Monolithic Digital IC Two-Phase Brushless Fan Motor Driver

Overview
The LB1868M 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 between Z1 and 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
● ST pin for motor stop/drive (for standby mode of copiers
   etc.)
• FG output pin for rotation detection
• BC pin for kickback noise reduction (with 2 external
   capacitors)
• Built-in thermal shutdown