应用与设计

具非常快闭锁负载断接功能的电路故障保护

详情介绍

概览

产品详情

Li-Ion Driver for Four White LEDs

LT1932 是一款固定频率升压型 DC/DC 转换器,其专为用作一个恒定电流源而设计。由于它直接调节输出电流,因此 LT1932 非常适合于驱动发光二极管 (LED),此类二极管的光强与流经它们的电流成比例,而不是其端子上的电压。 

由于输入电压范围为 1V 至 10V,所以该器件可采用多种输入电源供电运作。LT1932 即使在输入电压高于 LED 电压时也能准确地调节 LED 电流,从而极大地简化了电池供电型设计。单个外部电阻器负责把 LED 电流设定在5mA 和 40mA 之间,随后可以很容易地利用一个 DC 电压或一个脉宽调制 (PWM) 信号对其进行调节。当 LT1932 被置于停机模式时,将 LED 与输出断接,从而确保整个电路的静态电流低于 1µA。这款器件的 1.2MHz 开关频率允许使用纤巧的扁平片式电感器和电容器,以在对空间敏感的便携式应用中,将器件的占板面积和成本降至最小。

Efficiency

工具及仿真模型

LTspice

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

LTspice