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AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 1 of 12 www.diodes.com june 2012 ? diodes incorporated advance information description the AL5801 combines a 100v n-channel mosfet with a pre- biased npn transistor to make a si mple, small footprint led driver. the led current is set by an external resistor connected from r ext pin (4) to gnd pin (6). the intern al pre-biased transistor develops approximately 0.56v across the external resistor. the AL5801 open-drain output can operate from 1.1v to 100v enabling it to operate 5v to 100v power supplies without additional components. pwm dimming of the led current can be achieved by driving the bias pin (1) with an external, open-collector npn transistor or open-drain n-channel mosfet. the AL5801 is available in a sot26 package and is ideal for driving led currents up to 350ma. pin assignments (top view) sot26 features ? feedback pin reference voltage v rset = 0.56v at +25oc ? -40 to +125oc temperature range ? 1.1v to 100v open-drain output ? negative temperature v rset co-efficient automatically reduces the led current at high temperatures ? lead-free finish; rohs compliant (notes 1 & 2) ? halogen and antimony free. ?green? device (note 3) ? low thermal impedance sot26 package with copper lead frame applications ? linear led drivers ? led signs ? offline led luminaries notes: 1. eu directive 2002/95/ec (rohs) & 2011/65/eu (roh s 2) compliant. all applicable rohs exemptions applied. 2. see http://www.diodes.com for more in formation about diodes incorpor ated?s definitions of halogen- and antimony-free, "gree n" and lead-free. ? 3. halogen- and antimony-free "green? products are defined as those which contain <900ppm br omine, <900ppm chlorine (<1500ppm t otal br + cl) and <1000ppm antimony compounds. typical application circuit r ext www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 2 of 12 www.diodes.com june 2012 ? diodes incorporated advance information pin description pin number name function 1 bias biases the open-drain output mosfet 2 fb feedback pin 3 out open-drain led driver output 4 r ext current sense pin. led current sensing resi stor should be connected from here to gnd 5 comp compensation pin. connect comp pin to rext pin and insert a 1nf ceramic capacitor from comp pin to fb pin for improved transient stability 6 gnd ground reference point for setting the led current functional block diagram figure 1 block diagram absolute maximum ratings symbol characteristics values unit v out output voltage relative to gnd 100 v v bias bias voltage relative to gnd (note 4) 20 v v fb fb voltage relative to gnd 6 v v comp comp voltage relative to gnd 6 v v rext rext voltage relative to gnd 6 v i out output current 350 ma t j operating junction temperature -40 to +150 c t st storage temperature -55 to +150 c these are stress ratings only. operation outside the abs olute maximum ratings may cause device failure. operation at the absolute maximum rating for ex tended periods may reduce device reliability. notes: 4. with pins 5 and 6 connected together www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 3 of 12 www.diodes.com june 2012 ? diodes incorporated advance information package thermal data characteristic symbol value unit power dissipation (note 5) @ t a = 25c p d 0.75 w power dissipation (note 6) @ t a = 25c 0.70 power dissipation (note 7) @ t a = 25c 0.85 power dissipation (note 8) @ t a = 25c 1.05 thermal resistance, junction to ambient air (note 5) @ t a = 25c r ja 165 c/w thermal resistance, junction to ambient air (note 6) @ t a = 25c 180 thermal resistance, junction to ambient air (note 7) @ t a = 25c 145 thermal resistance, junction to ambient air (note 8) @ t a = 25c 120 notes: 5. device mounted on 15mm x 15mm 2oz copper board. 6. device mounted on 25mm x 25mm 1oz copper board. 7. device mounted on 25mm x 25mm 2oz copper board. 8. device mounted on 50mm x 50mm 2oz copper board. recommended operating conditions symbol parameter min max unit v bias supply voltage range 3.5 20 v v out out voltage range 1.1 100 i led led pin current (note 9) 25 350 ma t a operating ambient temperature range -40 125 c notes: 9. subject to ambient temperature, power dissipation and pcb. nmosfet electrical ch aracteristics: (q1) (@t a = +25c unless otherwise specified) characteristic symbol min typ max unit test condition off characteristics drain-source breakdown voltage bv dss 100 ? ? v v gs = 0v, i d = 250 a zero gate voltage drain current i dss ? ? 1 a v ds = 60v, v gs = 0v gate-source leakage i gss ? ? 100 na v gs = 20v, v ds = 0v on characteristics gate threshold voltage v gs ( th ) 2.0 ? 4.1 v v ds = v gs , i d = 250 a static drain-source on-resistance r ds (on) ? ? ? 0.85 0.99 v gs = 10v, i d = 1.5a v gs = 6v, i d = 1a forward transconductance g fs ? 0.9 ? s v ds = 15v, i d = 1a diode forward voltage v sd ? 0.89 1.1 v v gs = 0v, i s = 1.5a dynamic characteristics input capacitance c iss ? 129 ? pf v ds = 50v, v gs = 0v f = 1.0mhz output capacitance c oss ? 14 ? pf reverse transfer capacitance c rss ? 8 ? pf www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 4 of 12 www.diodes.com june 2012 ? diodes incorporated advance information pre-bias transistor electrical characteristics: (q2) (@t a = +25c unless otherwise specified) characteristic (note 10) symbol min typ max unit test condition input voltage v i ( off ) 0.4 - - v v cc = 5v, i o = 100 a v i ( on ) - - 1.5 v v cc = 0.3v, i o = 5ma output voltage v o ( on ) - 0.05 0.3 v i o /i i = 5ma/0.25ma output current i o ( off ) - - 0.5 a v cc = 50v, v i = 0v dc current gain g 1 80 - - - v o = 5v, i o = 10ma input resistance r 1 3.2 4.7 6.2 k ? - resistance ratio r 2 /r 1 8 10 12 - - notes: 10. short duration pulse test used to minimize self-heating effect. thermal characteristics 0.2 0.4 0.6 0.8 1.2 0255075100125150 temperature (c) figure 2 derating curve m ax p o we r d issi p a t i o n (w) 1.0 0 50mm x 50mm (2oz. fr4) 25mm x 25mm (2oz. fr4) 15mm x 15mm (2oz. fr4) 0.2 0.4 0.6 0.8 1.2 0 500 1,000 1,500 2,000 2,500 copper area (mm ) figure 3 area vs. max power 2 max p o we r dissi p a t i o n (w) t = 25c 2oz. fr4 a 1.0 0 100 120 140 160 180 0.0001 0.001 0.01 0.1 1 10 100 1,000 pulse width (s) figure 4 transient thermal impedance j u n c t i o n t o ambie n t ai r thermal resistance (c/w) t = 25c 25mm x 25mm 1oz. fr4 a 80 60 40 20 0 d = 0.05 d = 0.1 single pulse d = 0.2 d = 0.5 www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 5 of 12 www.diodes.com june 2012 ? diodes incorporated advance information typical performance characteristics 0.05 0.15 0.25 0.35 01 23 v (v) out figure 5 output current vs. v out i (a) out 0 0.10 0.20 0.30 0.40 i = 0.1ma bias r = 1.6 ext r = 3.75 ext r = 11.6 ext r = 22.7 ext 100 150 200 250 300 350 400 11 01 0 0 r () ext figure 6 output current vs. r ext i (ma) out 50 0 i = 0.1ma bias 0.1 0.2 0.3 0.4 0.5 01 23 v (v) out figure 7 output current vs. v out i (a) out 0 i = 0.1ma r = 1.6 bias ext t = -40c a t = 25c a t = 85c a 0.05 0.15 02 4 6 810 v (v) out figure 8 output current vs. v out 0 0.10 0.20 i (a) out i = 0.1ma r = 3.75 bias ext t = -40c a t = 25c a t = 85c a 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0 5 10 15 v (v) out figure 9 output current vs. v out 0 i (a) out i = 0.1ma r = 11.6 bias ext t = -40c a t = 25c a t = 85c a 0.005 0.015 0.025 0.035 0 5 10 15 20 v (v) out figure 10 output current vs. v out 0 0.010 0.020 0.030 i (a) out i = 0.1ma r = 22.7 bias ext t = -40c a t = 25c a t = 85c a www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 6 of 12 www.diodes.com june 2012 ? diodes incorporated advance information typical performance characteristics 100 200 300 400 500 600 700 800 -50 0 50 100 150 junction temperature ( c) figure 11 v vs. junction temperature rext v (mv) rext i = 0.1ma v bias bias = 5v 0 0 50 100 150 200 250 300 350 400 11 01 0 0 v (v) out figure 12 output current vs. v out i (ma) out i = 0.1ma t = 85c bias a 50mm x 50mm (2oz. fr4) 25mm x 25mm (2oz. fr4) 15mm x 15mm (2oz. fr4) www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 7 of 12 www.diodes.com june 2012 ? diodes incorporated advance information application information figure 13 typical application circuit for linear mode current sink led driver the AL5801 is designed for drivi ng high brightness leds with typical led current up to 350ma. it provides a more cost effective way for driving low current leds when compared against more complex switching regulator solutions. furthermore, it reduces the pcb board area of the solution because there is no need for external components like inductors, capacitors and/or switching diodes. figure 13 shows a typical applicati on circuit diagram for driving an led or a string of leds. the np n transistor q2 measures the led current by sensing the voltage across an external resistor r ext . q2 uses its v be as reference to set the voltage across r ext and controls the gate voltage of mosfet q1. q1 operates in linear mode to regulate the led current. the led current is i led = v rset / r ext where v rset is the v be of q2. v be is 0.56v typical at a 25oc device temperature. see figure 11 for the variation of v be with q2?s junction temperature at i bias = 0.1ma. v be has a negative temperature coefficient which reduces the led current as the device warms up, protecting the led(s). r bias should be chosen to drive 0.1ma current into the bias pin r bias = ( v cc ? 