LEDbulb

這種小外形封裝的新型驅動器提供CABC模式和自動調光功能；進一步拓寬了該公司的白光LED背光產品線

致力於為工業和通信行業的客戶提供電源創新解決方案的AnalogicTech™（Nasdaq：AATI）日前推出AAT2868和AAT2869 LED背光驅動器。AAT2868和AAT2869是1x/1.5x雙模、基於電荷泵的高效白光LED背光驅動電路，可同時驅動四個恆流LED通道，並提供CABC（content adaptive brightness control）或DBC（dynamic backlight control），將能耗進一步降低了50%。為形成完整的照明解決方案，兩電路都帶有兩個低壓差（LDO）線性穩壓器。

“手持裝置中採用白光LED技術所面臨的兩大關鍵問題就是能耗和不同亮度級別實現平滑轉換，”AnalogicTech的顯示與照明產品線總監Phil Dewsbury表示，“消費者要求電池壽命長，以及更好的用戶體驗，我們新推出的產品的特徵在這些方面具備優勢。CABC功能能將能耗降低高達50%，而自動LED漸暗功能克提高用戶滿意度，同時還通過轉移LED電流漸小的通信和計時的負擔，簡化了編程。”

在CABC和調光功能方面，AAT2868為用戶提供脈寬調製（PWM）調光輸入進行外部亮度和漸暗控制，同時通過AS2CwireTM界面完全控制32檔LED電流的按比例變化。 AAT2869擁有不是手動PWM輸入，而是基於AS2C的自動調光和漸暗功能，降低了對系統資源的要求。 AAT2869具備自動調亮和調暗的功能,背光的開啟和關閉具有視覺舒適感。這兩種背光驅動電路都通過允許系統根據顯示圖像持續調節背光電流大小，從而更大地減少了能耗。

AAT2868 Key Features and Benefits:
•    2.7V to 5.5V Supply Voltage Range
•    Dual Mode 1x/1.5x Charge Pump for LED Driver
o    Drives Up to 4 LEDs with up to 31mA each
•    Linear LED Output Control Options
o    Max Current Set by AS2C wire with 32 Step Control
o    PWM Interface Dimming from 100% to 1% Duty Cycle with Frequency up to 100kHz
•    Charge Pump 0.9MHz Constant Switching Frequency
•    Automatic Soft-Start Limits Inrush Current
•    Dual 150mA LDOs
o    Enable and Output Voltage Set by AS2Cwire: 16 Combinations of 5 Output Voltages: 1.2V, 1.5V, 1.8V, 2.8V, & 3.0V
o    Integrated Discharge Resistor when Disabled
•    < 1.0microA in Shutdown
•    Short-Circuit Protection
•    -40°C to 85°C Temperature Range
•    TQFN3.0x2.2-18 Package

AAT2868 Typical Application

AAT2869 Key Features and Benefits:
•    2.7V to 5.5V Supply Voltage Range
•    Dual Mode 1x/1.5x Charge Pump for LED Driver
o    Drives Up to 4 LEDs with up to 31mA each
•    Linear LED Output Control Options
o    Max Current Set by AS2C wire with 32 Step Control
o    Programmable Fade-In and Fade Out
•    Charge Pump 0.9MHz Constant Switching Frequency
•    Automatic Soft-Start Limits Inrush Current
•    Dual 150mA LDOs
o    Enable and Output Voltage Set by AS2Cwire: 16 Combinations of 5 Output Voltages: 1.2V, 1.5V, 1.8V, 2.8V and 3.0V
o    Integrated Discharge Resistor when Disabled
•    < 1.0microA in Shutdown
•    Short-Circuit Protection
•    -40°C to 85°C Temperature Range
•    RoHS Compliant, Halogen-Free TQFN3.0x2.2-18 Package

AAT2869 Typical Application