原标题：Intersil ISL97694A单个锂电池六路LED驱动方案

　　Intersil公司的ISL97692/3/4A是单个锂电池驱动的4四/六路LED驱动器, 静态电流仅为1mA,输入电压可低至2.4V.ISL97692是四路,提供8位PWM调光,可调频率高达30kHz, ISL97693是六路,Direct PWM调光控制,ISL97694A是六路,提供8/10/12位PWM调光,可调频率分别是30kHz,7.5kHz或1.875kHz.主要用于平板电脑,笔记本电脑和智能手机显示器LED背光.本文介绍了ISL97692/3/4A主要特性,方框图,应用电路图和PCB布局图.

　　The ISL97692, ISL97693, ISL97694A are Intersil’s highly integrated 4- and 6-channel LED drivers for display backlighting . These parts maximize battery life by featuring only 1mA quiescent current, and by operating down to 2.4V input voltage, with no need for higher voltage supplies.

　　The ISL97692 has 4 channels and provides 8-bit PWM dimming with adjustable dimming frequency up to 30kHz. The ISL97693 has 6 channels with Direct PWM dimming control.

　　The ISL97694A has 6 channels and provides 8-, 10-, or 12-bit PWM dimming with adjustable dimming frequency up to 30kHz, 7.5kHz, or 1.875kHz, respectively, controlled with I2C or PWM input.

　　ISL97692 and ISL97694A feature phase shifting that may be enabled optionally, with a phase delay between channels optimized for the number of active channels. In ISL97694A, phase shifting can multiply the effective dimming frequency by 6 allowing above-audio PWM dimming with 10-bit dimming resolution.

　　The ISL97692/3/4A employ adaptive boost architecture, which keeps the headroom voltage as low as possible to maximize battery life while allowing ultra low dimming duty

　　cycle as low as 0.005% at 100Hz dimming frequency in Direct PWM mode.

　　The ISL97692/3/4A incorporate extensive protection functions including string open and short circuit detections, OVP, and OTP.

　　The ISL97692/3 are offered in the 16 Ld 3mmx3mm TQFN package and ISL97694A is offered in the 20 Ld 3mmx4mm TQFN package. All parts operate in ambient temperature

　　range of -40℃ to +85℃.

　　ISL97692/3/4A主要特性:

　　• 2.4V Minimum Input Voltage, No Need for Higher Voltage Supplies

　　• 4 Channels, up to 40mA Each (ISL97692) or 6 Channels, up to 30mA Each (ISL97693/4A)

　　• 90% Efficient at 6P5S, 3.7V and 20mA (ISL97693/4A)

　　• Low 0.8mA Quiescent Current

　　• PWM Dimming Control with Internally Generated Clock

　　- 8-bit Resolution with Adjustable Dimming Frequency up to 30kHz (ISL97692/4A)

　　- 12-bit Resolution with Adjustable Dimming Frequency up to 1.875kHz (ISL97694A)

　　- Optional Automatic Channel Phase Shift (ISL97692/4A)

　　- Linear Dimming from 0.025%~100% up to 5kHz or 0.4%~100% up to 30kHz (ISL97692/4A)

　　• Direct PWM Dimming with 0.005% Minimum Duty Cycle at 100Hz

　　• ±2.5% Output Current Matching

　　• Adjustable Switching Frequency from 400kHz to 1.5MHz

　　ISL97692/3/4A应用:

　　• Tablet, Notebook PC and Smart Phone Displays LED Backlighting

　　图1.ISL97692框图

　　图2.ISL97693框图

　　图3.ISL97694A 框图

　　图4.ISL97692典型应用电路

　　图5.ISL97693典型应用电路

　　图6.ISL97694A典型应用电路

　　图7.输入电压高达26V的LED驱动电路