原创基于一种数字可调级步进式稳压电源的设计

 2009-9-19 19:14  1120 3 3 分类: 电源/新能源


作者：时间：2009-05-10 来源:

Linear公司的LTC3824是4-60V输入的降压DC/DC转换器,集成了高压栅极驱动器,设计用来驱动外接P沟MOSFET. LTC3824的开关频率可编程至高达600kHz,并容易同步. LTC3824可配置成突发模式工作,以增加低电流时的效率,扩充电池使用时间. LTC3824可用在工业和汽车电源,通信电源以及分布电源系统.本文介绍了LTC3824的主要特性,方框图以及2V 2A和5V 2A降压转换器应用电路, 演示电路DC960电路图和所用材料清单. The LTC3824 is a step-down DC/DC controller designed to drive an external P-channel MOSFET. With a wide input range of 4V to 60V and a high voltage gate driver, the LTC3824 is suitable for many industrial and automotive high power applications. Constant frequency current mode operation provides excellent performance. The LTC3824 can be configured for Burst Mode operation. Burst Mode operation enhances low current efficiency (only 40μA quiescent current) and extends battery run time. The switching frequency can be programmed up to 600kHz and is easily synchronizable. Other features include current limit, soft-start, micropower shutdown, and Burst Mode disable. The LTC3824 is available in a 10-lead MSE power package. LTC3824主要特性: Wide Input Range: 4V to 60V Current Mode Constant Frequency PWM Very Low Dropout Operation: 100% Duty Cycle Programmable Switching Frequency: 200kHz to 600kHz Selectable High Efficient Burst Mode Operation: 40μA Quiescent Current Easy Synchronization 8V, 2A Gate Drive (VCC > 10V) for Industrial High Voltage P-channel MOSFET Programmable Soft-Start Programmable Current Limit Available in a Small 10-Pin Thermally Enhanced MSE Package LTC3824应用: Industrial and Automotive Power Supplies Telecom Power Supplies Distributed Power Systems 图1.LTC3824方框图图2. LTC3824 12V 2A降压转换器应用电路图3. LTC3824 5V 2A降压转换器应用电路 LTC3824演示电路DC960 Demonstration Circuit 960 is a high voltage, current-mode DC/DC step-down converter featuring the LTC3824 in a small 10-pin M SO P package. The board operates from a Vin range of5.5V–60V and outputs 5Vout@2A. The Converter uses a P-Ch M O SFET for the main switch resulting in a low parts count design. Operating frequency is set to 300kH z with the option to accept a synchronized external clock. A soft-start feature controls the output voltage slew rate at start-up, reducing current surges and voltage overshoots. Burst M ode operation that improves the effi-DC960 is easy to set up to evaluate the performance of the LTC3824. 图3. LTC3824演示电路DC960电路图 LTC3824演示电路DC960材料清单(BOM):