View LTC3539_2475386.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

LTC3539/LTC3539-2 1 3539f typical application features applications description 2a, 1mhz/2mhz synchronous step-up dc/dc converters the ltc ? 3539/LTC3539-2 are synchronous, 2a step-up dc/dc converters with output disconnect. synchronous recti? cation enables high ef? ciency in the low pro? le 2mm 3mm dfn package. battery life is extended with a 700mv start-up voltage and operation down to 500mv once started. a switching frequency of 1mhz (LTC3539) or 2mhz (LTC3539-2) minimizes solution footprint by allowing the use of tiny, low pro? le inductors and ceramic capacitors. the current mode pwm design is internally compensated, reducing external parts count. the LTC3539/LTC3539-2 feature a pin-enabled automatic burst mode operation at light load conditions. anti-ring circuitry reduces emi by damping the inductor in discontinuous mode. additional features include a low shutdown current of under 1a and thermal overload protection. the LTC3539/LTC3539-2 are offered in a 2mm 3mm 0.75mm dfn package. wide v in , high power 3.3v regulator n delivers 3.3v at 900ma from 2 alkaline/nimh cells n delivers 5v at 900ma from a lithium-polymer battery n v in start-up voltage: 700mv n 1.5v to 5.25v v out range n up to 94% ef? ciency n v in > v out operation n 1mhz (LTC3539) or 2mhz (LTC3539-2) fixed frequency operation n output disconnect n selectable burst mode ? or pwm operation n 10a quiescent current n logic controlled shutdown: <1a n requires only 6 external components n low pro? le (2mm 3mm 0.75mm) dfn package n medical instruments n portable bar code scanners n noise canceling headphones n portable gps navigation n handheld pcs l , lt, ltc, ltm and burst mode are registered trademarks of linear technology corporation. all other trademarks are the property of their respective owners. i load average (ma) 0.1 1 10 100 1000 0.1 1 10 100 1000 efficiency (%) power loss (mw) 100 80 60 40 20 0 90 70 50 30 10 3539 ta01b power loss efficiency v in = 2.4v v out = 3.3v frequency = 1mhz frequency = 2mhz ef? ciency and power loss vs load current 3539 ta01a LTC3539 v in sw 2.2f v out 3.3v 600ma v in 1.8v to 3.6v 4.7h v out mode shdn fb pgnd gnd 562k 1m 22f 22pf burst pwm on off
LTC3539/LTC3539-2 2 3539f pin configuration absolute maximum ratings v in voltage ................................................... C0.3v to 6v sw voltage dc ............................................................ C0.3v to 6v pulsed <100ns ......................................... C0.3v to 7v shdn , fb, mode voltage ............................ C0.3v to 6v v out ............................................................. C0.3v to 6v operating temperature (notes 2, 5) ......... C40c to 85c storage temperature range ................... C65c to 125c (note 1) top view v out mode fb shdn sw pgnd gnd v in dcb package 8-lead (2mm s 3mm) plastic dfn 9 3 4 2 1 6 5 7 8 t jmax = 125c, ja = 60c/w to 85c/w (note 6) exposed pad (pin 9) is gnd, must be soldered to pcb order information electrical characteristics parameter conditions min typ max units input voltage range after start-up 0.5 5 v minimum start-up voltage i load = 1ma, v out = 0v 0.7 0.88 v output voltage adjust range l 1.5 5.25 v feedback voltage l 1.170 1.200 1.230 v feedback input current v fb = 1.2v 1 50 na quiescent current - shutdown v shdn = 0v, not including switch leakage, v out = 0v 0.01 1 a quiescent current - active measured on v out , non-switching 300 500 a quiescent current - burst measured on v out , fb >1.230v 10 18 a n-channel mosfet switch leakage current v sw = 5v 0.1 10 a p-channel mosfet switch leakage current v sw = 5v, v out = 0v 0.1 20 a n-channel mosfet switch on resistance v out = 3.3v 0.09 p-channel mosfet switch on resistance v out = 3.3v 0.125 n-channel mosfet current limit l 2 2.6 a the l denotes the speci? cations which apply over the speci? ed temperature range of C40c to 85c, otherwise speci? cations are at t a = 25c. v in = 1.2v, v out = 3.3v, unless otherwise noted. lead free finish tape and reel part marking package description temperature range LTC3539edcb#pbf LTC3539edcb#trpbf ldcs 8-lead (2mm 3mm) plastic dfn C40c to 85c LTC3539edcb-2#pbf LTC3539edcb-2#trpbf ldph 8-lead (2mm 3mm) plastic dfn C40c to 85c consult ltc marketing for parts speci? ed with wider operating temperature ranges. 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/
