The LB11822 is a single-chip bipolar IC designed by SANYO Semiconductor for use in 3-phase brushless DC motor applications. It provides electronic commutation, drive, and speed control functions, minimizing the need for external components. The IC is particularly suited for fan motors and other low-voltage, low-power BLDC motor applications.

Applications

• Cooling Fans (CPU Coolers, Case Fans)
• Small Brushless DC Motors
• Hard Disk Drive (HDD) Spindle Motors
• Optical Disc Drive (ODD) Spindle Motors
• General Purpose Motor Control

Features

• 3-Phase Full-Wave Drive: Provides efficient and smooth motor operation.
• Built-in Hall Amplifier: Amplifies the signals from external Hall effect sensors for rotor position detection.
• Speed Control Function: Allows for adjusting the motor speed using an external voltage or PWM signal.
• FG Output: Provides a frequency generator (FG) output signal for speed monitoring and feedback control.
• Lock Protection: Prevents motor damage in the event of rotor lock-up.
• Thermal Shutdown: Protects the IC from overheating.
• Low Voltage Operation: Designed for operation at low supply voltages.

Benefits

• Simplified Motor Control: Reduces the number of external components required for 3-phase BLDC motor control.
• Improved Efficiency: Full-wave drive and optimized circuitry provide high energy efficiency.
• Precise Speed Control: Allows for accurate and stable motor speed regulation.
• Enhanced Reliability: Built-in protection features prevent motor and IC damage.
• Compact Design: Enables smaller and more compact motor control systems.

Additional Details

The LB11822 typically operates from a supply voltage of 3V to 18V. It integrates Hall amplifiers to read the signals from external Hall effect sensors which detect the rotor position. The IC then uses this information to control the 3-phase output stages, driving the motor windings in the correct sequence. The speed of the motor can be controlled by applying a DC voltage to the speed control input or using a PWM signal. The FG output provides a signal whose frequency is proportional to the motor speed, allowing for closed-loop speed control. The IC also includes a lock protection function, which stops the motor if the rotor becomes locked, preventing damage to the motor and the drive circuitry. The thermal shutdown function protects the IC from damage due to excessive heat.