原标题：Microchip QI无线充电LED手提灯参考设计

　　microchip公司的 QI无线充电LED手提灯是Qi 1.1标准(最大5W功率)兼容的接收器,和任何Qi 1.1兼容的无线充电发送器相连接.采用通用的8位微处理器(PIC16F18325)进行通信和充电,为通用无线充电解决方案提供了灵活低成本替代方案.该设计方案是能无线充电的手持和灵活照明解决方案.从无线接收器线圈的输入电压为4.5V到28V,低压电源为+5V(采用MCP1804 LDO).微控制器固件所实现的为Qi 1.1 5W无线充电器通信协议.设计师采用2000 mAh锂电池(4.2V充电1A).3个LED串(9V时的驱动电流最大为200mA).设计采用同步降压转换器拓扑以得到高效率,双向降压或升压转换器,由PFM信号驱动,提供充电和放电模式;降压模式给电池充电,而升压模式从电池给LED串供电.四级LED调光水平为25%,50%,75%和100%.中电网为您整理如下详细资料,本文介绍了参考设计简化框图和QI无线充电LED手提灯参考设计主要特性,电路图,材料清单和PCB设计图.

　　The Microchip Qi Wireless Charging LED Lantern is a Qi 1.1 standard (5W maximum power) compatible receiver. It provides a flexible, low-cost alternative to the common wireless charging solutions by using a general purpose 8-bit microcontroller for communication and charging.The Microchip Qi Wireless Charging LED Lantern can be used in conjunction with any Qi 1.1 - compatible wireless charging transmitters. It has the added functionality of a fully featured Lithium-Ion charging controller and the high efficiency of a switching power supply.

　　The Qi Wireless Charging LED Lantern Reference Design is a portable and flexible lighting solution which can be charged wirelessly. The design demonstrates features of a Qi 1.1 compatible wireless receiver which opens the possibility of encapsulating the end solution, making it dust and waterproof.A synchronous, bidirectional buck or boost converter is used in order to obtain high effi-ciency and to implement the battery charging algorithm and the LED driving functions. A full charging algorithm for Lithium-Ion batteries is implemented in the microcontroller’s firmware, providing safe charging.The lantern’s lighting intensity can be selected with the help of a button, having four dimming levels. A 14-pin PIC16F18325 microcontroller is used to implement all the functions on the board (Qi communication protocol, buck and boost regulation’s con-trol, battery charging algorithm, LED dimming).

　　The Qi Wireless Charging LED Lantern Reference Design kit includes:

　　• Qi Wireless Charging LED Lantern Reference Design LED Board

　　• Important Information Sheet

　　Qi Wireless Charging LED Lantern Key Features.The Microchip Qi Wireless Charging LED Lantern is developed to offer a flexible, low-cost alternative demo solution to the already existing wireless charging products.The key features of the Microchip Qi Wireless Charging LED Lantern that allow the users to quickly add accessible wireless charging functionality to other applications are:

　　• Receiver implementation using a general purpose 8-bit microcontroller

　　• Compatibility with the Qi 1.1 (5W) standard, allowing the receiver to be used with any Qi 1.1 compatible wireless charging transmitters

　　• Accurate power measurement to aid the Foreign Object Detection (FOD) function

　　The Qi Wireless Charging LED Lantern Reference Design is developed to demonstrate a Qi 1.1 receiver implementation coupled with a bidirectional switching power supply that enables battery charging and LED driving. The board demonstrates how to implement a Qi 1.1 wireless receiver, charge a Lithium-Ion battery from a receiver and boost the battery voltage to drive a string of LEDs, using a PIC16F18325 microcontroller and a number of analog components.

　　图1.QI无线充电LED手提灯参考设计简化框图

　　QI无线充电LED手提灯参考设计主要特性:

　　• Input voltage from wireless receiver coil: +4.5V to +28V

　　• Low voltage power: +5V (using a MCP1804 LDO)

　　• Qi 1.1 5W Wireless Charger communication protocol implemented in microcon-troller’s firmware

　　• Designed to use 2000 mAh Li-Ion battery (charging 1A at 4.2V)

　　• 3 LEDs string (200 mA max. driving current at 9V)

　　• Synchronous buck converter topology, leading to high efficiency

　　• Bidirectional buck or boost converter, driven by a PFM signal, providing charging and discharging modes, buck mode in order to charge the battery and boost mode to supply the LED string from the battery

　　• Full charging algorithm for Lithium-Ion batteries implemented in firmware

　　• Four dimming levels for LEDs: 25%, 50%, 75% and 100%

　　图2.QI无线充电LED手提灯参考设计外形图

　　图3. QI无线充电LED手提灯参考设计板电路图