The BS3406A is a high-efficiency, fixed-frequency PWM (Pulse Width Modulation) step-up DC-DC converter manufactured by MPS Industries. It is designed to drive white LEDs or other constant-current loads. The device integrates a high-side power MOSFET and is capable of delivering up to 600mA of output current.

Applications

• LED Backlighting for LCD Displays
• Boost converters for portable devices
• LED flashlights
• Constant current sources
• General purpose DC-DC step-up conversion

Features

• Fixed Frequency PWM Control: Ensures stable operation and predictable EMI performance.
• Integrated High-Side MOSFET: Simplifies circuit design and reduces external component count.
• High Efficiency: Maximizes battery life in portable applications.
• Overvoltage Protection (OVP): Protects the output from excessive voltage.
• Short Circuit Protection (SCP): Protects the device from short circuit conditions.
• Thermal Shutdown Protection: Protects the device from overheating.

Benefits

• Longer Battery Life: High efficiency minimizes power consumption.
• Simplified Design: Integrated MOSFET reduces component count and simplifies layout.
• Robust Protection: Overvoltage, short circuit, and thermal shutdown protection enhance reliability.
• Stable Operation: Fixed frequency PWM control ensures predictable performance.
• Compact Solution: Small package size minimizes board space requirements.

Additional Details

The BS3406A requires a few external components to operate, including an inductor, a Schottky diode, and input/output capacitors. The switching frequency is typically around 1.2MHz. The input voltage range is typically from 2.5V to 6V, and the output voltage can be adjusted using an external resistor divider. The device is available in a small QFN package. Care should be taken when selecting the inductor and diode to ensure they are properly rated for the switching frequency and current requirements of the application. The datasheet provides detailed information on component selection and layout recommendations. Proper layout is crucial for minimizing EMI and ensuring stable operation. The BS3406A includes an enable pin that can be used to shut down the device and reduce power consumption in standby mode. Soft-start functionality helps to limit inrush current during startup.