原标题：Linear LTC4079高效高压线性充电解决方案

　　Linear公司的LTC4079是低静态电流的高效高压线性充电器,输入电压2.7V-60V,可调电池电压从1.2V到60V,可调充电电流从10mA到250A,适用于大多数电池如锂电池,铅酸或镍锰电池等.主要用在嵌入汽车电子和工业,能量收集充电器,薄膜电池产品和备用电池充电器.本文介绍了LTC4079主要特性,框图,多种电池的典型应用电路以及演示板DC2133主要特性,电路图和材料清单.

　　The LTCR4079 is a low quiescent current, high voltage linear charger for most battery chemistry types including Li-Ion/Polymer, Lead-Acid or NiMH battery stacks up to 60V. The maximum charge current is adjustable from 10mA to 250mA with an external resistor. The battery charge voltage is set using an external resistor divider.

　　With an integrated power device, current sensing and reverse current protection, a complete charging solution using the LTC4079 requires very few external components.

　　Thermal regulation ensures maximum charge current up to the specified limit without the risk of overheating. Charging can be terminated by either C/10 or adjustable timer.

　　Input voltage regulation reduces charge current when the input voltage falls to an adjustable level or the battery voltage, making it well suited for energy harvesting applications. Other features include temperature qualified charging, bad battery detection, automatic recharge with sampled feedback in standby for negligible battery drain, and an open-drain CHRG status output. The device is offered in a compact, thermally enhanced 10-lead (3mm× 3mm) DFN package.

　　LTC4079主要特性:

　　Wide Input Voltage Range: 2.7V to 60V

　　Adjustable Battery Voltage: 1.2V to 60V

　　Adjustable Charge Current: 10mA to 250mA

　　Low Quiescent Current While Charging: IIN = 4μA

　　Ultralow Battery Drain When Shutdown or Charged: IBAT < 0.01μA

　　Auto Recharge

　　Input Voltage Regulation for High Impedance Sources

　　Thermal Regulation Maximizes Output Current without Overheating

　　Constant Voltage Feedback with ±0.5% Accuracy

　　NTC Thermistor Input for Temperature Qualified Charging

　　Adjustable Safety Timer

　　Charging Status Indication

　　Thermally Enhanced 10-Lead (3mm × 3mm) DFN Package

　　LTC4079应用:

　　Embedded Automotive and Industrial

　　Backup Battery Charging from Another Battery

　　Energy Harvesting Charger

　　Thin Film Battery Products

　　图1. LTC4079框图

　　图2. LTC4079采用24V AC整流的铅酸电池涓流充电电路图

　　图3. LTC4079具有差分电压稳压的锂电池充电电路图

　　图4. LTC4079具有定时端的锂电池充电电路图

　　图5. LTC4079具有C/19端的超级电容充电器电路图

　　图6. LTC4079具有定时端的NiMH涓流充电器电路图

　　演示板DC2133

　　Demonstration circuit 2133A features a simple battery charger circuit using the LTC®4079 high-voltage monolithic linear charger. The DC2133 has an input voltage range from 2.7V to 60V and is capable of supplying up to 250mA charge current. The charge voltage is jumperselectable to 4.2V or 8.4V. Charge current is adjustable via the PROG pin and initially programmed for 99mA. In shutdown or when unpowered, LTC4079 consumes only 10nA from the battery.

　　DC2133A is initially configured to enable charging from application of VIN above the LTC4079 UVLO threshold.

　　L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

　　演示板DC2133主要特性:

　　The NTC input is connected to an on-board resistance to enable charging with only a 2-wire battery connection; however an external thermistor may be used with the NTC test point.Termination is accomplished by timer method. Charging status is reflected by the CHRG LED.

　　演示板DC2133材料清单: