View LT3484-1_1793713.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

lt3484-0/LT3484-1/lt3484-2 1 3484012f the lt 3484 family of photoflash capacitor charger ics is designed for use in digital camera and mobile phone applications where space is at a premium. the lt3484? patented control technique allows it to use extremely small transformers, and the improved npn power switch re- quires no external schottky diode clamp, reducing solu- tion size. output voltage detection requires no external circuitry as the transformer turns ratio determines final charge voltage. the devices feature a v bat pin, which allows the use of 2 alkaline cells to charge the capacitor. the lt3484-0, -2 and -1 have primary current limits of 1.4a, 1a and 0.7a respectively, resulting in tightly controlled average input current of 500ma, 350ma and 225ma respectively. the three versions are otherwise identical. the charge pin gives full control of the part to the user. driving charge low puts the part in shutdown. the done pin indicates when the part has completed charging. the lt3484 series of parts are housed in a tiny low profile 2mm 3mm dfn package. features descriptio u applicatio s u digital camera and cell phone flash charger highly integrated ic in 2mm 3mm dfn package reduces solution size uses small transformers: 5.8mm 5.8mm 3mm fast photoflash charge times: 4.6s for lt3484-0 (0v to 320v, 100 f, v in = 3.6v) 5.7s for lt3484-2 (0v to 320v, 100 f, v in = 3.6v) 5.5s for LT3484-1 (0v to 320v, 50 f, v in = 3.6v) operates from two aa batteries, or any supply from 1.8v up to 16v controlled average input current 500ma (lt3484-0) 350ma (lt3484-2) 225ma (LT3484-1) no output voltage divider needed no external schottky diode required charges any size photoflash capacitor available in 6-lead 2mm 3mm dfn package photoflash capacitor chargers danger high voltage ?operation by high voltage trained personnel only lt3484-0 photoflash charger uses high efficiency 3mm tall transformers lt3484-0 charge v in gnd v bat sw + done 4.7 f 100k 1:10.2 v bat 2aa or 1 to 2 li-ion 0.1 f v cc 5v 320v 1 2 4 5 348412 ta01 150 f photoflash capacitor lt3484-0 charging waveform typical applicatio u 3484 ta02 1s/div v out 50v/div average input current 1a/div v in = 3.6v c out = 100 f , ltc and lt are registered trademarks of linear technology corporation. all other trademarks are the property of their respective owners. protected by u.s. patents including 6636021.
lt3484-0/LT3484-1/lt3484-2 2 3484012f v in voltage .............................................................. 16v v bat voltage ............................................................ 16v sw voltage ................................................... 1v to 50v sw pin negative current ...................................... 0.5a charge voltage ...................................................... 10v done voltage .......................................................... 10v current into done pin .......................................... 1ma maximum junction temperature .......................... 125 c operating temperature range .................40 c to 85 c storage temperature range ..................65 c to 150 c absolute axi u rati gs w ww u package/order i for atio uu w (note 1) electrical characteristics the denotes the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. v in = v bat = v charge = 3v, unless otherwise noted. parameter conditions min typ max units quiescent current not switching 5 8 ma v charge = 0v 0 1 a v cc voltage range 2.5 16 v v bat voltage range 1.7 16 v switch current limit lt3484-0 1.1 1.2 1.3 a lt3484-2 0.75 