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.