白光LED升压型转换器，SOT23封装

 

器件号	Replacement	Explanation

说明

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The MAX1848 drives white LEDs with a constant current to provide backlight in cell phones, PDAs, and other hand-held devices. The step-up converter topology allows series connection of the white LEDs so that the LED currents are identical for uniform brightness. This configuration eliminates the need for ballast resistors and expensive factory calibration. Other benefits include greater simplicity, lower cost, higher efficiency, and greater reliability.

This step-up PWM converter includes an internal, high-voltage, low R_DSON N-channel MOSFET switch for high efficiency and maximum battery life. A single analog voltage Dual Mode™ input provides a simple means of brightness adjustment and on/off control. Fast 1.2MHz current-mode PWM control allows for small input and output capacitors and a small inductor while minimizing ripple on the input supply/battery. Programmable soft-start eliminates inrush current during startup.

The MAX1848 is available in space-saving 8-pin thin QFN (3mm x 3mm) and 8-pin SOT23 packages.

MAX1848：典型应用电路 放大+

关键特性

• Constant Current Regulation for Uniform Illumination
• High 87% Efficiency
• Analog or Logic Control of LED Intensity
• 0.8W Output Power with Internal High-Voltage MOSFET Switch
• Small, Low-Profile External Components
• 2.6V to 5.5V Input Range
• 13V Maximum Output with Overvoltage Protection
• Optimized for Low Input Ripple
• Programmable Soft-Start
• 0.3µA Shutdown Current
• Small 8-pin Thin QFN (3mm x 3mm) and 8-Pin SOT23 Packages

应用

• 蜂窝电话/智能电话
• 电子书与亚笔记本电脑
• PDA、掌上电脑与无线手持装置
• 白色LED显示器背光