0.85 0.95 a LT3484-1 0.45 0.55 0.65 a switch v cesat lt3484-0, i sw = 1a 330 430 mv lt3484-2, i sw = 650ma 210 280 mv LT3484-1, i sw = 400ma 150 200 mv v out comparator trip voltage measured as v sw ?v in 31 31.5 32 v v out comparator overdrive 300ns pulse width 200 400 mv dcm comparator trip voltage measured as v sw ?v in 10 60 120 mv charge pin current v charge = 3v 65 100 a v charge = 0v 0 0.1 a switch leakage current v in = v sw = 5v, in shutdown 0.01 1 a charge input voltage high 1v charge input voltage low 0.3 v done output signal high 100k ? from v in to done 3 v done output signal low 33 a into done pin 100 200 mv done leakage current v done = 3v, done npn off 20 100 na note 1: absolute maximum ratings are those values beyond which the life of a device may be impaired. t jmax = 125 c ja = 73.5 c/w exposed pad (pin 7) is gnd, must be soldered to pcb order part number dcb6 part marking consult ltc marketing for parts specified with wider operating temperature ranges. lt3484edcb-0 lt3484edcb-1 lt3484edcb-2 lbtm lbtn lbtp order options tape and reel: add #tr lead free: add #pbf lead free tape and reel: add #trpbf lead free part marking: http://www.linear.com/leadfree/ top view v bat sw sw done charge v in dcb6 package 6-lead (2mm 3mm) plastic dfn 4 5 7 6 3 2 1
lt3484-0/LT3484-1/lt3484-2 3 3484012f v in (v) 2 charge time (s) 3 4 56 3484 g04 7 10 9 8 7 6 5 4 3 2 1 0 charge time (s) 10 9 8 7 6 5 4 3 2 1 0 charge time (s) 10 9 8 7 6 5 4 3 2 1 0 8 v in (v) 23 4 5678 v in (v) 23 4 5678 3484 g05 3484 g06 50 f 100 f 50 f 100 f 20 f 50 f v in (v) v out (v) 327 326 325 324 323 322 321 320 3484 g07 23 456 78 v in (v) v out (v) 327 326 325 324 323 322 321 320 3484 g08 23 456 78 v in (v) v out (v) 327 326 325 324 323 322 321 3484 g09 23 456 78 t a = 40 c t a = 25 c t a = 85 c t a = 40 c t a = 25 c t a = 85 c t a = 40 c t a = 25 c t a = 85 c LT3484-1 charge time LT3484-1 charging waveform lt3484-0 charging waveform lt3484-0 charge time 3484 g01 3484 g02 typical perfor a ce characteristics uw 1s/div v out 50v/div 1s/div average input current 1a/div v out 50v/div average input current 0.5a/div lt3484-0 curves use the circuit of figure 6, LT3484-1 curves use the circuit of figure 7 and lt3484-2 use the circuit of figure 8, t a = 25 c unless otherwise noted. v in = 3.6v c out = 100 f v out 50v/div average input current 0.5a/div 1s/div 3484 g03 lt3484-2 charge time lt3484-2 charging waveform v in = 3.6v c out = 50 f v in = 3.6v c out = 100 f LT3484-1 output voltage lt3484-0 output voltage lt3484-2 output voltage
lt3484-0/LT3484-1/lt3484-2 4 3484012f v out (v) 50 efficiency (%) 100 150 200 250 3484 g16 300 90 85 80 75 70 65 60 55 50 45 40 v out (v) 50 efficiency (%) 100 150 200 250 3484 g17 300 90 85 80 75 70 65 60 55 50 45 40 v out (v) 50 efficiency (%) 100 150 200 250 3484 g18 300 90 85 80 75 70 65 60 55 50 45 40 v in = 2.4 v in = 3.6 v in = 4.2 v in = 2.4 v in = 3.6 v in = 4.2 v in = 2.4 v in = 3.6 v in = 4.2 temperature ( c) ?0 current limit (a) 0.70 0.66 0.62 0.58 0.54 0.50 0 40 60 3484 g11 ?0 20 80 100 temperature ( c) ?0 current limit (a) 1.5 1.4 1.3 1.2 1.1 0 40 60 3484 g10 ?0 20 80 100 temperature ( c) ?0 current limit (a) 1.00 0.96 0.92 0.88 0.84 0.80 0 40 60 3484 g12 ?0 20 80 100 v out (v) 800 600 400 200 0 3484 g13 0 50 250 300 100 150 200 current (ma) v out (v) 400 300 200 100 0 3484 g14 0 50 250 300 100 150 200 current (ma) v out (v) 600 450 300 150 0 3484 g15 0 50 250 300 100 150 200 current (ma) v in = 2.4 v in = 3.6 v in = 4.2 v in = 2.4 v in = 3.6 v in = 4.2 v in = 2.4 v in = 3.6 v in = 4.2 LT3484-1 switch current limit lt3484-0 switch current limit typical perfor a ce characteristics uw lt3484-0 curves use the circuit of figure 6, LT3484-1 curves use the circuit of figure 7 and lt3484-2 use the circuit of figure 8, t a = 25 c unless otherwise noted. lt3484-0 efficiency LT3484-1 efficiency lt3484-2 switch current limit lt3484-2 efficiency lt3484-0 input current LT3484-1 input current lt3484-2 input current
lt3484-0/LT3484-1/lt3484-2 5 3484012f v in = 3.6v v out = 300v 3484 g24 1 s/div v sw 10v/div i pri 1a/div v in = 3.6v v out = 100v 3484 g21 1 s/div v sw 10v/div i pri 1a/div lt3484-0 switching waveform lt3484-0/LT3484-1/lt3484-2 switch breakdown voltage LT3484-1 switching waveform v in = 3.6v v out = 100v 3484 g19 1 s/div v sw 10v/div i pri 1a/div v in = 3.6v v out = 300v 3484 g23 1 s/div v sw 10v/div i pri 1a/div lt3484-0 curves use the circuit of figure 6, LT3484-1 curves use the circuit of figure 7 and lt3484-2 use the circuit of figure 8, t a = 25 c unless otherwise noted. typical perfor a ce characteristics uw switch voltage (v) 0 102030405060708090100 switch current (ma) 3484 g25 10 9 8 7 6 5 4 3 2 1 0 t = ?0 c t = 25 c t = 85 c sw pin is resistive until breakdown voltage due to integrated resistors. this does not increase quiescent current of part v in = v charge = 5v lt3484-0 switching waveform 3484 g20 1 s/div v sw 10v/div i pri 1a/div v in = 3.6v v out = 300v LT3484-1 switching waveform v in = 3.6v v out = 100v 3484 g22 1 s/div v sw 10v/div i pri 1a/div lt3484-2 switching waveform lt3484-2 switching waveform
lt3484-0/LT3484-1/lt3484-2 6 3484012f done (pin 1): open npn collector indication pin. when target output voltage is reached, npn turns on, pulling pin 1 low. this pin needs a pull-up resistor or current source. charge (pin 2): charge pin. a low (<0.3v) to high (>1v) transition on this pin puts the part into power delivery mode. once the target voltage is reached, the part will stop charging the output. toggle this pin to start charging again. bringing the pin low (<0.3v) will terminate the power delivery and put the part in shutdown. v in (pin 3): input supply pin. must be locally bypassed with a good quality ceramic capacitor. input supply must be 2.5v or higher. sw (pins 4, 5): switch pins. these are the collector of the internal npn power switch. tie these pins together on the pc board. minimize the metal trace area connected to these pins to minimize emi. tie one side of the primary of the transformer to these pins. the target output voltage is set by the turns ratio of the transformer. choose turns ratio n by the following equation: n v out = + 2 31 5 . where v out is the desired output voltage. v bat (pin 6): battery supply pin. must be locally bypassed with a good quality ceramic capacitor. battery supply must be 1.7v or higher. the other terminal of the transformer primary must be connected to v bat . gnd (pin 7): ground. tie directly to local ground plane. uu u pi fu ctio s v bat sw + done charge c1 t1 r2 60k q1 enable chip power c out photoflash capacitor 40mv 20mv to battery q2 v out d1 lt3484-0: r sense = 0.015 ? lt3484-2: r sense = 0.022 ? LT3484-1: r sense = 0.03 ? 3484 bd 4, 5 gnd 6 1 2 7 + + + + + one- shot one- shot driver primary secondary master latch r sense dcm comparator v out comparator r1 2.5k s rq 1.25v reference q3 q1 qq sr a3 a1 a2 v in to v cc 3 figure 1 fu ctio al block diagra uu w
