Overview
The LB11967V is a single-phase bipolar variable speed fan motor pre-driver that works with an external PWM signal. A highly efficient, quiet and low power consumption motor drivercircuit, with a large variable speed, can be implemented by adding a small number of external components.
This device is optimal for driving large scale fan motors (withlarge air volume and large current) such as those used in servers and consumer products.

Functions
•Pre-driver for single-phase full-wave drive
⇒ PNP-EMOS is used as an external power Transistor, enabling high-efficiency low-consumption drive by means of
the low-saturation output and single-phase full-wave drive. (PMOS-NMOS also applicable)
•External PWM input enabling variable speed control
⇒ Separately-excited upper direct PWM (f = 25kHz) control method, enabling highly silent speed control
•Compatible with 12V, 24V, and 48V power supplies
•Current limiter circuit incorporated
⇒ Chopper type current limit at start
•Reactive current cut circuit incorporated
⇒ Reactive current before phase change is cut to enable silent and low-consumption drive.
•Minimum speed setting pin
⇒ Minimum speed can be set with external resistor. The start assistance circuit enables start at extremely low speed.
•Constant-voltage output pin for Hall bias
•Lock protection and automatic reset functions incorporated
•(Rotation speed detection), RD (Lock detection) output