ADI公司的ADP5065是一款內嵌互聯直流電壓充電輸出端與電池端的FET器件，通過FET可以實現電池隔離，當系統驅動電能來自于廢電池或沒有電池時，系統會立即切換到USB供電模式。ADP5065的輸入電壓范圍為4V至5.5V，最大輸入電壓高達20V。ADP5065充電器兼容USB2.0、USB3.0和USB電池充電規范1.1。本文通過總結ADP5065器件的特點，分別介紹器件、特性、應用方向及內部結構框圖，并給參考設計實例原理圖、制板圖及元器件清單。
The ADP5065 charger is fully compliant with the USB 2.0, USB 3.0, and USB Battery Charging Specification 1.1 and enables charging via the mini USB VBUS pin from a wall charger, car charger, or USB host port.
The ADP5065 operates from a 4 V to 5.5 V input voltage range but is tolerant of voltages of up to 20 V. This alleviates the concerns about the USB bus spiking during disconnect or connect scenarios.
The ADP5065 also features an internal FET between the dc-to-dc charger output and the battery. This permits battery isolation and, hence, system powering under a dead battery or no battery scenario, which allows for immediate system function on connection to a USB power supply.
Based on the type of USB source, which is detected by an external USB detection chip, the ADP5065 can be set to apply the correct current limit for optimal charging and USB compliance.
The ADP5065 comes in a very small and low profile 20-lead WLCSP (0.5 mm pitch spacing) package.
ADP5065主要特性：
3 MHz switch mode charger
1.25 A charge current from dedicated charger
Up to 680 mA charging current from 500 mA USB host
Operating input voltage from 4.0 V up to 5.5 V
Tolerant input voltage −0.5 V to +20 V (USB VBUS)
Dead battery isolation FET between battery and charger output
Battery thermistor input with automatic charger shutdown for when battery temperature exceeds limits
Compliant with the JEITA Li-Ion battery charging temperature specification
SYS_EN_OK flag to hold off system turn-on until battery is at minimum required level for guaranteed
system startup due to minimum battery voltage and/or minimum battery charge level requirements
EOC programming with C/20, C/10 and specific current level selection
ADP5065應用：
Digital still cameras
Digital video cameras
Single cell Li-Ion portable equipment
PDA, audio, GPS devices
Mobile phones
圖1. ADP5065方框圖
ADP5065設計原理圖：
圖2. ADP5065設計原理圖
ADP5065設計方案材料清單：
PCB元件布局圖：
