原标题：Linear LT3652HV采用太阳能的电池充电方案

　　Linear 公司的LT3652HV是完整的单片降压电池充电器,工作电压从4.95V到34V,具有恒压/恒流充电特性,最大充电电流可达2A.输入电压可采用太阳能峰值能量跟踪(MPPT),可并行使用以得到更大输出电流,固定频率1MHz,浮充电压精度达0.5%,充电电流精度5%,主要应用在太阳能,遥控监视,手提仪表,12V-24V汽车系统以及采用限流适配器的电池充电.本文介绍了LT3652HV主要特性, 方框图以及多种应用电路.

　　The LT.3652HV is a complete monolithic step-down battery charger that operates over a 4.95V to 34V input range. The LT3652HV provides a constant-current/constant-voltage charge characteristic, with maximum charge current externally programmable up to 2A. The charger employs a 3.3V float voltage feedback reference, so any desired battery fl oat voltage up to 18V can be programmed with a resistor divider.

　　The LT3652HV employs an input voltage regulation loop, which reduces charge current if the input voltage falls below a programmed level, set with a resistor divider. When the LT3652HV is powered by a solar panel, the input regulation loop is used to maintain the panel at peak output power.

　　The LT3652HV can be configured to terminate charging when charge current falls below 1/10 of the programmed maximum (C/10). Once charging is terminated, the LT3652HV enters a low-current (85μA) standby mode. An auto-recharge feature starts a new charging cycle if the battery voltage falls 2.5% below the programmed fl oat voltage. The LT3652HV also contains a programmable safety timer, used to terminate charging after a desired time is reached. This allows top-off charging at currents less than C/10.

　　LT3652HV主要特性:

　　Input Supply Voltage Regulation Loop for Peak Power Tracking in (MPPT) Solar Applications

　　Wide Input Voltage Range: 4.95V to 34V (40V Abs Max)

　　Programmable Charge Rate Up to 2A

　　User Selectable Termination: C/10 or On-Board Termination Timer

　　Resistor Programmable Float Voltage Up to 18V Accommodates 4-Cell Li-Ion/Polymer, 5-Cell LiFePO4, Lead-Acid Chemistries

　　Parallelable for Higher Output Current

　　1MHz Fixed Frequency

　　0.5% Float Voltage Reference Accuracy

　　5% Charge Current Accuracy

　　2.5% C/10 Detection Accuracy

　　Binary-Coded Open-Collector Status Pins

　　LT3652HV应用:

　　Solar Powered Applications

　　Remote Monitoring Stations

　　Portable Handheld Instruments

　　12V to 24V Automotive Systems

　　Battery Charging from Current Limited Adapter

　　图1. LT3652HV方框图

　　图2. LT3652HV应用电路图(1)

　　图3. LT3652HV应用电路图(2):2A太阳能电池板管理器

　　图4. LT3652HV应用电路图(3):2A单个LiFePO4电池充电器