Overview
The LB1870 and LB1870M are three-phase brushless motor driver ICs that are optimal for LBP and LBF polygon mirror motor drive.
   
Functions and Features
• Single-chip implementation of all circuits required for
    LBP polygon mirror motor drive (speed control and
    driver circuits)
• Low motor drive noise level due to the current linear
    drive scheme implemented by these ICs. Also, small
    capacitors suffice for motor output oscillation
    suppression, with certain motors not requiring these
    capacitors at all.
• Extremely high rotational precision provided by PLL
    speed control.
• Built-in phase lock detector output
• Four motor speed modes set by switching the clock
    divider provided under internal clock/crystal oscillator
    operation. This supports 240, 300, 400 and 480 dpi.
• Use of an external clock allows arbitrary motor speeds.
• Built-in FG and integrating amplifiers
• Full set of built-in protection circuits, including current
    limiter, undervoltage protection, and thermal protection
    circuits.