Overview

The LB1872 is a 3-phase brushless motor driver IC developed for driving the polygon mirror motor used in laser printers and similar products.

Functions and Features

• Integrates the circuits (speed control and driver circuits) required for laser printer polygon mirror motor drive in a single chip.

• Uses a current linear drive technique for minimal motor noise. Only a small capacitors are required for output oscillation prevention.

• PLL speed control adopted for high-precision rotation with excellent jitter characteristics.

• Phase lock detection output with a chattering prevention function

• Four rotation rates can be set up using a single crystal oscillator to support 240, 300, 400, and 600 dpi operation.

• Arbitrary rotation rates can be acquired when an external clock is used. • Deceleration function implemented by short-circuit braking (free running when stopped)

• Built-in FG and error amplifiers

• Full complement of protection circuits, including thermal protection, low voltage protection, and current limiter circuits, provided on chip.