STL6700

The STL6700 series is a BLDC fan controller with driver. It has advanced closed-loop control within ±2.5% variation of rotation speed. The built-in advanced timing control improves the motor efficiency and vibration. The device supports direct PWM input to eliminate the circuit for PWM to DC conversion, thus reducing the external component counts. A friendly programming interface can adjust the settings for fan speed curve. The STL6700 series features a soft-start function with programmable incremental duty cycle from 10% to 44% and maximum 700ms to further smooth-out the power-up spike on the coil current, thus reducing the start-up noise and relaxing the power budget. Other important functions such as internal current limiting, thermal shutdown, lock protection, and etc. are also supported for fan control application. The STL6700 supports a scheme of lock detection and automatically cease the output current. Once the external resistance is relieved, the devices automatically recover to the previous speed. Various open-drain output types such as RD, Stop RD, Reversed RD, and FG, are implemented as the tachometer for system to monitor the speed of a DC fan with 4 or 8 magnetic poles.