AS3691 austria micro systems product brief www.austriamicrosystems.com revision 1.2 1 - 3 1 general description the AS3691 features four high precision current sources for driving up to four led strings (rgb or single color leds). each of the four currents sour ces can be controlled independently by pwm inputs. the full scale current value is set by external resistors. 2 key features 4 x 400ma constant current outputs programmable with external resistors 4 independent pwm inputs absolute current accuracy +/-0.5% ? automatic supply regulation? to reduce power dissipation 1) 1) patent pending very wide output voltage current source voltage compliance ? down to 0.41v ? up to 15v 2) integrated overtemperature protection separate sense pads (rfb1-rfb4) for easy and precise pcb layout package ? die ? qfn24 4x4mm 2) 15v is sufficient for most applications as the AS3691 dose not switch off the led current completely 3 applications general lighting backlighting rgb backlighting for lcd tv/monitors with white color balancing 4 application diagrams figure 1 ? application diagram of AS3691 for single color lighting (single module shown) product brief AS3691 4 precision 400ma current sources for rgb and singl e color leds vss vss vdd vdd ri1 ri2 ri3 ri4 rvdd cvdd 100nf uv uv pw m pwm ref overtemp AS3691 t1 t2 t3 t4 d1 r1 r2 r3 r4 vreg vss on1 on2 on3 on4 curr1 curr2 curr3 curr4 res1 res2 res3 res4 i1 uv1 vc uv2 uv3 uv4 i2 i3 i4 vc vc vc rfb1 rfb2 rfb3 rfb4 15 22 1 20 17 10 13 8 5 21,pad 23 2 24 16 19 18 14 11 12 4 7 6 csup 100nf
AS3691 austria micro systems product brief www.austriamicrosystems.com revision 1.2 2 - 3 figure 2 ? application diagram of AS3691 for rgb lighting (single module shown) figure 3 ? complete AS3691 application using white leds vss vss vddr vddr ri1 ri2 ri3 ri4 rvdd uvr uvr uvb uvb uvg uvg pwmr pwmr pwmb pwmb pwmg pwmg vddb vddb vddg vddg ref overtemp AS3691 t1 t2 t3 t4 d1 r1 r2 r3 r4 vreg vss on1 on2 on3 on4 curr1 curr2 curr3 curr4 res1 res2 res3 res4 i1 uv1 vc uv2 uv3 uv4 i2 i3 i4 vc vc vc rfb1 rfb2 rfb3 rfb4 15 22 1 20 17 10 13 8 5 21,pad 23 2 24 16 19 18 14 11 12 4 7 6 cvdd 100nf uv vdd voltage feedback input for dcdc dcdc converter for vdd overtemp AS3691 d1 vc vc vc vc ... ... ... main supply pwm vss pwm (optional) 5v powered system (optional) overtemp AS3691 d1 ...
AS3691 austria micro systems product brief www.austriamicrosystems.com revision 1.2 3 - 3 copyright copyright ? 1997-2005, austriamicrosystems ag, schlos s premstaetten, 8141 unterpremstaetten, austria- europe. trademarks registered ?. all rights reserved. the material herein may not be reproduced, adapted , merged, translated, stored, or used without the pri or written consent of the copyright owner. all products and companies mentioned are trademarks of their respective companies. disclaimer devices sold by austriamicrosystems ag are covered b y the warranty and patent identification provisions appearing in its term of sale. austriamicrosystems ag makes no warranty, express, statutory, implied, or by description regarding the information set forth her ein or regarding the freedom of the described devic es from patent infringement. austriamicrosystems ag reserves the right to change specifications and prices at a ny time and without notice. therefore, prior to designing t his product into a system, it is necessary to check with austriamicrosystems ag for current information. this product is intended for use in normal commercial applications. applications requiring extended temper ature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are spec ifically not recommended without additional processing by austri amicrosystems ag for each application. the information furnished here by austriamicrosyste ms ag is believed to be correct and accurate. howeve r, austriamicrosystems ag shall not be liable to recipi ent or any third party for any damages, including b ut not limited to personal injury, property damage, loss o f profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of an y kind, in connection with or arising out of the fu rnishing, performance or use of the technical data herein. no obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems ag rendering of t echnical or other services. contact information headquarters: austriamicrosystems ag business unit communications a 8141 schloss premst?tten, austria t. +43 (0) 3136 500 0 f. +43 (0) 3136 5692 info@austriamicrosystems.com for sales offices, distributors and representatives, please visit: www.austriamicrosystems.com a u s t r i a m i c r o s y s t e m s ? a leap ahead
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