AnalogicTech 公司的AAT2862是背景光LED驅(qū)動(dòng)和多個(gè)LDO照明管理單元,集成了基于電荷泵的照明管理電路和4個(gè)LDO線性穩(wěn)壓器.電荷泵為所有的LED輸出提供電源,并可配置多個(gè)LED,每個(gè)LED的輸出可編程至30mA,兩個(gè)LED輸出,每個(gè)可編程至60mA.而每個(gè)LDO可提供高達(dá)200mA的負(fù)載電流. AAT2862輸入電壓從2.7V到5.5V,可用在有照相功能的移動(dòng)設(shè)備,數(shù)碼相機(jī)和多媒體手機(jī).本文介紹了AAT2862的主要特性,功能方框圖,典型應(yīng)用電路以及評(píng)估板電路圖, 評(píng)估板MCU電路圖和元件列表.

　　AAT2862: Backlight LED Driver and Multiple LDO Lighting Management Unit The AAT2862 is a highly integrated charge pump-based lighting management unit with four linear regulators optimized for single-cELl lithium-ion/polymer systems.

　　The charge pump provides power for all LED outputs and multiple LED configurations are available. The LED outputs can be programmed up to 30mA each and two LED outputs can be programmed up to 60mA each. An I2C serial digital interface is used to enable, disable, and set the current to one of 32 levels. Current matching is better than 3% for uniform display brightness, and high current matching is better than 5% for uniform power dissipation.

　　The AAT2862 also offers four high-performance lownoise MicroPower low dropout (LDO) linear regulators. The regulators are enabled and their output voltages are set through the I2C serial interface. Each LDO can supply up to 200mA load current and ground-pin current is only 80μA making the AAT2862 ideal for battery-operated applications.

　　The AAT2862 is available in a Pb-free, space saving TQFN34-24 package and operates over the -40℃ to +85℃ ambient temperature range.

　　AAT2862主要特性:

　　Input Voltage Range: 2.7V to 5.5V

　　Tri-Mode Charge Pump

　　Drives up to Eight LEDs

　　32 Programmable Backlight Current with Auto-fade

　　Settings Ranging From 500μA to 30mA

　　Drives up to Two Auxiliary LEDs

　　1MHz Switching Frequency

　　Automatic Soft Start

　　I2C Selectable Drivers

　　Four Linear Regulators

　　200mA Output Current

　　200mV Dropout

　　I2C Programmable Output Voltage from 1.2V to 3.3V

　　Output Auto-Discharge for Fast Shutdown

　　Built-In Thermal Protection

　　Automatic Soft Start

　　-40℃ to +85℃ Temperature Range

　　TQFN34-24 Package

　　AAT2862應(yīng)用:

　　Camera Enabled Mobile Devices

　　Digital Still Cameras

　　Multimedia Mobile Phones

　　圖1.AAT2862方框圖

圖2.AAT2862典型應(yīng)用電路

圖3.AAT2862評(píng)估板電路圖

圖4.AAT2862評(píng)估板微控制器電路圖

表1.AAT2862評(píng)估板元件列表