The LM3557SD-2/NOPB, manufactured by Texas Instruments, is a high-efficiency, fixed-frequency, step-up DC-DC converter specifically designed to drive white LEDs with a constant current. This device is ideal for portable applications where efficient power conversion is a priority, such as smartphones, tablets, and other handheld devices.

Key Features

• Integrated Switch: The LM3557SD-2/NOPB includes an integrated 40V N-channel MOSFET switch, enabling it to easily drive a series string of LEDs.
• Constant Current Output: The output current can be programmed between 28.5mA to 1.2A, ensuring uniform brightness for the LEDs.
• High Efficiency: With a fixed-frequency operation and low feedback voltage, the device operates at a high efficiency, which is critical for battery-powered applications.
• Small Footprint: The device is offered in a compact 10-pin WSON package, making it suitable for space-constrained applications.
• Thermal Shutdown: It includes a thermal shutdown feature, enhancing the safety and longevity of the device by preventing overheating.

Applications

The LM3557SD-2/NOPB is versatile and can be used in a variety of applications, including:

• Backlighting for LCD displays
• Keypad illumination for mobile devices
• General LED lighting
• Portable flashlights
• Signal and symbol lighting

Additional Information

As a RoHS-compliant product, the LM3557SD-2/NOPB is designed with environmentally friendly materials. It also features a simple, external PWM dimming capability, allowing for flexible control over the brightness levels of the LEDs. With its robust design and comprehensive protection features, this converter is a reliable choice for driving high-brightness LEDs in a variety of portable applications.

Note: For detailed technical specifications, application circuits, and layout guidelines, refer to the LM3557SD-2/NOPB datasheet provided by Texas Instruments.