3.75v ) / 0.1ma from the above equation, for any required led current the necessary external resistor r ext can be calculated from r ext = v rset / i led the expected linear mode power dissipation must be factored into the design consideration. the po wer dissipation across the device can be calculated by taking the maximum supply voltage less the minimum voltage across the led string. v ds(q1) = v cc(max) ? v led(min) ? v rset p d = v ds(q1) * i led as the output led current of AL5801 increases so will its power dissipation. the power dissi pation will cause the device temperature to rise above ambient, t a , by an amount determined by the package thermal resistance, r ja . therefore, the power dissipati on supported by the device is dependent upon the pcb board material, the copper area and the ambient temperature. the maximum dissipation the device can handle is given by: p d = ( t j(max) - t a ) / r ja t j(max) = 150oc is the maximum device junction temperature. refer to the thermal characteristic graphs in figure 2 to 4 for selecting the appropriate pcb copper area. figure 12 shows the current capabilities of the AL5801 at 25oc with different pcb copper area heat sinks. www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 8 of 12 www.diodes.com june 2012 ? diodes incorporated advance information constant led current temperature compensation variation in the junction temperatur e of q2 will cause variations in the value of controlled led current i led . the base-emitter v be voltage of q2 decreases with increasing temperature at a rate of approximately 2mv/ oc . figure 14 shows a simple temperature compensation network, which comprises of an ntc thermistor and resistor r base , for stabilizing the led current. figure 14 constant led current temperature compensation for AL5801 the voltage drop v rset in the sense resistor r ext should be set to be 40 to 100mv higher than the v be(q2) at 25oc . figure 11 shows the typical v be(q2) is 0.56v at room temperature with 0.1ma i bias , so v rset is selected to be 0.62v. with the v rset chosen, the sense resistor value for 350ma i led is determined by r ext = v rset / i led = 0.62v / 350ma = 1.77 ? so a standard resistor value of 1.78? with 1% tolerance is used. the r th resistance of the ntc thermistor at room temperature is recommended as 10k ? . the value of base resistor r base is set to be 470 ? . q2?s base current is obtained as i b(q2) = ( v rset - v be(q2) ) / r base - v be(q2) / r th = ( 0.62v - 0.56 ) / 470 ? - 0.56v / 10k ? = 72a when v be(q2) is changed to v be t as the temperature increases to t oc , the thermistor resistance at t oc required to compensate this variation is given by r th t = v be t / (( v rset - v be t ) / r base - i b(q2) ) at - 2mv/ oc, v be(q2) reduces to 0.44v from 0.56v as the temperature increases from 25oc to 85oc. from the above equation, the thermistor?s resistance at 85oc to keep the same output current is given by r th 85 = 0.44v / (( 0.62v ? 0.44v ) / 470 ? - 72ua ) = 1.4k ? the ntc thermistor is chosen for compensation whose resistance is 10k ? at 25oc and 1.38k ? at 85oc with a value of 3530 . figure 15 shows the i led variation with temperature with and without temperature compensation. figure 15 led current variation with and without temperature compensation www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 9 of 12 www.diodes.com june 2012 ? diodes incorporated advance information pwm dimming (a) (b) figure 16 application circuits for led driver with pwm dimming functionality (a) mosfet driving and (b) transistor driving pwm dimming can be achieved by dr iving the bias pin (1). an external open-collector npn transistor or open-drain n-channel mosfet can be used to drive th e bias pin as shown in figure 16. dimming is achieved by turnin g the leds on and off for a portion of a single cycle. the pw m signal can be provided by a micro-controller or by analog circuitry. figure 17 shows the led current against the pwm signal duty ratio when the AL5801 is used to drive three series connected leds from a 12v supply. the pwm dimming frequency is set to 200hz. the pwm signal is supplied to the open-drain small signal mosfet?s gate as shown in figur e 16a. the bias pin signal is an inversion of the pwm drive to the mosfet?s gate. therefore, a pwm signal duty cycle of 0% provides the maximum led current. sufficiently large pcb copper area is used for heat sinking of the AL5801 in order to minimize the device self-heating at 25oc ambient. figure 17 led current against pwm dimming signal duty ratio at 200hz pwm frequency www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 10 of 12 www.diodes.com june 2012 ? diodes incorporated advance information ordering information (note 11) device package code packaging (note 11) 7? tape and reel quantity part number suffix AL5801w6-7 w6 sot26 3,000/tape & reel -7 notes: 11. for packaging details, go to our website at http://www.diodes.com marking information date code key year 2012 2013 2014 2015 2016 2017 2018 code z a b c d e f month jan feb mar apr may jun jul aug sep oct nov dec code 1 2 3 4 5 6 7 8 9 o n d l100 = product type marking code ym = date code marking y = year (ex: y = 2012) m = month (ex: 9 = september) green www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 11 of 12 www.diodes.com june 2012 ? diodes incorporated advance information package outline dimensions suggested pad layout sot26 dim min max typ a 0.35 0.50 0.38 b 1.50 1.70 1.60 c 2.70 3.00 2.80 d ? ? 0.95 h 2.90 3.10 3.00 j 0.013 0.10 0.05 k 1.00 1.30 1.10 l 0.35 0.55 0.40 m 0.10 0.20 0.15 0 8 ? all dimensions in mm dimensions value (in mm) z 3.20 g 1.60 x 0.55 y 0.80 c1 2.40 c2 0.95 a m j l d b c h k x z y c1 c2 c2 g www.datasheet.net/ datasheet pdf - http://www..co.kr/
AL5801 100v, adjustable current sink linear led driver AL5801 document number: ds35555 rev. 2 - 2 12 of 12 www.diodes.com june 2012 ? diodes incorporated advance information important notice diodes incorporated makes no warranty of any kind, express or implied, with regards to this document, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose (and their equivalents under the laws of any jurisdiction). diodes incorporated and its subsidiaries rese rve the right to make modifications, enhanc ements, improvements, corrections or ot her changes without further notice to this document and any product described herein. diodes incorporated does not assume any liability ari sing out of the application or use of this document or any product described herein; neither does diodes incorporated convey any license under its patent or trademark rights, nor the rights of others. any customer or us er of this document or products described herein in such applica tions shall assume all risks of such use and will agree to hold diodes in corporated and all the companies w hose products are represented on diodes incorporated website, harmless against all damages. diodes incorporated does not warrant or accept any liability what soever in respect of any pr oducts purchased through unauthoriz ed sales channel. should customers purchase or use diodes in corporated products for any unintended or unauthorized application, customers shall i ndemnify and hold diodes incorporated and its representatives harmless agai nst all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. products described herein may be covered by one or more united states, international or foreign patents pending. product names and markings noted herein may also be covered by one or mo re united states, international or foreign trademarks. life support diodes incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the chief executive officer of diodes incorporated. as used herein: a. life support devices or syst ems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when prop erly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. b. a critical component is any component in a life support devic e or system whose failure to perform can be reasonably expect ed to cause the failure of the life support device or to affect its safety or effectiveness. customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support dev ices or systems, and acknowledge and agree that they are solely responsible fo r all legal, regulatory and safety -related requirements concerning their products and any use of diodes incorporated products in such safety-cri tical, life support devices or systems, notwithstanding any devic es- or systems- related information or support that may be provided by diodes inco rporated. further, customers must fully indemnify diodes inc orporated and its representatives against any damages aris ing out of the use of diodes incorporated products in such safety-critical, life su pport devices or systems. copyright ? 2012, diodes incorporated www.diodes.com www.datasheet.net/ datasheet pdf - http://www..co.kr/

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