motor driver incorporates BEMF sensing to eliminate the requirement for Hall sensors in fan applications.

A pulse wave modulated (PWM) input is provided to control motor speed, allowing system cost savings by eliminating external variable power supply. PWM input can also be used
as an on/off switch to disable motor operation and place the IC into a low power standby mode.

The A4934 soft switching settings are designed for lower inductance or lower speed motors. For higher inductance or higher speed motors consider using the pin-compatible A4941.

The A4934 is provided in a 16-pin TSSOP package (suffix LP) with an exposed thermal pad. It is lead (Pb) free, with 100% matte tin leadframe plating.

A4934主要特点和优势:

• Sensorless (no Hall sensors required)

• Soft switching for reduced audible noise

• Minimal external components

• PWM speed input

• FG speed output

• Low power standby mode

• Lock detection

• Optional overcurrent protection

图1{京电港论坛}.A4934功能方框架图

图2{京电港论坛}.A4934典范应用电路原理图纸:通过VBB调解速度

典范应用的元件表:

详情请复制打开此衔接地址:
http://www.allegromicro.com/en/Products/Part_Numbers/4934/4934.pdf