Overview
The LB1871 and LB1871M are three-phase brushless motor driver ICs that are optimal for LBP and LBF polygon mirror motor drive. The LB1871 and LB1871M are versions of the LB1870 and LB1870M in which the value of the divisor has been changed.

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.