lt3484-0/LT3484-1/lt3484-2 7 3484012f the charge pin gives full control of the part to the user. the charging can be halted at any time by bringing the charge pin low. only when the final output voltage is reached will the done pin go low. figure 2 shows these various modes in action. when charge is first brought high, charging commences. when charge is brought low during charging, the part goes into shutdown and v out no longer rises. when charge is brought high again, charging resumes. when the target v out voltage is reached, the done pin goes low and charging stops. finally the charge pin is brought low again so the part enters shutdown and the done pin goes high. both v bat and v in have undervoltage lockout (uvlo). when one of these pins goes below its uvlo voltage, the done pin goes low. with an insufficient bypass capacitor on v bat or v in , the ripple on the pin is likely to activate the uvlo and terminate the charge. the application diagrams suggest values adequate for most applications. operatio u the lt3484-0/LT3484-1/lt3484-2 are designed to charge photoflash capacitors quickly and efficiently. the opera- tion of the part can be best understood by referring to figure 1. when the charge pin is first driven high, a one shot sets both sr latches in the correct state. the power npn device, q1, turns on and current begins ramping up in the primary of transformer t1. comparator a1 monitors the switch current and when the peak current reaches 1.4a (lt3484-0), 1a(lt3484-2) or 0.7a (LT3484-1), q1 is turned off. since t1 is utilized as a flyback transformer, the flyback pulse on the sw pin will cause the output of a3 to be high. the voltage on the sw pin needs to be at least 40mv higher than v bat for this to happen. during this phase, current is delivered to the photoflash capacitor via the secondary and diode d1. as the second- ary current decreases to zero, the sw pin voltage will begin to collapse. when the sw pin voltage drops to 40mv above v bat or lower, the output of a3 (dcm comparator) will go low. this fires a one shot which turns q1 back on. this cycle will continue to deliver power to the output. output voltage detection is accomplished via r2, r1, q2, and comparator a2 (v out comparator). resistors r1 and r2 are sized so that when the sw voltage is 31.5v above v in , the output of a2 goes high which resets the master latch. this disables q1 and halts power delivery. npn transistor q3 is turned on pulling the done pin low, indicating that the part has finished charging. power delivery can only be restarted by toggling the charge pin. lt3484-2 v in = 3.6v c out = 50 f v out 100v/div v charge 5v/div v done 5v/div 1s/div 3484 f02 figure 2. halting the charging cycle with the charge pin applicatio s i for atio wu u u choosing the right device (lt3484-0/LT3484-1/lt3484-2) the only difference between the three versions of the lt3484 is the peak current level. for the fastest possible charge time, use the lt3484-0. the LT3484-1 has the lowest peak current capability, and is designed for appli- cations that need a more limited drain on the batteries. due to the lower peak current, the LT3484-1 can use a physi- cally smaller transformer. the lt3484-2 has a current limit in between that of the lt3484-0 and the LT3484-1. transformer design the flyback transformer is a key element for any lt3484-0/LT3484-1/lt3484-2 design. it must be de- signed carefully and checked that it does not cause exces- sive current or voltage on any pin of the part. the main parameters that need to be designed are shown in table 1. the first transformer parameter that needs to be set is the turns ratio n. the lt3484-0/LT3484-1/lt3484-2 accom- plish output voltage detection by monitoring the flyback waveform on the sw pin. when the sw voltage reaches 31.5v higher than the v bat voltage, the part will halt power delivery. thus, the choice of n sets the target output
