The LB11850VA is a single-phase bipolar fan motor driver with speed control function that works with a speed feedback signal. A highly efficient, quiet and low power consumption motor driver circuit, with a high speed accuracy and large variable speed can be implemented by adding a small number of external components. This pre-driver is optimal for driving large scale fan motors (with large air volume and large current) such as those used in servers and consumer products.

• Pre-driver for single-phase full-wave drive
• On-chip speed control circuit
• External PWM input or analog voltage input enabling variable speed control
• On-chip soft start circuit
• Reactive current cut circuit incorporated
• Constraint protection and automatic reset functions incorporated
• FG (speed detection), RD (lock detection) output
• Constant-voltage output pin for hall bias