LTC3539/LTC3539-2 3 3539f electrical characteristics 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 LTC3539e/LTC3539e-2 is guaranteed to meet performance speci? cations from 0c to 85c. speci? cations over C40c to 85c operating temperature range are assured by design, characterization and correlation with statistical process controls. note 3: speci? cation is guaranteed by design and not 100% tested in production. parameter conditions min typ max units maximum duty cycle v fb = 1.15v l 87 90 % minimum duty cycle v fb = 1.3v l 0% switching frequency LTC3539 LTC3539-2 l l 0.7 1.8 1 2 1.3 2.4 mhz mhz mode input high voltage 0.88 v mode input low voltage 0.3 v mode input current v mode = 1.2v 0.3 1 a shdn input high voltage 0.88 v shdn input low voltage 0.3 v shdn input current v shdn = 1.2v v shdn = 3.3v 0.3 1 1 2 a a the l denotes the speci? cations which apply over the speci? ed temperature range of C40c to 85c, otherwise speci? cations are at t a = 25c. v in = 1.2v, v out = 3.3v, unless otherwise noted. note 4: current measurements are made when the output is not switching. note 5: this ic includes overtemperature protection that is intended to protect the device during momentary overload conditions. junction temperature will exceed 125c when overtemperature protection is active. continuous operation above the speci? ed maximum operating junction temperature may result in device degradation or failure. note 6: failure to solder the exposed backside of the package to the pc board ground plane will result in a thermal resistance much higher than 60c/w.
LTC3539/LTC3539-2 4 3539f v in (v) i out (ma) 2000 200 1800 1400 1000 600 1600 1200 800 400 0 3539 g05 v out = 1.8v v out = 2.5v v out = 3.3v v out = 5v 0.5 1.5 2.5 1.0 2.0 3.5 5.0 4.5 3.0 4.0 v in (v) i in (a) 100 10 90 70 50 30 80 60 40 20 0 3539 g04 v out = 1.8v v out = 2.5v v out = 3.3v v out = 5v 0.5 1.5 2.5 1.0 2.0 3.5 4.5 3.0 4.0 typical performance characteristics ef? ciency vs load current and v in , v out = 1.8v ef? ciency vs load current and v in , v out = 3.3v ef? ciency vs load current and v in , v out = 5v no load input current vs v in maximum output current vs v in load current (ma) efficiency (%) 100 10 90 70 50 30 80 60 40 20 0 power loss (mw) 1000 100 10 1 0.1 0.01 3539 g01 v in = 1v v in = 1.2v v in = 1.5v power loss efficiency 0.1 100 1000 10 1 load current (ma) efficiency (%) 100 10 90 70 50 30 80 60 40 20 0 3539 g02 v in = 1.2v v in = 1.8v v in = 3v power loss efficiency 0.1 100 1000 10 1 0.1 1 10 100 1000 power loss (mw) 0.1 1 10 100 1000 power loss (mw) load current (ma) efficiency (%) 100 10 90 70 50 30 80 60 40 20 0 3539 g03 v in = 2.4v v in = 3.6v v in = 4.2v power loss efficiency 0.1 100 1000 10 1 minimum load resistance during start-up vs v in burst mode threshold current vs v in and v out 0.65 0.85 1.05 0.75 0.95 1.15 v in (v) load resistance () 3539 g06 10000 1000 100 10 0.1 v out = 3.3v input voltage (v) output current (ma) 60 50 30 10 40 20 0 3539 g11 v out = 1.8v v out = 2.5v v out = 3.3v v out = 5v 0.5 0 1.5 2.5 1.0 2.0 3.5 4.5 3.0 4.0 (t a = 25c unless otherwise noted) normalized current limit vs v out v out (v) normalized current limit (a) 1.10 1.05 0.95 0.85 1.00 0.90 0.80 3539 g16 1.0 1.5 2.5 2.0 3.5 5.0 4.5 3.0 4.0
LTC3539/LTC3539-2 5 3539f temperature (c) v in (v) 0.80 0.75 0.65 0.55 0.70 0.60 0.50 3539 g10 1ma load no load C50 0 C25 50 100 25 75 temperature (c) change in v fb (%) 0.50 0.25 C0.25 C0.75 0 C0.50 C1.00 3539 g09 C60 C20 C40 40 100 80 20 060 v out (v) r ds(on) () 0.30 0.25 0.15 0.05 0.20 0.10 0 3539 g07 nmos pmos 1.5 2.5 2.0 3.5 5.5 5.0 4.5 3.0 4.0 temperature (c) normalized r ds(on) () 1.3 1.2 1.0 0.8 1.1 0.9 0.7 3539 g08 C50 C10 C30 30 90 70 10 50 typical performance characteristics r ds(on) vs v out r ds(on) change vs temperature v fb vs temperature start-up voltage vs temperature fixed frequency sw and i l(ac) burst mode sw and i l(ac) load step, fixed frequency load step, burst mode operation 500ns/div v in = 2.4v v out = 3.3v at 400ma c out = 22f v out 20mv/div ac-coupled inductor current 500ma/div sw pin 2v/div 3539 g12 500s/div v in = 2.4v v out = 3.3v c out = 22f i load = 100ma to 250ma step v out 50mv/div ac-coupled load current 200ma/div 3539 g14 5s/div v in = 3.3v v out = 5v c out = 22f v out 20mv/div ac-coupled inductor current 200ma/div sw pin 5v/div 3539 g13 500s/div v in = 2.4v v out = 3.3v c out = 22f i load = 20ma to 170ma v out 50mv/div ac-coupled load current 200ma/div 3539 g15
LTC3539/LTC3539-2 6 3539f block diagram pin functions sw (pin 1): switch pin. connect inductor between sw and v in . keep pcb trace lengths as short and wide as pos- sible to reduce emi. if the inductor current falls to zero, or shdn is low, an internal anti-ring resistor is connected from sw to v in to minimize emi. pgnd (pin 2), gnd (pin 3): signal and power ground. provide a short direct pcb path between pgnd, gnd and the (C) side of the input and output capacitors. v in (pin 4): battery input voltage. connect a minimum of 2.2f ceramic decoupling capacitor from this pin to ground. shdn (pin 5): logic controlled shutdown input. there is an internal 4m pull-down on this pin. shdn = high: normal operation. shdn = low: shutdown, quiescent current <1a. fb (pin 6): feedback input to the g m error ampli? er. con- nect resistor divider tap to this pin. the output voltage can be adjusted from 1.5v to 5.25v by: v out = 1.20v ? [1 + (r2/r1)] mode (pin 7): burst mode pin. a logic controlled input to select either automatic burst mode operation or forced ? xed frequency operation. mode = high: burst mode operation at light loads mode = low: fixed frequency pwm mode v out (pin 8): output voltage sense and drain of the internal synchronous recti? er. pcb trace length from v out to the output ? lter capacitor should be as short and wide as possible. exposed pad (pin 9): the exposed pad must be soldered to the pcb ground plane. it serves as another ground connection, and as a means of conducting heat away from the die. C + C + 3539 bd sw shdn v out v out exposed pad wake burst i zero soft-start error amplifier/sleep comparator i pk comparator i zero comparator slope comparator i pk gnd v in v in mode fb fb r2 + C logic and burst mode control gate drivers and anti-cross conduction thermal shutdown start-up clamp shutdown shutdown v best v out v b v sel uvlo uvlo tsd v ref v ref v ref 3 well switch r1 1mhz/2mhz osc clk burst pwm on off 1 4 8 6 3 pgnd 2 9 7 5
LTC3539/LTC3539-2 7 3539f operation detailed description the LTC3539 is a high power synchronous boost converter in an 8-lead 2mm 3mm dfn package. with the ability to start up and operate from inputs of 700mv, the device features ? xed frequency, current mode pwm control for exceptional line and load regulation. the current mode architecture with adaptive slope compensation provides excellent transient load response, requiring minimal output ? ltering. internal soft-start and internal loop compensa- tion simpli? es the design process while minimizing the number of external components. the switching frequency of the LTC3539 is nominally 1mhz, while the LTC3539-2 switches at 2mhz. operation of the LTC3539 and LTC3539-2 is identical in all other respects. with its low r ds(on) and low gate charge internal n-chan- nel mosfet switch and p-channel mosfet synchronous recti? er, the LTC3539 achieves high ef? ciency over a wide range of load current. burst mode operation maintains high ef? ciency at very light loads, reducing the quiescent current to just 10a. converter operation can be best understood by referring to the block diagram. low voltage start-up the LTC3539 includes an independent start-up oscillator designed to start up at an input voltage of 0.7v (typical). soft-start and inrush current limiting are provided during start-up, as well as normal mode. when either v in or v out exceeds 1.4v typical, the ic enters normal operating mode. once the output voltage exceeds the input by 0.24v, the ic powers itself from v out instead of v in . at this point the internal circuitry has no dependency on the v in input voltage, eliminating the requirement for a large input capacitor. the input voltage can drop as low as 0.5v. the limiting factor for the appli- cation becomes the ability of the power source to supply suf? cient energy to the output at the low voltages, and the maximum duty cycle, which is clamped at 90% typical. note that at low input voltages, small voltage drops due to series resistance become critical, and greatly limit the power delivery capability of the converter. low noise fixed frequency operation soft-start: the LTC3539/LTC3539-2 contains internal circuitry to provide soft-start operation. the internal soft-start circuitry ramps the peak inductor current from zero to its peak value of 2.6a (typical) in approximately 0.5ms, allowing start-up into heavy loads. the soft-start circuitry is reset in the event of a thermal shutdown or shutdown command. oscillator: an internal oscillator sets the switching frequency to 1mhz for the LTC3539, and 2mhz for the LTC3539-2. shutdown: the part is shutdown by pulling the shdn pin below 0.3v, and activated by pulling the shdn pin above 0.88v. note that shdn can be driven above v in or v out , as long as it is limited to less than the absolute maximum rating. error ampli? er: the error ampli? er is a transconductance type. the non-inverting input is internally connected to the 1.2v reference and the inverting input is connected to fb. clamps limit the minimum and maximum error amp output voltage for improved large signal transient response. power converter control loop compensation is provided internally. a voltage divider from v out to ground programs the output voltage via fb from 1.5v to 5.25v. v out = 1.2v ? [1 + (r2/r1)]. current sensing: lossless current sensing converts the peak current signal of the n-channel mosfet switch into a voltage which is summed with the internal slope compensation. the summed signal is compared to the error ampli? er output to provide a peak current control command for the pwm. current limit: the current limit comparator shuts off the n-channel mosfet switch once its threshold is reached. peak switch current is limited to approximately 2.6a, independent of input or output voltage, unless v out falls below 0.7v, in which case the current limit is cut in half.
LTC3539/LTC3539-2 8 3539f operation zero current comparator: the zero current comparator monitors the inductor current to the output and shuts off the synchronous recti? er once this current reduces to ap- proximately 40ma. this prevents the inductor current from reversing in polarity, improving ef? ciency at light loads. synchronous recti? er: the p-channel mosfet synchro- nous recti? er is disabled when v out is much less than v in . this is to control inrush current and to prevent inductor current from running away anti-ringing control: the anti-ringing control connects a resistor across the inductor to prevent high frequency ringing on the sw pin during discontinuous current mode operation. the ringing of the resonant circuit formed by l and c sw (capacitance on sw pin) is low energy, but can cause emi radiation. output disconnect: the LTC3539 is designed to allow true output disconnect by eliminating body diode conduction of the internal p-channel mosfet recti? er. this allows v out to go to zero volts during shutdown, drawing no current from the input source. it also provides inrush current limiting at turn-on, minimizing surge currents seen by the input supply. note that to obtain the advantages of output disconnect, there must not be an external schottky diode connected between the sw pin and v out . the output disconnect feature also allows v out to be pulled high, without any reverse current into a battery on v in . thermal shutdown: if the die temperature exceeds 160c, the device will go into thermal shutdown. all switches will be turned off and the internal soft-start capacitor will be discharged. the device will be enabled again when the die temperature drops by about 15c. burst mode operation when burst mode operation is enabled by bringing the mode pin above 0.88v, the LTC3539 will automatically enter burst mode operation at light load current, then return to ? xed frequency pwm mode when the load in- creases. refer to the typical performance characteristics to see the output load burst mode threshold vs v in . the load current at which burst mode operation is entered can be changed by adjusting the inductor value. raising the inductor value will lower the load current at which burst mode operation is entered. in burst mode operation, the LTC3539 still switches at a ? xed frequency, using the same error ampli? er and loop compensation for peak current mode control. this control method eliminates any output transient when switching between modes. in burst mode operation, energy is deliv- ered to the output until it reaches the nominal regulation value, then the LTC3539 transitions to sleep mode where the outputs are off and the LTC3539 consumes only 10a of quiescent current from v out . when the output voltage droops slightly, switching resumes. this maximizes ef- ? ciency at very light loads by minimizing switching and quiescent current losses. burst mode output voltage ripple, which is typically 1% peak to peak, can be reduced by using more output capacitance (47f or greater). as the load increases, the LTC3539 will automatically leave burst mode operation. once the LTC3539 has left burst mode operation and returned to normal operation, it will remain there until the output load is reduced below the burst threshold. burst mode operation is inhibited during start-up until soft-start is complete and v out is at least 0.24v greater than v in . when the mode pin is below 0.3v, the LTC3539 features continuous pwm operation. in this mode, at very light loads, the LTC3539 will exhibit pulse-skip operation. if the mode pin voltage exceeds the greater of v in or v out by 0.5v, the mode pin will sink additional current.
LTC3539/LTC3539-2 9 3539f applications information v in > v out operation the LTC3539 will maintain output voltage regulation even when the input voltage is above the desired output. note that the ef? ciency and the maximum output current capability are reduced. refer to typical performance characteristics. short-circuit protection the LTC3539 output disconnect feature allows an output short circuit while maintaining a maximum internally set current limit. to reduce power dissipation under short- circuit conditions, the peak switch current limit is reduced to 1.4a (typical). schottky diode although it is not required, adding a schottky diode from sw to v out will improve ef? ciency by about 2%. note that this defeats the output disconnect, v in > v out operation and short circuit protection features. pcb layout guidelines the high speed operation of the LTC3539 demands careful attention to board layout. a careless layout will result in reduced performance. figure 1 shows the recommended component placement. a large ground pin copper area will help to lower the die temperature. a multilayer board with a separate ground plane is ideal. component selection inductor selection the LTC3539 can utilize small surface mount and chip inductors due to the high switching frequency. inductor values between 3.3h and 4.7h for the LTC3539 and between 1.5h and 2.5h for the LTC3539-2 are suitable for most applications*. larger values of inductance will allow slightly greater output current capability (and lower the burst mode threshold) by reducing the inductor ripple current. however, increasing the inductance above 10h will increase size while providing little improvement in output current capability. the minimum inductance value is given by: l> vv v ripple v in min out max in min ou () ( ) () ?( ) ? ? t tmax f () ? where: f = 1 for the LTC3539 or 2.2 for the LTC3539-2 ripple = allowable inductor current ripple (amps peak-to-peak) v in(min) = minimum input voltage v out(max) = maximum output voltage the inductor current ripple is typically set for 20% to 40% of the maximum inductor current. high frequency ferrite core inductor materials improve ef? ciency by reducing frequency dependent power losses compared to cheaper powdered iron types. the inductor should have low esr (series resistance of the windings) to reduce the i 2 r power losses, and must accomodate the peak inductor current without saturating. molded chokes and some chip inductors usually do not have enough core area to support the peak inductor current of 2.6a seen on the LTC3539. to minimize radiated noise, use a shielded inductor. see table 1 for suggested suppliers and representative components. figure 1. recommended component placement for single layer board + sw LTC3539 1 gnd minimize trace on fb and sw 3 pgnd 2 v in multiple vias to ground plane v in v out fb shdn 3539 f01 4 8 6 mode 7 5 *single cell applications (v in < 1.6v) should use a 2.2h inductor for the LTC3539
LTC3539/LTC3539-2 10 3539f applications information table 1. representative inductors vendor part/style coilcraft (847) 639-6400 www.coilcraft.com mss5131 lps4018-222 mss6132 mos6020 murata www.murata.com lqh55d lqh66s sumida (847) 956-0666 www.sumida.com cdrh4d22 cdrh4d28c cdrh5d28 cdr6d23 tdk (847) 803-6100 www.component.tdk.com vlf5014st toko (408) 432-8282 www.tokoam.com d53lc d63lcb wurth (201) 785-8800 www.we-online.com we-tpc type lh, x we-pd type xs output and input capacitor selection the internal loop compensation of the LTC3539 is designed to be stable with output capacitor values of 10f or greater. although ceramic capacitors are recommended, low esr (equivalent series resistance) tantalum capacitors may be used as well. low esr capacitors should be used to minimize the output voltage ripple. multilayer ceramic capacitors are an excellent choice as they have extremely low esr and are available in small footprints. a 22f to 47f output capacitor is suf? cient for output voltages of 3v or greater. an output capacitor of up to 100f is required at lower output voltages. even with v out greater than 3v, larger values up to 100f may be used to obtain extremely low output voltage ripple and improve transient response. x5r and x7r dielectric materials are preferred for their ability to maintain capacitance over wide voltage and temperature ranges. y5v types should not be used. a small ceramic capacitor in parallel with a larger tantalum capacitor may be used in demanding applications which have large load transients. a feedforward capacitor across the top resistor of the feedback divider (from v out to fb) is usually required to improve transient response. a typical value of 22pf will generally suf? ce. low esr input capacitors reduce input switching noise and reduce the peak current drawn from the battery. it follows that ceramic capacitors are also a good choice for input decoupling and should be located as close as possible to the device. a 2.2f input capacitor is suf? cient for most applications. larger values may be used without limita- tions. table 2 shows a list of several ceramic capacitor manufacturers. consult the manufacturers directly for detailed information on their selection of ceramic parts. table 2. capacitor vendor information supplier phone website avx (803) 448-9411 www.avxcorp.com murata (714) 852-2001 www.murata.com taiyo-yuden (408) 573-4150 www.t-yuden.com tdk (847) 803-6100 www.component.tdk.com typical applications 1 cell to 1.8v 1 cell to 3.3v li-ion cell to 5v 3539 ta02 LTC3539 v in sw 2.2f v out 1.8v 500ma v in 1v to 1.6v 2.2h v out mode shdn fb pgnd gnd 1.91m 1m 22f* x5 *at high load currents, a tantalum capacitor will improve performance. 22pf burst pwm on off 3539 ta03 LTC3539 v in sw 2.2f v out 3.3v 350ma v in 0.9v to 1.6v 2.2h v out mode shdn fb pgnd gnd 562k 1m 22f x2 burst pwm on off 22pf 3539 ta04 LTC3539-2 v in sw 2.2f v out 5v 750ma v in 3v to 4.5v 2.2h v out mode shdn fb pgnd gnd 309k 1m 22f burst pwm on off 22pf
LTC3539/LTC3539-2 11 3539f 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 3.00 0.10 (2 sides) 2.00 0.10 (2 sides) note: 1. drawing is not a jedec package outline 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 viewexposed pad 0.75 0.05 r = 0.115 typ r = 0.05 typ 1.35 ref 1 4 8 5 pin 1 bar top mark (see note 6) 0.200 ref 0.00 C 0.05 (dcb8) dfn 0106 rev a 0.23 0.05 0.45 bsc pin 1 notch r = 0.20 or 0.25 45 chamfer 0.25 0.05 1.35 ref recommended solder pad pitch and dimensions apply solder mask to areas that are not soldered 2.10 0.05 0.70 0.05 3.50 0.05 package outline 0.45 bsc 1.35 0.10 1.35 0.05 1.65 0.10 1.65 0.05 dcb package 8-lead plastic dfn (2mm 3mm) (reference ltc dwg # 05-08-1718 rev a)
LTC3539/LTC3539-2 12 3539f linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com ? linear technology corporation 2008 lt 0408 ? printed in usa related parts part number description comments ltc3400/ ltc3400b 600ma i sw , 1.2mhz, synchronous step-up dc/dc converters 92% ef? ciency v in : 0.85v to 5v, v out(max) = 5v, i q = 19a/300a, i sd <1a, thinsot? package ltc3401 1a i sw , 3mhz, synchronous step-up dc/dc converter 97% ef? ciency v in : 0.5v to 5v, v out(max) = 6v, i q = 38a, i sd <1a, 10-lead ms package ltc3402 2a i sw , 3mhz, synchronous step-up dc/dc converter 97% ef? ciency v in : 0.5v to 5v, v out(max) = 6v, i q = 38a, i sd <1a, 10-lead ms package ltc3421 3a i sw , 3mhz, synchronous step-up dc/dc converter with output disconnect 95% ef? ciency v in : 0.5v to 4.5v, v out(max) = 5.25v, i q = 12a, i sd <1a, qfn24 package ltc3422 1.5a i sw , 3mhz synchronous step-up dc/dc converter with output disconnect 95% ef? ciency v in : 0.5v to 4.5v, v out(max) = 5.25v, i q = 25a, i sd <1a, 3mm 3mm dfn package ltc3423/ ltc3424 1a/2a i sw , 3mhz, synchronous step-up dc/dc converter 95% ef? ciency v in : 0.5v to 5.5v, v out(max) = 5.5v, i q = 38a, i sd <1a, 10-lead ms package ltc3426 2a i sw , 1.2mhz, step-up dc/dc converter 92% ef? ciency v in : 1.6v to 4.3v, v out(max) = 5v, i sd <1a, sot-23 package ltc3428 500ma i sw , 1.25mhz/2.5mhz, synchronous step-up dc/dc converters with output disconnect 92% ef? ciency v in : 1.8v to 5v, v out(max) = 5.25v, i sd <1a, 3mm 3mm dfn package ltc3429 600ma i sw , 500khz, synchronous step-up dc/dc converter with output disconnect and soft-start 96% ef? ciency v in : 0.5v to 4.4v, v out(max) = 5v, i q = 20a/300a, ltc3458 1.4a i sw , 1.5mhz, synchronous step-up dc/dc converter/output disconnect/burst mode operation 93% ef? ciency v in : 1.5v to 6v, v out(max) = 7.5v, i q = 15a, i sd <1a, dfn12 package ltc3458l 1.7a i sw , 1.5mhz, synchronous step-up dc/dc converter with output disconnect, automatic burst mode operation 94% ef? ciency v out(max) = 6v, i q = 12a, dfn12 package ltc3459 70ma i sw , 10v micropower synchronous boost converter/output disconnect/burst mode operation v in : 1.5v to 5.5v, v out(max) = 10v, i q = 10a, i sd <1a, thinsot package ltc3525-3/ ltc3525-3.3/ ltc3525-5 400ma micropower synchronous step-up dc/dc converter with output disconnect 95% ef? ciency v in : 1v to 4.5v, v out(max) = 3.3v or 5v, i q = 7a, i sd <1a, sc-70 package ltc3525l-3 400ma micropower synchronous step-up dc/dc converter with output disconnect 95% ef? ciency v in : 0.88v to 4.5v, v out(max) = 3v, i q = 7a, i sd <1a, sc-70 package ltc3526/ ltc3526b 500ma, 1mhz synchronous step-up dc/dc converter with output disconnect 94% ef? ciency v in : 0.85v to 5v, v out(max) = 5.25v, i q = 9a, i sd <1a, 2mm 2mm dfn-6 package ltc3526l 550ma, 1mhz synchronous step-up dc/dc converter with output disconnect 94% ef? ciency v in : 0.68v to 5v, v out(max) = 5.25v, i q = 9a, i sd <1a, 2mm 2mm dfn-6 package ltc3527/ ltc3527-1 dual 800ma/400ma, 1.2mhz/2.2mhz synchronous step-up dc/dc converter with output disconnect 94% ef? ciency v in : 0.68v to 5v, v out(max) = 5.25v, i q = 12a, i sd <1a, 3mm 3mm qfn-16 package ltc3528/ ltc3528b 1a, 1mhz synchronous step-up dc/dc converter with output disconnect 94% ef? ciency v in : 0.68v to 5v, v out(max) = 5.25v, i q = 12a, i sd <1a, 2mm 3mm dfn-8 package thinsot is a trademark of linear technology corporation.

▲Up To Search▲

Price & Availability of LTC3539

	To Download LTC3539 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .