Monolithic Digital IC Two-Phase Brushless Fan Motor Driver

Overview
The LB1868 is a 2-phase unipolar brushless motor driver. With only a few peripheral parts, lockup protection and automatic recovery can be implemented. The IC can be configured for 12V or 24V operation and a wide range of variations, from LOW speed to H-High speed and from 60 cm to 120 cm square using the same PCB. This makes it easy to design highly reliable fan motor installations.

Functions and Features
● Output protection Zener diode with variable withstand
   voltage
   Z1, Z2 pins open: VOLM = 57V (24V specification)
   Z1, Z2 pins shorted: VOLM = 32V (12V specification)
   External Zener diode connected across Z1 - VCC pins:
   support for fans with large drive current
● External resistor allows configuration for 12V or 24V.
● Direct Hall element connection possible (built-in Hall
   amplifier with hysteresis supports core without auxiliary
   electrode)
● Built-in output transistor with 1.0A output current
   (strengthened negative-current support for core without
   auxiliary electrode)
● Built-in rotation detection function: Low during rotation
   and High during stop
● Built-in lockup protection with automatic recovery
● Built-in thermal shutdown