IntersilISL97694A單個鋰電池六路LED驅(qū)動方案

作者：時間：2012-08-13 來源：網(wǎng)絡(luò)

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Intersil公司的ISL97692/3/4A是單個鋰電池驅(qū)動的4四/六路LED驅(qū)動器,靜態(tài)電流僅為1mA,輸入電壓可低至2.4V.ISL97692是四路,提供8位PWM調(diào)光,可調(diào)頻率高達(dá)30kHz, ISL97693是六路,Direct PWM調(diào)光控制,ISL97694A是六路,提供8/10/12位PWM調(diào)光,可調(diào)頻率分別是30kHz,7.5kHz或1.875kHz.主要用于平板電腦,筆記本電腦和智能手機(jī)顯示器LED背光.本文介紹了ISL97692/3/4A主要特性,方框圖,應(yīng)用電路圖和PCB布局圖.

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應(yīng)用:

? Tablet, Notebook PC and Smart Phone Displays LED Backlighting