The **LB1663** is a specialized integrated circuit (IC) developed by Sanyo (now part of ON Semiconductor). It is primarily designed as a **2-phase unipolar drive motor driver**, commonly used for driving brushless DC (BLDC) motors, such as those found in cooling fans. --- ### 1. Key Specifications and Features The LB1663 is known for its simplicity and reliability in small motor applications. | Feature | Description | | :--- | :--- | | **Function** | 2-Phase Unipolar Drive | | **Supply Voltage ($V_{CC}$)** | Typically 4V to 28V | | **Output Current** | Up to 1.5A (Peak) | | **Package Type** | Often found in SIP-10 (Single In-line Package) | | **Protections** | Built-in thermal shutdown and spark killer diodes | --- ### 2. Internal Block Components The IC integrates several electronic stages to minimize the need for external components: 1. **Hall Amplifier Stage:** Connects directly to a Hall Effect sensor to detect the rotor's magnetic position. 2. **Control Logic:** Processes the Hall signal to determine which phase (winding) of the motor should be energized. 3. **Output Drivers:** Power transistors (NPN) that switch the motor windings to ground. 4. **Protection Circuitry:** Includes "Spark Killers" (diodes) to absorb the inductive flyback voltage generated when the motor coils switch off. --- ### 3. Pin Configuration (Typical SIP-10) While you should always consult the specific datasheet for your manufacturer, the standard layout is as follows: | Pin No. | Name | Function | | :--- | :--- | :--- | | 1 | **$V_{CC}$** | Power Supply Input | | 2 | **OUT1** | Output 1 (Connects to Coil 1) | | 3 | **OUT2** | Output 2 (Connects to Coil 2) | | 4 | **GND** | Ground | | 5-6 | **Hall In** | Differential inputs from the Hall sensor | | 7 | **RD/FG** | Rotation Detection or Frequency Generator (Speed signal) | --- ### 4. Circuit Application Example In a standard cooling fan circuit, the LB1663 acts as the "brain" and "muscle": ```mermaid graph LR A[Hall Sensor] --> B(LB1663 IC) B --> C[Motor Coil 1] B --> D[Motor Coil 2] E[Power Supply] --> B ``` * **Unipolar Drive:** This means current flows in only one direction through the motor coils. The IC switches the ground side of the coils. * **Automatic Restart:** Most versions include a timeout feature. If the fan is physically blocked, the IC stops the drive to prevent overheating and periodically attempts to restart. ---