TI BQ24040 1A单芯锂离子电池充电参考设计方案
TI公司的BQ24040是一款应用于面积受限的便携式锂离子和锂聚合物电池线性充电芯片，该芯片的供电部分可以来自于USB供电或AC电源适配器供电，可以使用廉价的未经校准的电源适配器进行供电，因具有高的输入电压供电范围及输入过压保护。电池充电分为三个阶段，条件充电阶段、恒流充电阶段、恒压充电阶段。在所有充电阶段，内部有监测控制回路，当芯片内部温度超过阀值时，通过减少充电电流实现对整体电路的保护。本文首先介绍芯片的简介、特性、内部框图及应用方向，并给出相应设计方案的设计原理图、元器件列表及PCB元件布局图。
The BQ24040 series of devices are highly integrated Li-Ion and Li-Pol linear chargers devices targeted at spacelimited portable applications. The devices operate from either a USB port or AC adapter. The high input voltage range with input overvoltage protection supports low-cost unregulated adapters.
The BQ24040 has a single power output that charges the battery. A system load can be placed in parallel with the battery as long as the average system load does not keep the battery from charging fully during the 10 hour safety timer.
The battery is charged in three phases: conditioning, constant current and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if an internal temperature threshold is exceeded.
BQ24040主要特性：
• CHARGING
– 1% Charge Voltage Accuracy
– 10% Charge Current Accuracy ..
