View AL9901FDF-13_8344290.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

al9901 document number: ds37713 rev. 1 - 2 1 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 universal high voltage led driver description the al9901, high- voltage pwm led driver provides an efficient solution for offline, high-brightness led lamps for rectified line voltages ranging from 85v ac up to 305v ac . the al9901 has an internal mosfet that allows switching frequencies u p to 300khz, with the switching frequency determined by an exter nal single resistor. the al9901 topology creates a constant cu rrent through the leds providing constant light output. the output cu r rent is programmed by one external resistor. the led brightness can be varied by both linear and pwm dimming, using the al9901?s ld and pwm pins respectively. th e pwm input operates with a duty ratio of 0-100% and a frequency of up to several khz. the al9901 is available in the thermally enhanced u -dfn6040- 12 and so-16 packages. the so- 16 is compliant to high voltage spacing rules for 230vac mains applications. features ? >90% efficiency ? universal rectified 85 to 305v ac input range ? internal mosfet up to 650v, 2a ? high switching frequency up to 300khz ? internal voltage regulator removes start-up resist or ? 7.5v regulated output ? tighter current sense tolerance better than 5% ? led brightness control with linear and pwm dimming ? internal over-temperature protection (otp) ? u-dfn6040-12 and so-16 packages ? totally lead-free & fully rohs compliant (notes 1 & 2) ? halogen and antimony free. ?green? device (note 3) pin assignments u-dfn6040-12 so-16 applications ? led offline lamps ? high voltage dc-dc led driver ? signage and decorative led lighting ? back lighting of flat panel displays ? general purpose constant current source notes: 1. no purposely added lead. fully eu directi ve 2002/95/ec (rohs) & 2011/65/eu (rohs 2) complian t. 2. see http://www.diodes.com for more information about diodes incorporated?s definitions of halogen- and antimony-free, "green" and lead-free. 3. halogen- and antimony-free "green? products are defined as those which contain <900ppm bromine, <90 0ppm chlorine (<1500ppm total br + cl) and <1000ppm antimony compounds. typical applications circuit
al9901 document number: ds37713 rev. 1 - 2 2 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 pin descriptions pin name u-dfn5040-10 so-16 functions gate 1 14 gate of internal mosfet switch. nc 2 1, 2, 4, 10,16 no connection pwm 3 5 low frequency pwm dimming pin, also enable input. internal 200k pull-down to gnd v dd 4 6 internally regulated supply voltage, 7.5v nominal. can supply up to 1 ma for external circuitry. a suf ficient storage capacitor is used to provide storage when the rectified ac input is near the zer o crossing. ld 5 7 linear dimming input. changes the current limit thr eshold at current sense comparator and changes the average led current. r osc 6 8 oscillator control. a resistor connected between this pin and ground pu ts the al9901 into fixed frequency mode and sets the switching frequency. a resistor connected between this pin and gate pin puts the al9901 into fixed off-time mode and determines the off-tim e. v in 7 9 input voltage cs 8 11 senses led string and internal mosfet switc h current gnd 9 12 device ground drv 10 13 gate driver output. connect a resistor between this pin and r osc pin to put the al9901 into fixed off time mode. so 11 15 source of the internal mosfet switch sw 12 3 drain of the internal mosfet switch. ep1 ep1 na exposed pad 1(bottom). drain connection of internal power mosfet. ep2 ep2 na exposed pad 2 (bottom). substrate connection of con trol ic. connect to gnd directly underneath the package and large pcb area to minimise junction to ambient thermal impedance. functional block diagram
al9901 document number: ds37713 rev. 1 - 2 3 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 absolute maximum ratings (note 4) (@t a = +25c, unless otherwise specified.) symbol parameter ratings unit v in(max) maximum input voltage, v in , to gnd -0.5 to +520 v v cs maximum cs input pin voltage relative to gnd -0.3 t o +0.45 v v ld maximum ld input pin voltage relative to gnd -0.3 to (v dd +0.3) v v pwm_d maximum pwm_d input pin voltage relative to gnd -0.3 to (v dd +0.3) v v sw maximum mosfet drain pin voltage relative to gnd -0 .5 to +650 v v so maximum mosfet source pin voltage relative to gnd -0.5 to (v dd +0.3) v v gate maximum mosfet gate pin voltage relative to gnd -0.5 to (v dd +0.3) v v dd(max) maximum v dd pin voltage relative to gnd 8.1 v p dis continuous power dissipation (t a = +25c) - - - u-dfn6040-12 (derate 10mw/c above +25c) 1,000 mw t j junction temperature range +150 c t st storage temperature range -65 to +150 c esd hbm human body model esd protection (note 5) 2,000 v notes: 4. stresses above those listed under absolut e maximum ratings may cause permanent damage to the device. this is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational se ctions of this specification is not implied. exposu re to absolute maximum rating conditions for extende d periods may affect device reliability. all voltages are with respect to ground. curre nts are positive into, negative out of the specifie d terminal. 5. semiconductor devices are esd sensitive and may be damaged by exposure to esd events. suitable esd precautions should be taken when handling and transporting these devices maximum ratings of internal mosfet (@ t a = +25c, unless otherwise specified.) characteristic symbol value units drain-source voltage v dss 650 v gate-source voltage v gss 30 v continuous drain current (note 5) v gs = 10v steady state t c = +25c i d 1.6 1 a t c = +100c pulsed drain current (note 6) i dm 3 a avalanche current (note 7) v dd = 100v, v gs = 10v, l = 60mh i ar 0.8 a repetitive avalanche energy (note 7) v dd = 100v, v gs = 10v, l = 60mh e ar 22 mj peak diode recovery dv/dt 5 v/ns recommended operating conditions (@ t a = +25c, unless otherwise specified.) symbol parameter min max unit v indc input dc supply voltage range 15 500 v t a ambient temperature range (u-dfn6040-12) -40 +105 c t a ambient temperature range (so-16) -40 +85 - i sw switch pin output current - 0.4 a v dd maximum recommended voltage applied to v dd pin (note 6) - 8.1 v v en(lo) pin pwm_d input low voltage 0 1 v v en(hi) pin pwm_d input high voltage 2.4 v dd note: 6. when using the al9901 in isolated led lamp s, an auxiliary winding might be used.
al9901 document number: ds37713 rev. 1 - 2 4 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 electrical characteristics (@ t a = +25c, unless otherwise specified.) specifications apply to al9901 unless otherwise spe cified symbol parameter conditions min typ max unit i insd shut-down mode supply current pin pwm_d to gnd, v in = 15v - 0.5 1 ma v dd internally regulated voltage v in = v in(min) ~ 500v, (note 8) l dd(ext) = 0, gate pin open 7.2 7.5 8.1 v i dd(ext) v dd current available for external circuitry v in = 15 to 100v (note 7) - - 1.0 ma uvlo v dd under voltage lockout threshold v dd rising 6.4 6.7 7.2 v uvlo v dd under voltage lockout hysteresis v dd falling - 500 - mv r pwm_d pwm_d pull-down resistance v pwm_d = 5v 150 200 250 k v t mosfet threshold voltage i sw = 0.5a - 3 - v v fd mosfet diodes forward voltage i d = 0.5a - 0.85 - v r ds(on) drain-source on-resistance - - 4.4 - v cs(hi) current sense threshold voltage t a = -40c to +125c 237.5 250 262.5 mv f osc oscillator frequency r osc = 1m 20 25 30 khz r osc = 226k 80 100 120 d maxhf maximum oscillator pwm duty cycle f pwmhf = 25khz, at gate, cs to gnd. - - 100 % v ld linear dimming pin voltage range t a = <125c, v in = 15v 0 - 250 mv t blank current sense blanking interval v cs = 0.45v, v ld = v dd 160 250 440 ns t delay delay from cs trip to gate lo v in = 15v, v ld = 0.15, v cs = 0 to 0.22v after t blank - - 300 ns t sd thermal shut-down - - +150 - c t sdh thermal shut-down hysteresis - - +50 - ja thermal resistance junction-to-ambient u-dfn6040-12 (note 8) - 65 - c/w jc thermal resistance junction-to-case - 5 - c/w ja thermal resistance junction-to-ambient soic-16 - 100 - c/w jc thermal resistance junction-to-case - 15 - c/w notes: 7. also limited by package power dissipation capability, whichever is lower. 8. device mounted on fr-4 pcb (25mm x 25mm 1oz cop per, minimum recommended pad layout on top. for bet ter thermal performance, larger copper pad for heat-sink is needed.
al9901 document number: ds37713 rev. 1 - 2 5 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 internal mosfet characteristic symbol min typ max unit test condition off characteristics (note 9) drain-source breakdown voltage bv dss 650 ? ? v v gs = 0v, i d = 250 a zero gate voltage drain current i dss ? ? 1 a v ds = 650v, v gs = 0v gate-source leakage i gss ? ? 100 na v gs = 30v, v ds = 0v on characteristics (note 9) gate threshold voltage v gs(th) 3 ? 5 v v ds = v gs , i d = 250 a static drain-source on-resistance r ds (on) ? 4 5 v gs = 10v, i d = 1a diode forward voltage v sd ? 0.7 1 v v gs = 0v, i s = 1a dynamic characteristics (note 10) input capacitance c iss ? 479 ? pf v ds = 25v, v gs = 0v, f = 1mhz output capacitance c oss ? 29 ? pf reverse transfer capacitance c rss ? 1.9 ? pf gate resistance r g ? 2 ? v ds = 0v, v gs = 0v, f = 1mhz total gate charge q g ? 14 ? nc v ds = 520v, v gs = 10v, i d = 2a gate-source charge q gs ? 2.5 ? nc gate-drain charge q gd ? 7.3 ? nc turn-on delay time t d(on) ? 17 ? ns v ds = 325v, v gs = 10v, r g = 25 , i d = 2.5a turn-on rise time t r ? 33 ? ns turn-off delay time t d(off) ? 31 ? ns turn-off fall time t f ? 25 ? ns body diode reverse recovery time t rr ? 174 ? ns v ds = 100v, i f = 2a, di/dt = 100a/ s body diode reverse recovery charge q rr ? 884 ? nc notes: 9. short duration pulse test used to mini mize self-heating effect. 10. guaranteed by design. not subject to production testing.
al9901 document number: ds37713 rev. 1 - 2 6 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 typical characteristics -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 -40 -15 10 35 60 85 ambient temperature (c) change in current sense threshold vs. ambient tempe rature current sense threshold (mv) 280 300 320 340 360 380 400 420 440 460 -40 -15 10 35 60 85 ambient temperature ( c) input current vs. ambient temperature v = 15v in v = 400v in input current (a) -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 -40 -15 10 35 60 85 ambient temperature (c) change in oscillation frequency vs. ambient tempera ture change in frequency (%) r = 1m osc r = 226k osc 150 200 250 300 350 400 450 85 105 125 145 165 185 205 225 245 265 input voltage (v ) 180ma led driver short circuit output current vs. i nput voltage rms short circuit output current (ma) i = 180ma led(nom) v dimming control (mv) i vs. v dimming control ld out max ld 0 10 20 30 40 50 60 70 80 90 100 0 50 100 150 200 250 300 i (%) out max i = 281ma v = 264v t = 23.5c led in a
al9901 document number: ds37713 rev. 1 - 2 7 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 typical characteristics (continued) measured using al9901ev4 140 150 160 170 180 190 200 85 105 125 145 165 185 205 225 245 265 input voltage (v ) 180ma led driver output current vs. input voltage rms i (ma) out max 18 leds 16 leds 14 leds 15 leds 17 leds 80 85 90 95 105 125 145 165 185 205 225 245 265 85 input voltage (v ) 180ma led driver efficiency vs. input voltage rms efficiency (%) 15 leds 16 leds 17 le ds 18 le ds 14 leds 0.7 0.75 0.8 0.85 0.9 0.95 85 105 125 145 165 185 205 225 245 265 in put voltage (v ) 180ma led driver power factor vs. input voltage rms power factor 18 leds 17 leds 16 leds 15 leds 14 leds 4 6 8 10 12 85 105 125 145 165 185 205 225 245 265 input voltage (v ) 180ma led driver input power dissipation vs. input voltage rms power (w) 14 leds 15 leds 16 leds 17 leds 18 leds
al9901 document number: ds37713 rev. 1 - 2 8 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 typical characteristics (cont.) measured using internal mosfet typical output characteristics typical transfer characteristics typical on-resistance vs. drain current and gate voltage typical transfer characteristics typical on-resistance vs. drain current and temperature on-resistance variation with temperature v , drain-source voltage (v) figure 1 typical output characteristics ds i , drain current (a) d 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0 1 2 3 4 5 6 v = 5.0v gs 7 8 9 10 v = 5.5v gs v = 6.0v gs v = 20v gs v = 10v gs v = 8.0v gs v , gate-source voltage (v) gs figure 2 typical transfer characteristics i , drain current (a) d 0.001 0.01 0.1 1 10 0 1 2 3 4 5 6 7 8 v = 20v ds t = 85c a t = 125c a t = 150c a t = 25c a t = -55c a i , drain-source current (a) d figure 3 typical on-resistance vs. r , drain-source on-resistance ( ) ds(on) 3 3.2 3.4 3.6 3.8 4 4.2 4.4 4.6 4.8 5 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 v = 10v gs v , gate-source voltage (v) gs figure 4 typical transfer characteristics r , drain-source on-resistance ( ) ds(on) 0 2 4 6 8 10 12 14 16 18 20 4 6 8 10 12 14 16 18 20 i = 1.0a d i , drain current (a) d r , drain-source on-resistance ( ) ds(on) 0 3 6 9 12 15 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 t = -55c a t = 25c a t = 85c a t = 125c a t = 150c a v = 10v gs t , junction temperature ( c) figure 6 on-resistance variation with temperature j r , drain-source on-resistance (normalized) ds(on) 0 0.5 1 1.5 2 2.5 3 -50 -25 0 25 50 75 100 125 150 v = v i = 1a gs d 10 v = v i = 2a gs d 20
al9901 document number: ds37713 rev. 1 - 2 9 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 on-resistance variation with temperature gate threshold variation vs. ambient temperature diode forward voltage vs. current typical junction capacitance gate charge soa, safe operation area t , junction temperature ( c) j r , d r a i n - s o u r c e o n - r e s i s t a n c e ( ) ds(on) 0 3 6 9 12 15 -50 -25 0 25 50 75 100 125 150 v = v i = 2a gs d 20 v = v i = 1a gs d 10 t , junction temperature ( c) j v , g a t e t h r e s h o l d v o l t a g e ( v ) gs(th) 2 2.5 3 3.5 4 4.5 5 -50 -25 0 25 50 75 100 125 150 i = 1ma d i = 250a d v , source-drain voltage (v) sd i , source current (a) s 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 0.3 0.6 0.9 1.2 1.5 t = 150c a t = 125c a t = 85c a t = -55c a t = 25c a v , drain-source voltage (v) ds c , junction capacitance (pf) t 1 10 100 1000 0 5 10 15 20 25 30 35 40 f = 1mhz c iss c oss c rss q (nc) g , total gate charge figure 11 gate charge v gate threshold voltage (v) gs 0 2 4 6 8 10 0 2 4 6 8 10 12 14 16 v = 520v i = a ds d 2 v , drain-source voltage (v) ds i , drain current (a) d 0.001 0.01 0.1 1 10 1 10 100 1000 r limited ds(on) t = 150c t = 25c v = 10v single pulse j(max) a gs dut on 1 * mrp board dc p = 10s w p = 1s w p = 100ms w p = 10ms w p = 1ms w p = 100s w
al9901 document number: ds37713 rev. 1 - 2 10 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 led current vs. duty cycle by pwm dimming when vin is 120vac led current vs. duty cycle by pwm dimming when vin is 230vac
al9901 document number: ds37713 rev. 1 - 2 11 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 applications information the al9901 is capable of operating in isolated or n on-isolated topologies. it can also be made to oper ate in continuous as well as discontinuous conduction mode. figure 1 functional block diagram the al9901 contains a high voltage ldo (see figure 1) the output of the ldo provides a power rail to t he internal circuitry including the gate driver. a uvlo on the output of the ldo prevents in correct operation at low input voltage to the v in pin. in a non-isolated buck led driver, when the gate pi n goes high, the internal power mosfet (q1) is turn ed on causing current to flow through the leds inductor (l1), and current sense resistor (r sense ). when the voltage across r sense exceeds the current sense pin threshold, the inter nal mosfet q1 is turned off. the energy stored in the i nductor causes the current to continue to flow thro ugh the leds via diode d1. the al9901?s ldo provides all power to the rest of the ic including gate drive, and this removes the n eed for large, high-power start-up resistors. this means that during normal operation the al9901 requires around 0.5ma from the high voltage power r ail. the ldo can also be used to supply up to 1ma to external circuits. the al9901 operates and regulates by limiting the p eak current of the internal mosfet; the peak curren t sense threshold is nominally set at 250mv. the al9901 is capable of operating in a fixe d frequency (pwm) mode and also variable frequency (fixed off-time) mode to regulate the led current. the same basic operation is true for isolated topol ogies; however in these the energy stored in the tr ansformer delivers energy to leds during the off-cycle of the internal mosfet. the on-resistance of the al9901?s internal power mo sfet means that it can drive up to 2a. design parameters setting the led current in the non-isolated buck converter topology, figure 1, the average led current is not the peak current divided by two - however, there is a certain error due to the difference between the peak and th e average current in the inductor. the following eq uation accounts for this error: ) * 5.0( 250mv r sense ripple led i i + =
al9901 document number: ds37713 rev. 1 - 2 12 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 applications information (continued) setting operating frequency the al9901 is capable of operating between 25 and 4 50 khz switching frequency range. the switching fre quency is programmed by connecting an external resistor between r osc pin and ground. the corresponding oscillator perio d is: t osc = 25 22 r osc + s with r osc in k the switching frequency is the reciprocal of the os cillator period. typical values for r osc vary from 75k to 1m in buck mode the duty cycle, d, is in leds v v ; so when driving small numbers of leds from high i nput voltages the duty cycle will be reduced and care should be taken to ensure that t on > t blank . the simplest way to do this is to reduce/limit th e switching frequency by increasing the r osc value. reducing the switching frequency will also i mprove the efficiency. when operating in buck mode the designer must keep in mind that the input voltage must be maintained h igher than two times the forward voltage drop across the leds. this limitation is related to the output current instability that may develop wh en the al9901 operates at a duty cycle greater than 0.5. this instability reveals itself as an osc illation of the output current at a sub-harmonic (sbo) of the switching frequency. inductor selection the non-isolated buck circuit, figure 1, is usually selected and it has two operation modes: continuou s and discontinuous conduction modes. a buck power stage can be designed to operate in cont inuous mode for load current above a certain level, usually 15% to 30% of full load. usually, the input voltage range, the output voltage and loa d current are defined by the power stage specificat ion. this leaves the inductor value as the only design parameter to maintain continuous conduc tion mode. the minimum value of inductor to maintai n continuous conduction mode can be determined by the following example. the required inductor value is determined from the desired peak-to-peak led ripple current in the indu ctor; typically around 30% of the nominal led current. ( ) ( ) osc led leds in f i d v v l ? = 3.0 where, d is duty cycle the next step is determining the total voltage drop across the led string. for example, when the strin g consists of 10 high-brightness leds and each diode has a forward voltage drop of 3.0v at it s nominal current; the total led voltage v leds is 30v. dimming the led brightness can be dimmed either linearly (u sing the ld pin) or via pulse width modulation (usi ng the pwm-d pin); or a combination of both - depending on the application. pulling the pw m_dpin to ground will turn off the al9901. when dis abled, the al9901?s quiescent current is typically 0.5ma (0.65 for al9901a). reducing the ld voltage will reduce the led current but it will no t entirely turn off the external power transistor and hence the led current ? this is due to the finite blanking period. only the pwm_dpin wi ll turn off the power transistor. linear dimming is accomplished by applying a 45 to 250mv analog signal to the ld pin. this overrides t he default 250mv threshold level of the cs pin and reduces the output current. if an input voltage greater than 250mv is applied to the ld the n the output current will not change. the ld pin also provides a simple cost effective so lution to soft start. by connecting a capacitor to the ld pin down to ground at initial power up, the ld pin will be held low, causing the sense thre shold to be low. as the capacitor charges up the cu rrent sense threshold will increase, thereby causing the average led current to increase. pwm dimming is achieved by applying an external pwm signal to the pwm_d pin. the led current is propor tional to the pwm duty cycle and the light output can be adjusted between 0 and 100%.the pwm signal enables and disables the al9901 - modul ating the led current. the ultimate accuracy of the pwm dimming method is limited only by the minimum gate pulse width, which is a fractio n of a percentage of the low frequency duty cycle. pwm dimming of the led light can be ach ieved by turning on and off the converter with a lo w frequency 50hz to 1000hz ttl logic level signal. with both modes of dimming it is not possible to ac hieve average brightness levels higher than the one set by the current sense threshold level of the al9901. i f a greater led current is required, then a smaller sense resistor should be used.
al9901 document number: ds37713 rev. 1 - 2 13 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 applications information (cont.) output open circuit protection the non-isolated buck led driver topology provides inherent protection against an open circuit conditi on in the led string due to the leds being connected in series with the inductor. should the l ed string become open circuit then no switching occ urs and the circuit can be permanently left in this state with damage to the rest of the circui t. ac/dc off-line led driver the al9901 is a cost-effective off-line buck led dr iver-converter specifically designed for driving le d strings. it is suitable for being used with either a rectified ac line or any dc voltage betwee n 15-500v. see figure 3 for typical circuit. figure 2 typical application circuit (without pfc) buck design equations: = d in leds v v osc on f d t = l led on leds in i 3.0 t ) v v ( ? = sense r ))3.0 i( 5.0( i 25.0 led led + where i led x 0.3 = i ripple design example for an ac line voltage of 120v the nominal rectifie d input voltage is v in = 120v x 1.41 = 169v. from this and the led chain voltage, the duty cycle can be determined: d = v leds /v in = 30/169 = 0.177 from the switching frequency, for example f osc = 50 khz, the required on-time of the internal mos fet can be calculated: t on = d/f osc = 3.5 s the value of the inductor is determined as follows: l = (v in - v leds ) x t on / (0.3 x i led ) = 4.6mh
al9901 document number: ds37713 rev. 1 - 2 14 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 applications information (cont.) input bulk capacitor for offline lamps, an input bulk capacitor is requi red to ensure that the rectified ac voltage is held above twice the led string voltage throughout the ac line cycle. the value can be calculated from : in c max _ dc l min _ line ch in v f2 v 2 ) d 1( p ? ? where: ch d : capacity charge work period, generally about 0.2~0.25 l f : input frequency for full range (85~265v rms ) max _ dc v ? should be set 10~15% of min _ line v 2 if the capacitor has a 15% voltage ripple, then a s implified formula for the minimum value of the bulk input capacitor approximates to: c min = 2 in leds led v 0.06 v i power factor correction if power factor improvement is required, then for t he input power less than 25w, a simple method for i mproving the power factor can be implemented by potential dividing down the rectifie d mains voltage (resistors r1 and r2 in figure 4) a nd feeding it into the ld pin. the current drawn from the supply voltage will follow an approx imate half sine wave. a filter across the leds redu ces the potential for flicker. this circuit also significantly reduces the size of input capacitors. figure 3 typical application circuit with simple pf c passive power factor correction using three high vo ltage diodes and two identical capacitors can be im plemented. for further design information, please see an75 from the diodes website. dc-dc buck led driver the design procedure for an ac input buck led drive r outlined in the previous chapters equally applies to dc input led drivers.
al9901 document number: ds37713 rev. 1 - 2 15 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 applications information (cont.) dc-dc boost led driver due to the topology of the al9901 led driver-conver ter, it is capable of being used in boost configura tions ? at reduced accuracy. the accuracy can be improved by measuring the led current with a n op amp and use the op amp?s output to drive the l d pin. a boost led driver is used when the forward voltage drop of the led string is higher than the input su pply voltage. for example, the boost topology can be appropriate when input voltage is s upplied by a 48v power supply and the led string co nsists of twenty hb leds, as the case may be for a street light. figure 4 boost led driver in a boost converter, when the internal mosfet is o n the energy is stored in the inductor which is the n delivered to the output when the internal mosfet switches off. if the energy stored in the in ductor is not fully depleted by the next switching cycle (continuous conduction mode), the dc conversion between input and output voltage is give n by: d 1 v v in out ? = out in out v v v d ? = from the switching frequency, f osc , the on-time of the mosfet can be calculated: osc on f d t = from this the required inductor value can be determ ined by: led on in i 3.0 t v l ? ? = the boost topology led driver requires an output ca pacitor to deliver current to the led string during the time that the internal mosfet is on. in boost led driver topologies, if the leds should become open circuit, damage may occur to the power switch and so some form of detection should be present to provide overvoltage detection/ protection.
al9901 document number: ds37713 rev. 1 - 2 16 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 ordering information part number v cs tolerance package code packaging 13? tape and reel quantity part number suffix AL9901FDF-13 5% fdf u-dfn6040-12 3,000/tape & reel -13 al9901s16-13 5% s16 so-16 2,500/tape & reel -13 marking information pkg p/n marking code soic-16l al9901s16-13 al9901 dfn6040-12 AL9901FDF-13 al9901
al9901 document number: ds37713 rev. 1 - 2 17 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 package outline dimensions (all dimensions in mm.) please see ap02002 at http://www.diodes.com/datashe ets/ap02002.pdf for the latest version. (1) u-dfn6040-12 (2) so-16 u - dfn6040 - 12 dim min max typ a 0.55 0.65 0.60 a1 0 0.05 0.02 a3 - - 0.15 b 0.35 0.45 0.40 d 5.95 6.05 6.00 d1 1.95 2.15 2.05 d2 2.35 2.55 2.45 e - - 1.00 e 3.95 4.05 4.00 e1 2.10 2.30 2.20 e2 1.80 2.00 1.90 l 0.35 0.45 0.40 z - - 0.30 all dimensions in mm so - 16 dim min max a 1.40 1.75 a1 0.10 0.25 a2 1.30 1.50 b 0.33 0.51 c 0.19 0.25 d 9.80 10.00 e 3.80 4.00 e 1.27 typ h 5.80 6.20 l 0.38 1.27 ? 0 8 all dimensions in mm a 3 a 1 seating plane d e e l b z a d1 e1 d2 e 2 d e h l a2 b e a1 a c detail ?a? detail ?a? gauge plane
al9901 document number: ds37713 rev. 1 - 2 suggested pad layout please see ap02001 at http://www.diodes.com/datasheets/ap02001 .pdf for the latest version. (1) u-dfn6040-12 (2) so-16 taping orientation the taping orientation of the other package type ca n be found on our website at http://www.diodes.com/ datasheets/ap02007.pdf. (1) u-dfn6040-12 (2) soic-16 x 3 x1 c x pin1 x 2 y1 x 1 x c y 1 pin 1 18 of 20 www.diodes.com ap02001 at http://www.diodes.com/datasheets/ap02001 .pdf for the latest version. the taping orientation of the other package type ca n be found on our website at http://www.diodes.com/ datasheets/ap02007.pdf. dimensions (in mm) c g g1 x x1 x2 x3 y y1 y2 y3 dimensions c x x1 y y1 y 2 y 3 y g1 g y march 2015 ? diodes incorporated al9901 the taping orientation of the other package type ca n be found on our website at http://www.diodes.com/ datasheets/ap02007.pdf. value (in mm) 0.500 0.650 0.350 0.250 1.075 1.275 2.750 0.400 1.150 1.000 2.300 value (in mm) 1.270 0.670 9.560 1.450 6.400
al9901 document number: ds37713 rev. 1 - 2 19 of 20 www.diodes.com march 2015 ? diodes incorporated al9901
al9901 document number: ds37713 rev. 1 - 2 20 of 20 www.diodes.com march 2015 ? diodes incorporated al9901 important notice diode incorporated makes no warranty of any kind, e xpress or implied, with regards to this document, including, but not limited to, the implied warranti es of merchantability and fitness for a particular purpose (and their equivalents under the laws of any jurisd iction). diodes incorporated and its subsidiaries reserve th e right to make modifications, enhancements, improv ements, corrections or other changes without further notice to this document and any pro duct described herein. diodes incorporated does not assume any liability arising 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 cu stomer or user of this document or products describ ed herein in such applications shall assume all risks of such use and will agree to hold diodes incorporated and all the companies whose products are represented on diodes incorporated website, harmless against all damages. diodes incorporated does not warrant or accept any liability whatsoever in respect of any products pur chased through unauthorized sales channel. should customers purchase or use diodes incorporate d products for any unintended or unauthorized appli cation, customers shall indemnify and hold diodes incorporated and its representatives ha rmless against all claims, damages, expenses, and a ttorney fees arising out of, directly or indirectly, any claim of personal injury or death a ssociated with such unintended or unauthorized appl ication. products described herein may be covered by one or more united states, international or foreign patent s pending. product names and markings noted herein may also be covered by one or more uni ted states, international or foreign trademarks. this document is written in english but may be tran slated into multiple languages for reference. only the english version of this document is the final and determinative format released by diodes i ncorporated. life support diodes incorporated products are specifically not a uthorized for use as critical components in life su pport devices or systems without the express written approval of the chief executive officer of diodes incorporated. as used herein: a. life support devices or systems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to per form when properly used in accordance with instruct ions 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 lif e support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affe ct its safety or effectiveness. customers represent that they have all necessary ex pertise in the safety and regulatory ramifications of their life support devices or systems, and acknowledge and agree that they are solely responsi ble for all legal, regulatory and safety-related re quirements concerning their products and any use of diodes incorporated products in such safety- critical, life support devices or systems, notwiths tanding any devices- or systems-related information or support that may be provided by diod es incorporated. further, customers must fully ind emnify diodes incorporated and its representatives against any damages arising out of the use of diodes incorporated products in such saf ety-critical, life support devices or systems. copyright ? 2015, diodes incorporated www.diodes.com

▲Up To Search▲

Price & Availability of AL9901FDF-13

	To Download AL9901FDF-13 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .