【翻译来自美国的DIY】USB单一简单的LiPoly充电器_haoDIY

Lithium Polymer Batteries are a very common source of power today. 锂聚合物电池是一个很常见的权力来源今天。Many electronics gadgets have one inside, and they have some reasonable features. 许多电子产品都有一个内部,和他们有一些合理的特性。I've bought great batteries, with different sizes and capacities for my electronics projects. 我已经买了伟大的电池,用不同的大小和容量为我的电子产品项目。So long I'm using this batteries, coming the problem: charge them.这么长时间我使用这种电池,未来存在的问题:他们收费。

So, we start to find the correct circuit for my DIY charger. 所以,我们开始找到正确的电路为我的DIY充电器。After some Google research I found the Maxim MAX1811 IC. It's a single-cell Lithium battery charger that can be powered directly from a USB or from an external supply up to 6.5V. 经过一些谷歌研究我发现这句格言MAX1811 IC。这是一个单细胞锂电池充电器,可以直接从一个USB驱动或者从外部供应多达6.5 v。It's use a SO-8 Package, easy to solder and can be sampled at Maxim. 这是使用所以8包,容易焊料和可品尝到格言。Other chip features are:其他芯片的特点是:

You can select between 4.1V and 4.2V battery regulation point;您可以选择在4.1 v和4.2 v电池监管点;

• You can select between 100mA and 500mA current drain from USB;你可以选择100年之间•马和500毫安电流损耗从USB;

• There's a open drain pin (pin_8) for signaling end of charge condition (2.5V < VBATT < BATT Regulation Voltage);•有一个开放的泄销(销8)信号的电荷条件(结束2.5 v < VBATT <棉絮调节电压);

• A internal thermal loop limits the MAX1811 die temperature to +135°C by reducing the charging current as necessary.一个内部热循环•限制了MAX1811模温度+ 135°C通过减少充电电流是必要的。

According to datasheet, MAX1811 is specifically made for USB devices. 根据数据表,MAX1811是专门为USB设备。The minimum voltage to a common USB-powered device may be as low as 4.35V when cable and connector drops are considered. 一个常见的最低电压usb��电的装置可能会低至4.35 v当电缆和连接器滴被认为是。The MAX1811 is optimized for operation at these low input voltage levels. MAX1811操作的优化在这些低输入电压水平。But USB hubs may also provide as much as 5.5V!. 但USB集线器也可以提供多达5.5 v !。At high input voltages (5.5V) and low cell voltages (2.7V), the MAX1811's thermal loop may limit the charge current until the cell voltage rises.在高输入电压(5.5 v)和低电池电压(2.7 v),MAX1811的热循环可能限制电流,直到电池电压上升。

My design uses 500mA was charging current (pin 2 - SELI - pulled up), but MAX1811 only taken this current if the device is a USB powered source. 我的设计使用500 ma是充电电流(销2 - SELI -停),但只有采取MAX1811当前如果设备是一个USB供电的源。The other parts are two very common tantalum capacitors and a LED for charging indication. 其他部分是两个非常常见的钽电容和一个领导了充电指示。LED is ON on charging state, and OFF when it's end.LED是在充电状态,当它结束了。

Above you see the schematics and PCB of my version 1:以上你看到我的PCB电路图和版本1: