View LTC3496EUFDTRPBF_7573918.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

lt3496 1 3496f typical application features applications description triple output led driver the lt ? 3496 is a triple output dc/dc converter designed to operate as a constant-current source and is ideal for driving leds. the lt3496 works in buck, boost or buck- boost mode. the lt3496 uses a ? xed frequency, current mode architecture resulting in stable operation over a wide range of supply and output voltages. a frequency adjust pin allows the user to program switching frequency between 330khz and 2.1mhz to optimize ef? ciency and external component size. the lt3496 supports 3000:1 dimming control on each channel. each of the three regulators is independently operated by that channels pwm signal. the pwm feature allows precise adjustment of the color mixing or dimming ratio of the led source. each of the three channels has a built-in gate driver to drive an external led-disconnect p-channel mosfet, allowing high dimming range. the output current range of each channel of the lt3496 is programmed with an external sense resistor. the ctrl pin is used to adjust the led current either for analog dimming or overtemperature protection. true color pwm tm dimming delivers up to 3000:1 dimming ratio built-in gate driver for pmos led disconnect three independent driver channels with 750ma, 45v internal switches operates in buck, boost, buck-boost modes ctrl pin accurately sets led current sense threshold over a range of 10mv to 100mv adjustable frequency: 330khz to 2.1mhz open led protection wide input voltage range: operation from 3v to 30v transient protection to 40v surface mount components 28-lead (4mm 5mm) qfn package rgb lighting billboards and large displays automotive and avionic lighting constant-current sources high dimming ratio triple output led power supply , lt, ltc and ltm are registered trademarks of linear technology corporation. all other trademarks are the property of their respective owners. patent pending. 3000:1 pwm dimming at 120hz 0.5a 0.47 f 0.47 f led1 200m ? 200m ? tg1 pv in 42v 7 leds 10 h cap1 0.5a led2 tg2 10 h cap2 0.5a 0.47 f led3 1 f 3 200m ? 0.1 f 3496 ta01a tg3 10 h cap3 sw1 sw2 lt3496 gnd sw3 tg1-3 vc1-3 v ref ctrl1-3 fadj ovp1-3 cap1-3 led1-3 v in pwm1-3 shdn pwm1-3 shdn v in 3v to 24v 1 f pwm 5v/div 0.5 s/div 3496 ta01b i led 0.5a/div i l 0.5a/div
lt3496 2 3496f electrical characteristics absolute maximum ratings v in (note 4) ...............................................................40v sw1-sw3, led1-led3, cap1-cap3 ........................45v tg1-tg3 ............................................ cap C 10v to cap pwm1-pwm3 ...........................................................20v v ref , ctrl1-ctrl3, fadj, vc1-vc3, ovp1-ovp3 ..2.5v shdn ........................................................................40v operating junction temperature range (note 2) .................................................. C40c to 125c max junction temperature .................................... 125c storage temperature range ................... C65c to 150c (note 1) parameter conditions min typ max units v in operation voltage (note 4) 3 30 v v in undervoltage lockout 2.1 2.4 v full-scale led current sense voltage cap1-3 = 24v 98 97 100 103 104 mv mv one-tenth scale led current sense voltage ctrl1-3 = 100mv, cap1-3 = 24v 7.5 10 12.5 mv capn/ledn operating voltage 2.5 45 v v ref output voltage i ref = 200a 1.96 2 2.04 v v ref line regulation 3v v in 40v 0.03 %/v quiescent current in shutdown ? s ? h ? d ? n = 0v 0.1 10 a quiescent current idle pwm1-pwm3 = 0v 6 7.5 ma quiescent current active (not switching) vc1-vc3 = 0v 11 14 ma the denotes the speci? cations which apply over the full operating temperature range, otherwise speci? cations are at t a = 25c. v in = 5v, v ? s ? h ? d ? n = 5v, cap1-3 = 5v, pwm1-3 = 5v, fadj = 0.5v, ctrl1-3 = 1.5v, ovp1-3 = 0v, unless otherwise noted. pin configuration 9 10 top view 29 ufd package 28-lead (4mm 5mm) plastic qfn 11 12 13 28 27 26 25 24 14 23 6 5 4 3 2 1 pwm1 v ref ctrl3 ctrl2 ctrl1 fadj vc3 vc2 cap3 sw3 sw2 cap2 led2 tg2 sw1 cap1 pwm2 pwm3 shdn v in tg3 led3 vc1 ovp3 ovp2 ovp1 tg1 led1 7 17 18 19 20 21 22 16 8 15 t jmax = 125c, ja = 43c/w, jc = 2.7c/w exposed pad (pin 29) is gnd, must be soldered to pcb order information lead free finish tape and reel part marking* package description temperature range ltc3496eufd#pbf ltc3496iufd#pbf ltc3496eufd#trpbf ltc3496iufd#trpbf 3496 3496 28-lead (4mm 5mm) plastic qfn 28-lead (4mm 5mm) plastic qfn 0c to 125c C40c to 125c consult ltc marketing for parts speci? ed with wider operating temperature ranges. *the temperature grade is identi? ed by a label on the shipping container. consult ltc marketing for information on non-standard lead based ? nish parts. *for more information on lead free part marking, go to: http://www.linear.com/leadfree/ for more information on tape and reel speci? cations, go to: http://www.linear.com/tapeandreel/
lt3496 3 3496f note 1: stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. exposure to any absolute maximum rating condition for extended periods may affect device reliability and lifetime. note 2: the lt3496e is guaranteed to meet performance speci? cations from 0c to 125c junction temperature. speci? cations over the C40c to 125c operating junction temperature range are assured by design, characterization and correlation with statistical process controls. the lt3496i is guaranteed and tested over the full C40c to 125c operating junction temperature range. electrical characteristics the denotes the speci? cations which apply over the full operating temperature range, otherwise speci? cations are at t a = 25c. v in = 5v, v ? s ? h ? d ? n = 5v, cap1-3 = 5v, pwm1-3 = 5v, fadj = 0.5v, ctrl1-3 = 1.5v, ovp1-3 = 0v, unless otherwise noted. parameter conditions min typ max units switching frequency fadj = 1.5v fadj = 0.5v fadj = 0.1v 1900 2100 1300 330 2300 khz khz khz maximum duty cycle fadj = 1.5v (2.1mhz) fadj = 0.5v (1.3mhz) fadj = 0.1v (330khz) 70 78 87 97 % % % ctrl1-3 input bias current current out of pin, ctrl1-3 = 0.1v 20 100 na fadj input bias current current out of pin, fadj = 0.1v 20 100 na ovp1-3 input bias current current out of pin, ovp1-3 = 0.1v 10 100 na ovp1-3 threshold 0.95 1 1.05 v vc1-3 idle input bias current pwm1-3 = 0v C20 0 20 na vc1-3 output impedance cap1-3 = 24v 4.5 m? eamp g m ( i vc / v cap-led ) cap1-3 = 24v 200 s sw1-3 current limit (note 3) 750 1000 1250 ma sw1-3 v cesat i sw = 500ma (note 3) 260 mv sw1-3 leakage current ? s ? h ? d ? n = 0v, sw = 5v 2 a cap1-3 input bias current 180 250 a cap1-3, led1-3 idle input bias current pwm1-3 = 0v 1 a cap1-3, led1-3 input bias current in shutdown ? s ? h ? d ? n = 0v 1 a ? s ? h ? d ? n input low voltage 0.3 v ? s ? h ? d ? n input high voltage 1.5 v ? s ? h ? d ? n pin current v ? s ? h ? d ? n = 5v 65 100 a pwm1-3 input low voltage 0.3 v pwm1-3 input high voltage 1.2 v pwm1-3 pin current 160 210 a gate off voltage (cap1-3Ctg1-3) cap1-3 = 40v, pwm1-3 = 0v 0.1 0.3 v gate on voltage (cap1-3Ctg1-3) cap1-3 = 40v 5.5 6.5 7.5 v gate turn-on delay c load = 300pf, cap1-3 = 40v (note 5) 110 ns gate turn-off delay c load = 300pf, cap1-3 = 40v (note 5) 110 ns note 3: current limit and switch v cesat is guaranteed by design and/or correlation to static test. note 4: absolute maximum voltage at the v in and ? s ? h ? d ? n pins is 40v for nonrepetitive 1 second transients, and 30v for continuous operation. note 5: gate turn-on/turn-off delay is measured from 50% level of pwm voltage to 90% level of gate on/off voltage.
lt3496 4 3496f quiescent current switch on voltage switch frequency vs fadj switch frequency vs temperature v cap-led threshold vs ctrl v cap-led threshold vs v cap switch current limit vs duty cycle v in (v) 0 8 10 14 30 3496 g01 6 4 10 20 40 2 0 12 input current (ma) pwm1-3 = 5v v c = gnd, not switching pwm1-3 = 0v switch current (ma) 0 switch voltage (mv) 300 400 500 800 3496 g02 200 100 0 200 400 600 1000 duty cycle (%) 0 switch current limit (ma) 600 800 1000 80 3496 g03 400 200 0 20 40 60 100 reference voltage vs temperature switch current limit vs temperature temperature ( c) ?0 current limit (ma) 800 1000 1200 25 75 3496 g04 600 400 ?5 0 50 100 125 200 0 ctrl (v) 0 0 v cap-led threshold (mv) 20 40 60 80 120 0.2 0.4 0.6 0.8 3496 g08 1 1.2 100 v cap = 24v v cap (v) 0 97 v cap-led trheshold (mv) 98 99 100 101 102 103 10 20 30 40 3496 g09 50 ctrl = 1.2v temperature ( c) ?0 v ref (v) 2.03 25 3496 g05 2.00 1.98 ?5 0 50 1.97 1.96 2.04 2.02 2.01 1.99 75 100 150 fadj (v) 0 0 switch frequency (khz) 250 750 1000 1250 0.8 2250 3496 g06 500 0.4 0.2 1.0 0.6 1.2 1500 1750 2000 temperature ( c) ?0 switch frequency (mhz) 2.1 2.2 2.3 2.4 25 75 3496 g07 2.0 1.9 ?5 0 50 100 125 1.8 fadj = 1.2v (t a = 25c unless otherwise noted) typical performance characteristics
lt3496 5 3496f v cap-led threshold vs temperature pmos turn on waveforms pmos turn off waveforms pin functions pwm1, pwm2, pwm3 (pins 1, 28, 27): pulse width modu- lated input. signal low turns off the respective converter, reduces quiescent supply current and causes the vc pin for that converter to become high impedance. pwm pin must not be left ? oating; tie to v ref if not used. v ref (pin 2): reference output pin. can supply up to 200a. the nominal output voltage is 2v. ctrl1, ctrl2, ctrl3 (pins 5, 4, 3): led current ad- justment pins. sets voltage across external sense resistor between cap and led pins of the respective converter. setting ctrl voltage to be less than 1v will control the current sense voltage to be one-tenth of ctrl voltage. if ctrl voltage is higher than 1v, the default current sense voltage is 100mv. the ctrl pin must not be left ? oating. fadj (pin 6): switching frequency adjustment pin. set- ting fadj voltage to be less than 1v will adjust switching frequency up to 2.1mhz. if fadj voltage is higher than 1v, the default switching frequency is 2.1mhz. the fadj pin must not be left ? oating. vc1, vc2, vc3 (pins 9, 8, 7): error ampli? er compensa- tion pins. connect a series rc from these pins to gnd. ovp1, ovp2, ovp3 (pins 12, 11, 10): open led protec- tion pins. a voltage higher than 1v on ovp turns off the internal main switch of the respective converter. tie to ground if not used. tg1, tg2, tg3 (pins 13, 17, 24): the gate driver output pin for disconnnect p-channel mosfet. one for each converter. when the pwm pin is low, the tg pin pulls up to cap to turn off the external mosfet. when the pwm pin is high, the external mosfet turns on. capn-tgn is limited to 7v to protect the mosfet. leave open if the external mosfet is not used. led1, led2, led3 (pins 14, 18, 23): noninverting input of current sense error ampli? er. connect directly to led current sense resistor terminal for current sensing of the respective converter cap1, cap2, cap3 (pins 15, 19, 22): inverting input of current sense error ampli? er. connect directly to other terminal of led current sense resistor terminal of the respective converter. sw1, sw2, sw3 (pins 16, 20 21): switch pins. collector of the internal npn power switch of the respective con- verter. connect to external inductor and anode of external schottky recti? er of the respective converter. minimize the metal trace area connected to this pin to minimize electromagnetic interference. v in (pin 25): input supply pin. must be locally bypassed. powers the internal control circuitry. temperature ( c) ?0 v cap-led threshold (mv) 101 102 103 25 75 3496 g10 100 99 ?5 0 50 100 125 98 97 ctrl = 1.2v v cap = 24v 5v 0v pwm 40v 30v tg 200ns/div v cap = 40v 3496 g11 200ns/div v cap = 40v 3496 g12 5v 0v pwm 40v 30v tg (t a = 25c unless otherwise noted) typical performance characteristics
lt3496 6 3496f + + + eamp a1 + v1 pwm1 vc 1v pwm comparator slope r1 2k + v sense i led led1 m1 r sense 0.2 ? a8 ctrl buffer q3 1v ctrl1 vc1 q1 gnd r2 20k r6 r5 + + a3 sr latch isens2 replicated for each channel shared components s rq a2 + a9 a6 npn driver + a10 29 a4 a7 mosfet driver a5 5 v in 25 v ref fadj 3496 bd 2 6 shdn 26 9 ovp1 r3 r4 r c 12 1 pwm1 13 tg1 14 led1 15 cap1 16 sw1 d1 l1 v in c2 c1 c c v in c3 c4 internal regulator and uvlo 2v reference ramp generator oscillator q2 v in isrc 200 a block diagram figure 1. lt3496 block diagram working in boost con? guration ? s ? h ? d ? n (pin 26): shutdown pin. used to shut down the switching regulator and the internal bias circuits for all three converters. tie to 1.5v or greater to enable the device. tie below 0.3v to turn off the device. exposed pad (pin 29): signal ground and power ground. solder paddle directly to ground plane. pin functions
lt3496 7 3496f applications information operation the lt3496 uses a ? xed frequency, current mode control scheme to provide excellent line and load regulation. op- eration can be best understood by referring to the block diagram in figure 1. the oscillator, ramp generator, refer- ence, internal regulator and uvlo are shared among the three converters. the control circuitry, power switch etc., are replicated for each of the three converters. figure 1 shows the shared circuits and only converter 1 circuits. if the ? s ? h ? d ? n pin is tied to ground, the lt3496 is shut down and draws minimal current from v in . if the ? s ? h ? d ? n pin exceeds 1.5v, the internal bias circuits turn on. the switching regulators start to operate when their respective pwm signal goes high. the main control loop can be understood by following the operation of converter 1. the start of each oscillator cycle sets the sr latch, a3, and turns on power switch q1. the signal at the noninverting input (slope node) of the pwm comparator a2 is proportional to the sum of the switch current and oscillator ramp. when slope exceeds vc (the output of the error ampli? er a1), a2 resets the latch and turns off the power switch q1 through a4 and a5. in this manner, a10 and a2 set the correct peak current level to keep the output in regulation. ampli? er a8 has two noninverting inputs, one from the 1v internal voltage reference and the other one from the ctrl1 pin. whichever input is lower takes precedence. a8, q3 and r1 force v1, the voltage across r1, to be one tenth of either 1v or the voltage of ctrl1 pin, whichever is lower. v sense is the voltage across the sensing resistor, r sense , which is connected in series with the leds. v sense is compared to v1 by a1. if v sense is higher than v1, the output of a1 will decrease, thus reducing the amount of current delivered to leds. in this manner the current sensing voltage v sense is regulated to v1. converter 2 and converter 3 operate identical to con- verter 1. pwm dimming control led1 can be dimmed with pulse width modulation us- ing the pwm1 pin and an external p-channel mosfet, m1. if the pwm1 pin is pulled high, m1 is turned on by internal driver a7 and converter 1 operates nominally. if the pwm1 pin is pulled low, q1 is turned off. converter 1 stops operating, m1 is turned off, disconnects led1 and stops current draw from output capacitor c2. the vc1 pin is also disconnected from the internal circuitry and draws minimal current from the compensation capacitor c c . the vc1 pin and the output capacitor store the state of the led1 current until pwm1 is pulled up again. this leads to a highly linear relationship between pulse width and output light, and allows for a large and accurate dim- ming range. to optimize the pwm control of all the three channels, the rising edge of all the three pwm signals should be synchronized. in the applications where high dimming ratio is not required, the external mosfet m1 can be omitted to reduce cost. in these conditions, tg1 should be left open. the pwm dimming range can be further increased by using ctrl1 pin to linearly adjust the current sense threshold during the pwm1 high state. open-led protection the lt3496 has open-led protection for all the three converters. as shown in figure 1, the ovp1 pin receives the output voltage (the voltage across the output capacitor) feedback signal from an external resistor divider. ovp1 voltage is compared with a 1v internal voltage reference by comparator a6. in the event the led string is disconnected or fails open, converter 1 output voltage will increase, caus- ing ovp1 voltage to increase. when ovp1 voltage exceeds 1v, the power switch q1 will turn off, and cause the output voltage to decrease. eventually, ovp1 will be regulated to 1v and the output voltage will be limited. in the event one of the converters has an open-led protection, the other converters will continue functioning properly.
lt3496 8 3496f switching frequency and soft-start the lt3496 switching frequency is controlled by fadj pin voltage. setting fadj voltage to be less than 1v will reduce switching frequency. if fadj voltage is higher than 1v, the default switch- ing frequency is 2.1mhz. in general, a lower switching frequency should be used where either very high or very low switch duty cycle is required or higher ef? ciency is desired. selection of a higher switching frequency will allow use of low value external components and yield a smaller solution size and pro? le. connecting fadj pin to a lowpass ? lter (r5 and c4 in figure 1) from the ref pin provides a soft-start function. during start-up, fadj voltage increases slowly from 0v to the setting voltage. as a result, the switching frequency increases slowly to the setting frequency. this function limits the inrush current during start-up. undervoltage lockout the lt3496 has an undervoltage lockout circuit that shuts down all the three converters when the input volt- age drops below 2.4v. this prevents the converter from switching in an erratic mode when powered from a low supply voltage. input capacitor selection for proper operation, it is necessary to place a bypass capacitor to gnd close to the v in pin of the lt3496. a 1f or greater capacitor with low esr should be used. a ceramic capacitor is usually the best choice. in the buck mode con? guration, the capacitor at pv in has large pulsed currents due to the current returned though the schottky diode when the switch is off. for the best reliability, this capacitor should have low esr and esl and have an adequate ripple current rating. the rms input current is: ii dd in rms led () = () 1 where d is the switch duty cycle. a 1f ceramic type ca- pacitor placed close to the schottky diode and the ground plane is usually suf? cient for each channel. output capacitor selection the selection of output ? lter capacitor depends on the load and converter con? guration, i.e., step-up or step-down. for led applications, the equivalent resistance of the led is typically low, and the output ? lter capacitor should be large enough to attenuate the current ripple. to achieve the same led ripple current, the required ? lter capacitor value is larger in the boost and buck-boost mode applications than that in the buck mode applications. for the led buck mode applications, a 0.22f ceramic capacitor is usually suf? cient for each channel. for the led boost and buck-boost applications, a 1f ceramic capacitor is usually suf? cient for each channel. use only ceramic capacitors with x7r or x5r dielectric, as they are good for temperature and dc bias stability of the capacitor value. all ceramic capacitors exhibit loss of capacitance value with increasing dc voltage bias, so it may be necessary to choose a higher value capacitor to get the required capacitance at the operation voltage. always check that the voltage rating of the capacitor is suf? cient. table 1 shows some recommended capacitor vendors. table 1. ceramic capacitor manufacturers vendor type series taiyo yuden ceramic x5r, x7r avx ceramic x5r, x7r murata ceramic x5r, x7r kemet ceramic x5r, x7r applications information
lt3496 9 3496f inductor selection several inductors that work well with the lt3496 are listed in table 2. however, there are many other manufacturers and devices that can be used. consult each manufacturer for more detailed information and their entire range of parts. ferrite core inductors should be used to obtain the best ef? ciency. choose an inductor that can handle the necessary peak current without saturating, and ensure that the inductor has a low dcr (copper-wire resistance) to minimize i 2 r power losses. an inductor with a magnetic shield should be used to prevent noise radiation and cross coupling among the three channels. table 2. surface mount inductors part number value (h) dcr ( max) i rms (a) size w l h (mm3) sumida cmd4d06 2.2 0.116 0.95 3.5 4.3 0.8 3.3 0.174 0.77 cdrh3d16 2.2 0.072 1.20 3.8 3.8 1.8 3.3 0.085 1.10 4.7 0.105 0.90 cdrh4d28 10 0.128 1.00 5.0 5.0 3.0 15 0.149 0.76 cdrh5d28 22 0.122 0.9 6.0 6.0 3.0 33 0.189 0.75 cooperet sd3112 2.2 0.140 0.97 3.1 3.1 1.2 3.3 0.165 0.90 4.7 0.246 0.74 sd14 10 0.2058 1.1 5.0 5.0 1.4 sd20 15 0.1655 1.25 5.0 5.0 2.0 22 0.2053 1.12 sd25 33 0.2149 1.11 5.0 5.0 2.5 tayio yuden nr3015 2.2 0.06 1.48 3.0 3.0 1.5 4.7 0.12 1.02 np04szb 4.7 0.075 1.6 4.0 4.0 1.8 10 0.100 1.2 15 0.180 0.95 22 0.210 0.77 diode selection the schottky diode conducts current during the interval when the switch is turned off. select a diode v r rated for the maximum sw voltage. it is not necessary that the forward current rating of the diode equal the switch current limit. the average current, i f , through the diode is a function of the switch duty cycle. select a diode with forward current rating of: i f = i l ? (1 C d) where i l is the inductor current. if using the pwm feature for dimming, it is important to consider diode leakage, which increases with the tem- perature from the output during the pwm low interval. therefore, choose the schottky diode with suf? cient low leakage current. table 3 shows several schottky diodes that work well with the lt3496. table 3. schottky diodes part number v r (v) i f (a) package zetex zlls350 40 0.38 sod523 zlls400 40 0.52 sod323 programming the led current the led current of each channel is programmed by con- necting an external sense resistor r sense in series with the led load, and setting the voltage regulation threshold across that sense resistor using ctrl input. if the ctrl voltage, v ctrl , is less than 1v, the led current is: i v r led ctrl sense = 10 if v ctrl is higher than 1v, the led current is: i mv r led sense = 100 applications information
lt3496 10 3496f applications information the ctrl pins should not be left open. the ctrl pin can also be used in conjunction with a ptc thermistor to provide overtemperature protection for the led load as shown in figure 2. board layout the high speed operation of the lt3496 demands careful attention to board layout and component placement. the exposed pad of the package is the only gnd terminal of the ic and is important for thermal management of the ic. therefore, it is crucial to achieve a good electrical and thermal contact between the exposed pad and the ground plane of the board. also, in boost con? guration, the schottky recti? er and the capacitor between gnd and the cathode of the schottky are in the high frequency switching path where current ? ow is discontinuous. these elements should be placed so as to minimize the path between sw and the gnd of the ic. to reduce electro- magnetic interference (emi), it is important to minimize the area of the sw node. use the gnd plane under sw to minimize interplane coupling to sensitive signals. to obtain good current regulation accuracy and eliminate sources of channel to channel coupling, the cap and led inputs of each channel of the lt3496 should be run as separate lines back to the terminals of the sense resistor. any resistance in series with cap and led inputs should be minimized. finally, the bypass capacitor on the v in supply to the lt3496 should be placed as close as possible to the v in terminal of the device. 50k 3496 f02 45k 2v v ref 5k ptc ctrl1-3 figure 2 thermal considerations the lt3496 is rated to a maximum input voltage of 30v for continuous operation, and 40v for nonrepetitive one second transients. careful attention must be paid to the internal power dissipation of the lt3496 at higher input voltages to ensure that a junction temperature of 125c is not exceeded. this is especially important when operat- ing at high ambient temperatures. the exposed pad on the bottom of the package must be soldered to a ground plane. this ground should then be connected to an internal copper ground plane with thermal vias placed directly under the package to spread out the heat dissipated by the lt3496.
lt3496 11 3496f typical applications minimum bom buck mode led driver 0.3a c4 0.22 f c5 0.22 f c6 0.22 f led1 330m ? 330m ? pv in 42v 7 leds l1 15 h l2 15 h l3 15 h cap1 0.3a led2 cap2 0.3a led3 c1-c3 1 f 3 330m ? 4.7k 22nf 3496 ta07a cap3 sw1 d1 d2 d3 open sw2 lt3496 gnd sw3 tg1-3 vc1-3 v ref ctrl1-3 fadj ovp1-3 cap1-3 led1-3 v in pwm1-3 shdn pwm1-3 shdn v in 3v c7 1 f c1-c3, c7: murata grm31mr71h105ka88 c4-c6: murata grm21br71h224ka01 d1-d3: diodes dfls160 l1-l3: taiyo yuden np04szb 150m 300:1 pwm dimming at 120hz ef? ciency pwm 5v/div i l 0.5a/div i led 0.5a/div 5 s/div 3496 ta07b i led (ma) 0 75 efficiency (%) 80 85 90 95 100 50 100 150 200 3496 ta07c 250 300 pwm = 3v ctrl = 0v to 1.2v
lt3496 12 3496f typical applications triple boost 100ma 10 led driver 10 leds c2 1 f c3 1 f c4 1 f pv in 12v 100ma 845k 20k ovp1 led1 tg1 1 ? 0.1 f 3496 ta03a l1 10 h l2 10 h l3 10 h cap1 d1 d2 d3 m1 m2 m3 sw1 sw2 lt3496 gnd sw3 tg1-3 ovp1-3 vc1-3 v ref fadj ctrl1-3 cap1-3 led1-3 v in pwm1-3 shdn pwm1-3 shdn v in 3v c1: murata grm31mr71c225ka35 c2-c5: murata grm31mr71h105ka88 d1-d3: diodes dfls160 l1-l3: taiyo yuden np04szb 100m m1-m3: zetex zxmp6a13f c5 1 f 10 leds 100ma 845k 20k ovp2 led2 tg2 1 ? cap2 10 leds 100ma 845k 20k ovp3 led3 tg3 1 ? cap3 c1 2.2 f ef? ciency vs i led i led (ma) 0 efficiency (%) 70 75 80 60 100 3496 ta03c 65 60 55 20 40 80 85 90 95 pwm = 3v ctrl = 0v to 1.2v pwm duty cycle (%) 0 50 efficiency (%) 55 65 70 75 40 80 100 95 3496 ta03d 60 20 60 80 85 90 ctrl = 2v 3000:1 pwm dimming at 120hz pwm 5v/div i l 0.5a/div i led 0.1a/div 0.5 s/div 3496 ta03b ef? ciency vs pwm duty cycle
lt3496 13 3496f typical applications dual boost led driver c2 1 f c3 1 f c4 1 f pv in 12v led1 m1 1 ? 0.1 f open 3496 ta04 l1 10 h l2 10 h l3 10 h cap1 d1 d2 d3 sw1 tg1 sw2 lt3496 gnd sw3 tg2 ovp1-3 tg3 vc1-3 v ref fadj ctrl1-3 cap1-3 led1-3 v in pwm1-3 shdn pwm shdn v in 3v to 12v c5 1 f c1 2.2 f led2 1 ? cap2 10 leds 200ma 20k ovp2-3 led3 m2 1 ? cap3 10 leds 100ma 845k 845k 20k ovp1 c1: murata grm31mr71c225ka35 c2-c5: murata grm31mr71h105ka88 d1-d3: diodes dfls160 l1-l3: taiyo yuden np04szb 100m m1, m2: zetex zxmp6a13f triple boost 20ma 8 led driver 8 leds c2 1 f c3 1 f c4 1 f pv in 5v 20ma 845k 20k ovp1 led1 tg1 5 ? 0.1 f 3496 ta08a l1 22 h l2 22 h l3 22 h cap1 d1 d2 d3 m1 m2 m3 sw1 sw2 lt3496 gnd sw3 tg1-3 ovp1-3 vc1-3 cap1-3 led1-3 v in pwm1-3 shdn pwm1-3 shdn v in 5v c1: murata grm31mr71c225ka35 c2-c5: murata grm31mr71h105ka88 d1-d3: zetex zlls350 l1-l3: taiyo yuden np04szb 220m m1-m3: zetex zxmp6a13f c5 1 f 8 leds 20ma 845k 20k ovp2 led2 tg2 5 ? cap2 8 leds 20ma 845k 82k ovp3 20k 20k led3 tg3 5 ? cap3 c1 2.2 f v ref ctrl1-3 fadj
lt3496 14 3496f typical applications buck-boost mode 300ma 6 led driver pv in 10v to 16v 0.1 f open 3496 ta05 sw1 sw2 pv in pv in lt3496 gnd sw3 tg1 ovp1-3 tg2-3 vc1-3 v ref fadj ctrl1-3 cap1-3 led1-3 v in pwm1-3 shdn pwm shdn v in 3v to 16v c8 1 f 6 leds 300ma 845k m1 d2 d3 20k ovp1-3 led3 1 ? l1 10 h l2 10 h l3 10 h cap3 led2 1 ? cap2 d1 c2 0.1 f c4 0.1 f c6 0.1 f c3 1 f led1 1 ? cap1 c1 2.2 f c5 1 f pv in c7 1 f c1: murata grm31mr71e225ka93 c2, c4, c6: murata grm21br71h104ka01b c3, c5, c7: murata grm31mr71h105ka88 c8: murata grm31mr71e105ka93 d1-d3: diodes dfls160 l1-l3: taiyo yuden np04szb 100m m1: zetex zxmp6a13f triple buck mode led driver with open led protection 0.5a c4 0.47 f c5 0.47 f c6 0.47 f d1 d2 d3 5.6k 5.6k 20k 20k 2k 2k led1 m1 m2 m3 200m ? 200m ? tg1 pv in 12v to 40v l1 10 h l2 10 h l3 10 h m4 ovp1 ovp2 m5 m6 cap1 0.5a led2 tg2 cap2 0.5a led3 c1-c3 1 f 3 200m ? 0.1 f 3496 ta02 tg3 cap3 sw1 sw2 lt3496 gnd sw3 tg1-3 ovp1-3 vc1-3 v ref fadj ctrl1-3 cap1-3 led1-3 v in pwm1-3 shdn pwm1-3 shdn v in 3v to 24v c7 1 f 5.6k 20k 2k ovp1 c1-c3, c7: murata grm31mr71h105ka88 c4-c6: murata grm188r71c474ka88 d1-d3: diodes dfls160 l1-l3: taiyo yuden np04szb 100m m1-m3: zetex zxmp6a13f m4-m6: philips bc858b
lt3496 15 3496f information furnished by linear technology corporation is believed to be accurate and reliable. however, no responsibility is assumed for its use. linear technology corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. package description ufd package 28-lead plastic qfn (4mm 5mm) (reference ltc dwg # 05-08-1712 rev b) 4.00 0.10 (2 sides) 2.50 ref 5.00 0.10 (2 sides) note: 1. drawing proposed to be made a jedec package outline mo-220 variation (wxxx-x). 2. drawing not to scale 3. all dimensions are in millimeters 4. dimensions of exposed pad on bottom of package do not include mold flash. mold flash, if present, shall not exceed 0.15mm on any side 5. exposed pad shall be solder plated 6. shaded area is only a reference for pin 1 location on the top and bottom of package pin 1 top mark (note 6) 0.40 0.10 27 28 1 2 bottom view?xposed pad 3.50 ref 0.75 0.05 r = 0.115 typ r = 0.05 typ pin 1 notch r = 0.20 or 0.35 45 chamfer 0.25 0.05 0.50 bsc 0.200 ref 0.00 ?0.05 (ufd28) qfn 0506 rev b recommended solder pad pitch and dimensions apply solder mask to areas that are not soldered 0.70 0.05 0.25 0.05 0.50 bsc 2.50 ref 3.50 ref 4.10 0.05 5.50 0.05 2.65 0.05 3.10 0.05 4.50 0.05 package outline 2.65 0.10 3.65 0.10 3.65 0.05
lt3496 16 3496f linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com ? linear technology corporation 2007 lt 0407 ? printed in usa related parts typical application part number description comments lt1618 constant current, 1.4mhz, 1.5a boost converter v in : 1.6v to 18v, v out(max) = 36v, i q = 1.8ma, i sd < 1a, 10-pin ms package lt3453 1mhz, 800ma synchronous buck-boost high power led driver v in : 2.7v to 5.5v, v out(max) = 5.5v, i q = 2.5ma, i sd < 6a, qfn package lt3466 dual constant current, 2mhz, high ef? ciency white led boost regulator with integrated schottky diode v in : 2.7v to 24v, v out(max) = 40v, i q = 5ma, i sd < 16a, dfn package lt3467/lt3467a 1.1a (isw), 1.3mhz/2.1mhz, high ef? ciency step-up dc/dc converters with integrated soft-start v in : 2.4v to 16v, v out(max) = 40v, i q = 1.2ma, i sd < 1a, thinsot tm package lt3474 step-down 1a 2mhz led driver v in : 4v to 36v, v out(max) = 15v, i q = 2.6ma, i sd < 1a, tssop package lt3475 dual step-down 1.5a, 2mv led driver v in : 4v to 36v, i q = 6ma, i sd < 1a, 20-lead tssope package lt3476 high current 2mhz quad 1.5a output led driver v in : 2.8v to 16v, v out(max) = 33.5v, i q = 5.5ma, i sd < 1a, 38-lead 5mm 7mm qfn package lt3477 3a, 42v, 3mhz step-up regulator with dual rail-to-rail current sense v in : 2.5v to 2.5v, v out(max) = 40v, i q = 5ma, i sd < 1a, qfn, 16-pin tssope packages lt3478/lt3478-1 4.5a, 2.25mhz led driver with 3000:1 ture color pwm tm dimming v in : 2.8v to 36v, v out(max) = 40v, i q = 6.1ma, i sd < 3a, 16-pin tssope package lt3479 3a, full-featured dc/dc converter with soft-start and inrush current protection v in : 2.5v to 24v, v out(max) = 40v, i q = 6.5ma, i sd < 1a, dfn, tssop packages thinsot and true color pwm are trademarks of linear technology corporation. triple buck-boost mode 100ma 6 led driver pv in 10v to 16v 0.1 f 3496 ta06 sw1 sw2 pv in lt3496 gnd sw3 tg1-3 ovp1-3 vc1-3 v ref fadj ctrl1-3 cap1-3 led1-3 v in pwm1-3 shdn pwm shdn v in 3v to 16v c8 1 f 6 leds 100ma 845k 20k ovp3 led3 tg3 1 l1 10 h l2 10 h l3 10 h cap3 led2 1 cap2 c2 0.1 f c4 0.1 f c6 0.1 f c5 1 f pv in c3 1 f pv in c7 1 f led1 d1 d2 d3 1 cap1 c1 2.2 f 6 leds 100ma 845k 20k ovp2 tg2 tg1 6 leds 100ma 845k m1 m2 m3 20k ovp1 c1: murata grm31mr71e225ka93 c2, c4, c6: murata grm21br71h104ka01b c3, c5, c7: murata grm31mr71h105ka88 c8: murata grm31mr71e105ka93 d1-d3: diodes dfls160 l1-l3: taiyo yuden np04szb 100m m1-m3: zetex zxmp6a13f pwm 5v/div i l 0.5a/div i led 0.1a/div 0.5 s/div 3496 ta06b 3000:1 pwm dimming at 120hz

▲Up To Search▲

Price & Availability of LTC3496EUFDTRPBF

	To Download LTC3496EUFDTRPBF Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .