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.