lt3484-0/LT3484-1/lt3484-2 8 3484012f voltage as it changes the amplitude of the reflected voltage from the output to the sw pin. choose n according to the following equation: n v out = + 2 31 5 . where: v out is the desired output voltage. the number 2 in the numerator is used to include the effect of the voltage drop across the output diode(s). thus for a 320v output, n should be 322/31.5 or 10.2. for a 300v output, choose n equal to 302/31.5 or 9.6. the next parameter that needs to be set is the primary inductance, l pri . choose l pri according to the following formula: l v ni pri out pk ? 200 10 9 where: v out is the desired output voltage. n is the transformer turns ratio. i pk is 1.4 (lt3484-0), 0.7 (LT3484-1), and 1.0 (lt3484-2). l pri needs to be equal or larger than this value to ensure that the lt3484-0/LT3484-1/lt3484-2 has adequate time to respond to the flyback waveform. all other parameters need to meet or exceed the recom- mended limits as shown in table 1. a particularly impor- tant parameter is the leakage inductance, l leak . when the power switch of the lt3484-0/LT3484-1/lt3484-2 turns off, the leakage inductance on the primary of the trans- former causes a voltage spike to occur on the sw pin. the height of this spike must not exceed 40v , even though the absolute maximum rating of the sw pin is 50v. the 50v absolute maximum rating is a dc blocking voltage speci- fication, which assumes that the current in the power npn is zero. figure 3 shows the sw voltage waveform for the circuit of figure 6 (lt3484-0). note that the absolute maximum rating of the sw pin is not exceeded. make sure to check the sw voltage waveform with v out near the target output voltage, as this is the worst case condition for sw voltage. figure 4 shows the various limits on the sw voltage during switch turn off. it is important not to minimize the leakage inductance to a very low level. although this would result in a very low leakage spike on the sw pin, the parasitic capacitance of the transformer would become large. this will adversely affect the charge time of the photoflash circuit. linear technology has worked with several leading mag- netic component manufacturers to produce pre-designed flyback transformers for use with the lt3484-0/ LT3484-1/lt3484-2. table 2 shows the details of several of these transformers. applicatio s i for atio wu u u table 1. recommended transformer parameters typical range typical range typical range parameter name lt3484-0 LT3484-1 lt3484-2 units l pri primary inductance >5 >10 >7 h l leak primary leakage inductance 100 to 300 200 to 500 200 to 500 nh n secondary: primary turns ratio 1:8 to 1:12 1:8 to 1:12 1:8 to 1:12 v iso secondary to primary isolation voltage >500 >500 >500 v i sat primary saturation current >1.6 >0.8 >1.0 a r pri primary winding resistance <300 <500 <400 m ? r sec secondary winding resistance <40 <80 <60 ?
lt3484-0/LT3484-1/lt3484-2 9 3484012f table 2. pre-designed transformers ?typical specifications unless otherwise noted size l pri lpri-leakage r pri r sec for use with transformer name (w l h) mm ( h) (nh) n (m ? )( ? ) vendor lt3484-0/lt3484-2 sbl-5.6-1 5.6 8.5 4.0 10 200 max 10.2 103 26 kijima musen LT3484-1 sbl-5.6s-1 5.6 8.5 3.0 24 400 max 10.2 305 55 hong kong office 852-2489-8266 (ph) kijimahk@netvigator.com (email) lt3484-0 ldt565630t-001 5.8 5.8 3.0 6 200 max 10.4 100 max 10 max tdk LT3484-1 ldt565630t-002 5.8 5.8 3.0 14.5 500 max 10.2 240 max 16.5 max chicago sales office lt3484-2 ldt565630t-003 5.8 5.8 3.0 10.5 550 max 10.2 210 max 14 max (847) 803-6100 (ph) www.components.tdk.com lt3484-0/lt3484-2 t-15-089 6.4 7.7 4.0 12 400 max 10.2 211 max 27 max tokyo coil engineering LT3484-1 t-15-083 8.0 8.9 2.0 20 500 max 10.2 675 max 35 max japan office 0426-56-6262 (ph) www.tokyo-coil.co.jp capacitor selection for the input bypass capacitors, high quality x5r or x7r types should be used. make sure the voltage capability of the part is adequate. output diode selection the rectifying diode(s) should be low capacitance type with sufficient reverse voltage and forward current rat- ings. the peak reverse voltage that the diode(s) will see is approximately: vvnv pk r out in ? =+ () the peak current of the diode is simply: i n pk sec ? = 14 . (lt3484-0) i n pk sec ? = 10 . (lt3484-2) i n pk sec ? = 07 . (LT3484-1) for the circuit of figure 6 with v bat of 5v, v pk-r is 371v and i pk-sec is 137ma. the gsd2004s dual silicon diode is recommended for most lt3484-0/LT3484-1/lt3484-2 applications. another option is to use the bav23s dual silicon diodes. table 3 shows the various diodes and relevant specifications. use the appropriate number of diodes to achieve the necessary reverse breakdown voltage. applicatio s i for atio wu u u figure 4. new transformer design check (not to scale) figure 3. lt3484-0 sw voltage waveform 3484 f03 100ns/div v sw 10v/div v sw 3484 f04 0v ? ? must be less than 40v must be less than 50v v in = 5v v out = 320v
lt3484-0/LT3484-1/lt3484-2 10 3484012f board layout the high voltage operation of the lt3484-0/LT3484-1/ lt3484-2 demands careful attention to board layout. you will not get advertised performance with careless layout. figure 5 shows the recommended component placement. keep the area for the high voltage end of the secondary as small as possible. also note the larger than minimum spacing for all high voltage nodes in order to meet break- down voltage requirements for the circuit board. it is imperative to keep the electrical path formed by c1, the primary of t1, and the lt3484-0/LT3484-1/lt3484-2 as short as possible. if this path is haphazardly made long, it will effectively increase the leakage inductance of t1, which may result in an overvoltage condition on the sw pin. applicatio s i for atio wu u u figure 5. suggested layout: keep electrical path formed by c1, transformer primary and lt3484-0/LT3484-1/lt3484-2 short r1 d1 (dual diode) c1 secondary primary c out photoflash capacitor t1 v in v bat charge done c2 + 3484 f05 4 5 6 3 2 1 typical applicatio s u r1 100k c2 0.1 f v in 2.5v to 8v + done charge c1 4.7 f t1 1:10.2 v bat 1.8v to 8v 320v 1 2 4 5 3484 f06 c out photoflash capacitor c1: 4.7 f, x5r or x7r, 10v t1: kijima musen part# sbl-5.6-1, l pri = 10 h, n = 10.2 d1: vishay gsd2004s dual diode connected in series r1: pull up resistor needed if done pin used d1 2 3 1 7 6 4, 5 charge v in done lt3484-0 gnd v bat sw r1 100k c2 0.1 f v in 2.5v to 8v done charge v bat 1.8v to 8v c1: 4.7 f, x5r or x7r, 10v t1: kijima musen part# sbl-5.6s-1, l pri = 24 h, n = 10.2 d1: vishay gsd2004s dual diode connected in series r1: pull up resistor needed if done pin used + c1 4.7 f t1 1:10.2 c out photoflash capacitor 320v d1 4 3 5 6 3484 f07 2 3 1 7 6 4, 5 charge v in done LT3484-1 v bat gnd sw figure 6. lt3484-0 photoflash charger uses high efficiency 4mm tall transformer figure 7. LT3484-1 photoflash charger uses high efficiency 3mm tall transformer table 3. recommended output diodes max reverse voltage max forward continuous current capacitance part (v) (ma) (pf) vendor gsd2004s 2x300 225 5 vishay (dual diode) (402) 563-6866 www.vishay.com bav23s 2x250 225 5 philips semiconductor (dual diode) (800) 447-1500 www.philips.com mmbd3004s 2x350 225 5 diodes inc (dual diode) (816) 251-8800 www.diodes.com
lt3484-0/LT3484-1/lt3484-2 11 3484012f u package descriptio 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. typical applicatio s u r1 100k c2 0.1 f v cc 2.5v to 8v done charge v bat 1.8v to 8v c1: 4.7 f, x5r or x7r, 10v t1: tdk ldt565630t-003 l pri = 10.5 h, n = 10.2 d1: vishay gsd2004s dual diode connected in series r1: pull up resistor needed if done pin used + c1 4.7 f t1 1:10.2 c out photoflash capacitor 320v d1 5 8 4 1 3484 f08 2 3 1 7 6 4, 5 charge v in done lt3484-2 v bat gnd sw figure 8. lt3484-2 photoflash charger uses high efficiency 3mm tall transformer dcb package 6-lead plastic dfn (2mm 3mm) (reference ltc dwg # 05-08-1715) 3.00 0.10 (2 sides) 2.00 0.10 (2 sides) note: 1. drawing to be made a jedec package outline m0-229 variation of (tbd) 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 0.40 0.10 bottom view?xposed pad 1.65 0.10 (2 sides) 0.75 0.05 r = 0.115 typ r = 0.05 typ 1.35 0.10 (2 sides) 1 3 6 4 pin 1 bar top mark (see note 6) 0.200 ref 0.00 ?0.05 (dcb6) dfn 0405 0.25 0.05 0.50 bsc pin 1 notch r0.20 or 0.25 45 chamfer 0.25 0.05 1.35 0.05 (2 sides) recommended solder pad pitch and dimensions 1.65 0.05 (2 sides) 2.15 0.05 0.70 0.05 3.55 0.05 package outline 0.50 bsc
lt3484-0/LT3484-1/lt3484-2 12 3484012f linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com ? linear technology corporation 2005 lt/tp 0705 500 ? printed in usa related parts part number description comments ltc3407 dual 600ma (i out ), 1.5mhz, synchronous step-down dc/dc 96% efficiency, v in : 2.5v to 5.5v, v out(min) = 0.6v, i q = 40 a, converter i sd <1 a, ms10e package lt3420/lt3420-1 1.4a/1a, photoflash capacitor chargers with charges 220 f to 320v in 3.7 seconds from 5v, automatic top-off v in : 2.2v to 16v, i q = 90 a, i sd <1 a, ms10 package ltc3425 5a i sw , 8mhz, multi-phase synchronous step-up dc/dc 95% efficiency, v in : 0.5v to 4.5v, v out(min) = 5.25v, i q = 12 a, converter i sd <1 a, qfn-32 package ltc3440 600ma (i out ), 2mhz, synchronous buck-boost dc/dc 95% efficiency, v in : 2.5v to 5.5v, v out(min) : 2.5v to 5.5v, converter i q = 25 a, i sd <1 a, ms-10 package lt3468/lt3468-1/ 1.4a/0.7a/1a photoflash capacitor chargers in thinsot charges 100 f to 320v in 4.6 seconds from 5v, v in : 2.5v to 16v, lt3468-2 i q = 5ma, i sd <1 a, thinsot package typical applicatio s u lt3484-0 photoflash circuit uses tiny 3mm tall transformer LT3484-1 photoflash circuit uses tiny 3mm tall transformer r1 100k c2 0.1 f v cc 2.5v to 8v done charge v bat 1.8v to 8v c1: 4.7 f, x5r or x7r, 10v t1: tdk part# ldt565630t-001, l pri = 6 h, n = 10.4 d1: vishay gsd2004s dual diode connected in series r1: pull up resistor needed if done pin used + c1 4.7 f t1 1:10.4 c out photoflash capacitor 320v d1 5, 6 7, 8 4 1 3484 ta03 2 3 1 7 6 4, 5 charge v in done v bat lt3484-0 gnd sw r1 100k c2 0.1 f v cc 2.5v to 8v done charge v bat 1.8v to 8v c1: 4.7 f, x5r or x7r, 10v t1: tdk part# ldt565630t-002, l pri = 14.5 h, n = 10.2 d1: vishay gsd2004s dual diode connected in series r1: pull up resistor needed if done pin used + c1 4.7 f t1 1:10.2 c out photoflash capacitor 320v d1 5 8 4 1 3484 ta04 2 3 1 7 6 4, 5 charge v in done v bat LT3484-1 gnd sw charge time charge time v in (v) 2345678 charge time (s) 3484 ta05 8 7 6 5 4 3 2 1 0 c out = 50 f c out = 100 f v in (v) 2345678 charge time (s) 3484 ta06 8 7 6 5 4 3 2 1 0 c out = 50 f c out = 20 f thinsot is a trademark of linear technology corporation.

▲Up To Search▲

Price & Availability of LT3484-1

	To Download LT3484-1 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .