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1 LT1930/LT1930a applicatio s u features descriptio u typical applicatio u 1a, 1.2mhz/2.2mhz, step-up dc/dc converters in thinsot n 1.2mhz switching frequency (LT1930) n 2.2mhz switching frequency (LT1930a) n low v cesat switch: 400mv at 1a n high output voltage: up to 34v n 5v at 480ma from 3.3v input (LT1930) n 12v at 250ma from 5v input (LT1930a) n wide input range: 2.6v to 16v n uses small surface mount components n low shutdown current: < 1 m a n low profile (1mm) thinsot tm package n pin-for-pin compatible with the lt1613 figure 1. 5v to 12v, 300ma step-up dc/dc converter n tft-lcd bias supply n digital cameras n cordless phones n battery backup n medical diagnostic equipment n local 5v or 12v supply n external modems n pc cards n xdsl power supply efficiency the lt ? 1930 and LT1930a are the industrys highest power sot-23 switching regulators. both include an internal 1a, 36v switch allowing high current outputs to be generated in a small footprint. the LT1930 switches at 1.2mhz, allowing the use of tiny, low cost and low height capacitors and inductors. the faster LT1930a switches at 2.2mhz, enabling further reductions in inductor size. complete regulator solutions approaching one tenth of a square inch in area are achievable with these devices. multiple output power supplies can now use a separate regulator for each output voltage, replacing cumbersome quasi-regulated approaches using a single regulator and custom transformers. a constant frequency internally compensated current mode pwm architecture results in low, predictable output noise that is easy to filter. low esr ceramic capacitors can be used at the output, further reducing noise to the millivolt level. the high voltage switch on the LT1930/LT1930a is rated at 36v, making the device ideal for boost converters up to 34v as well as for single-ended primary inductance converter (sepic) and flyback designs. the LT1930 can generate 5v at up to 480ma from a 3.3v supply or 5v at 300ma from four alkaline cells in a sepic design. the LT1930/LT1930a are available in the 5-lead thinsot package. gnd v in sw shdn fb v in 5v 4 51 3 d1 l1 10 h 2 r1 113k LT1930 1930/a f01 c2 4.7 f c3* 10pf c1 2.2 f r2 13.3k v out 12v 300ma c1: taiyo-yuden x5r lmk212bj225mg c2: taiyo-yuden x5r emk316bj475ml d1: on semiconductor mbr0520 l1: sumida cr43-100 *optional shdn load current (ma) 0 efficiency (%) 70 75 80 400 1930 ta01 65 60 50 100 200 300 55 90 85 v in = 5v v in = 3.3v , ltc and lt are registered trademarks of linear technology corporation thinsot is a trademark of linear technology corporation.
2 LT1930/LT1930a (note 1) v in voltage .............................................................. 16v sw voltage ................................................C 0.4v to 36v fb voltage .............................................................. 2.5v current into fb pin .............................................. 1ma shdn voltage ......................................................... 10v maximum junction temperature ......................... 125 c operating temperature range (note 2) .. C 40 c to 85 c storage temperature range ................. C 65 c to 150 c lead temperature (soldering, 10 sec).................. 300 c the l denotes specifications which apply over the full operating temperature range, otherwise specifications are t a = 25 c. v in = 3v, v shdn = v in unless otherwise noted. (note 2) order part number LT1930es5 LT1930aes5 s5 part marking ltks ltsq t jmax = 125 c, q ja = 256 c/ w electrical characteristics package/order i for atio uu w absolute axi u rati gs w ww u note 1: absolute maximum ratings are those values beyond which the life of a device may be impaired. note 2: the LT1930e/LT1930ae are guaranteed to meet performance specifications from 0 c to 70 c. specifications over the C 40 c to 85 c operating temperature range are assured by design, characterization and correlation with statistical process controls. note 3: current limit guaranteed by design and/or correlation to static test. consult ltc marketing for parts specified with wider operating temperature ranges. sw 1 gnd 2 top view s5 package 5-lead plastic sot-23 fb 3 5 v in 4 shdn LT1930 LT1930a parameter conditions min typ max min typ max units minimum operating voltage 2.45 2.6 2.45 2.6 v maximum operating voltage 16 16 v feedback voltage 1.240 1.255 1.270 1.240 1.255 1.270 v l 1.230 1.280 1.230 1.280 v fb pin bias current v fb = 1.255v l 120 360 240 720 na quiescent current v shdn = 2.4v, not switching 4.2 6 5.5 8 ma quiescent current in shutdown v shdn = 0v, v in = 3v 0.01 1 0.01 1 m a reference line regulation 2.6v v in 16v 0.01 0.05 0.01 0.05 %/v switching frequency 1 1.2 1.4 1.8 2.2 2.6 mhz l 0.85 1.6 1.6 2.9 mhz maximum duty cycle l 84 90 75 90 % switch current limit (note 3) 1 1.2 2 1 1.2 2.5 a switch v cesat i sw = 1a 400 600 400 600 mv switch leakage current v sw = 5v 0.01 1 0.01 1 m a shdn input voltage high 2.4 2.4 v shdn input voltage low 0.5 0.5 v shdn pin bias current v shdn = 3v 16 32 35 70 m a v shdn = 0v 0 0.1 0 0.1 m a
3 LT1930/LT1930a typical perfor a ce characteristics uw quiescent current fb pin voltage shdn pin current current limit switch saturation voltage oscillator frequency sw (pin 1): switch pin. connect inductor/diode here. minimize trace area at this pin to reduce emi. gnd (pin 2): ground. tie directly to local ground plane. fb (pin 3): feedback pin. reference voltage is 1.255v. connect resistive divider tap here. minimize trace area at fb. set v out according to v out = 1.255v(1 + r1/r2). uu u pi fu ctio s shdn (pin 4): shutdown pin. tie to 2.4v or more to enable device. ground to shut down. v in (pin 5): input supply pin. must be locally bypassed. temperature ( c) ?0 25 quiescent current (ma) 50 75 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 1930/a g01 0 25 100 not switching LT1930a LT1930 temperature ( c) ?0 1.22 fb voltage (v) 1.23 1.24 1.25 1.26 1.28 ?5 02550 1930/a g02 75 100 1.27 shdn pin voltage (v) 0 shdn pin current ( a) 20 30 40 3 5 1930/a g03 10 0 ?0 12 4 50 60 70 80 90 6 LT1930a LT1930 duty cycle (%) 10 current li mit (a) 0.8 1.2 1930/a g04 0.4 0 30 20 50 40 70 60 90 80 1.6 0.6 1.0 0.2 1.4 switch current (a) 0 0 v cesat (v) 0.05 0.15 0.20 0.25 0.8 0.45 1930/a g05 0.10 0.4 1.2 0.6 0.2 1.0 0.30 0.35 0.40 temperature ( c) 50 ?5 0 frequency (mhz) 2.5 2.3 2.1 1.9 1.7 1.5 1.3 1.1 0.9 0.7 0.5 25 50 75 100 1930/a g06 LT1930 LT1930a
4 LT1930/LT1930a block diagra w figure 2. block diagram operatio u the LT1930 uses a constant frequency, current-mode control scheme to provide excellent line and load regula- tion. operation can be best understood by referring to the block diagram in figure 2. at the start of each oscillator cycle, the sr latch is set, which turns on the power switch q1. a voltage proportional to the switch current is added to a stabilizing ramp and the resulting sum is fed into the positive terminal of the pwm comparator a2. when this voltage exceeds the level at the negative input of a2, the sr latch is reset turning off the power switch. the level at the negative input of a2 is set by the error amplifier a1, and is simply an amplified version of the difference between the feedback voltage and the reference voltage of 1.255v. in this manner, the error amplifier sets the correct peak current level to keep the output in regulation. if the error amplifiers output increases, more current is delivered to the output; if it decreases, less current is delivered. the LT1930 has a current limit circuit not shown in figure 2. the switch current is constantly monitored and not al- lowed to exceed the maximum switch current (typically 1.2a). if the switch current reaches this value, the sr latch is reset regardless of the state of comparator a2. this current limit helps protect the power switch as well as the external components connected to the LT1930. the block diagram for the LT1930a (not shown) is iden- tical except that the oscillator frequency is 2.2mhz. + + rq s 0.01 w sw driver comparator 2 shdn 4 1 v in 5 fb 3 + s ramp generator 1.255v reference r c c c 1.2mhz oscillator* gnd 1930/a bd q1 a2 a1 r1 (external) r2 (external) fb v out shutdown *2.2mhz for LT1930a
5 LT1930/LT1930a applicatio n s i n for m atio n wu u u LT1930 and LT1930a differences switching frequency the key difference between the LT1930 and LT1930a is the faster switching frequency of the LT1930a. at 2.2mhz, the LT1930a switches at nearly twice the rate of the LT1930. care must be taken in deciding which part to use. the high switching frequency of the LT1930a allows smaller cheaper inductors and capacitors to be used in a given application, but with a slight decrease in efficiency and maximum output current when compared to the LT1930. generally, if efficiency and maximum output current are critical, the LT1930 should be used. if applica- tion size and cost are more important, the LT1930a will be the better choice. in many applications, tiny inexpensive chip inductors can be used with the LT1930a, reducing solution cost. duty cycle the maximum duty cycle (dc) of the LT1930a is 75% compared to 84% for the LT1930. the duty cycle for a given application using the boost topology is given by: dc vv v out in out = |||| || for a 5v to 12v application, the dc is 58.3% indicating that the LT1930a could be used. a 5v to 24v application has a dc of 79.2% making the LT1930 the right choice. the LT1930a can still be used in applications where the dc, as calculated above, is above 75%. however, the part must be operated in the discontinuous conduction mode so that the actual duty cycle is reduced. inductor selection several inductors that work well with the LT1930 are listed in table 1 and those for the LT1930a are listed in table 2. these tables are not complete, and there are many other manufacturers and devices that can be used. consult each manufacturer for more detailed information and for their entire selection of related parts, as many different sizes and shapes are available. ferrite core inductors should be used to obtain the best efficiency, as core losses at 1.2mhz are much lower for ferrite cores than for cheaper powdered- iron types. choose an inductor that can handle at least 1a without saturating, and ensure that the inductor has a low dcr (copper-wire resistance) to minimize i 2 r power losses. a 4.7 m h or 10 m h inductor will be the best choice for most LT1930 designs. for LT1930a designs, a 2.2 m h to 4.7 m h inductor will usually suffice. note that in some applica- tions, the current handling requirements of the inductor can be lower, such as in the sepic topology where each inductor only carries one-half of the total switch current. table 1. recommended inductors C LT1930 max size l dcr l w h part ( m h) m w (mm) vendor cdrh5d18-4r1 4.1 57 4.5 4.7 2.0 sumida cdrh5d18-100 10 124 (847) 956-0666 cr43-4r7 4.7 109 3.2 2.5 2.0 www.sumida.com cr43-100 10 182 ds1608-472 4.7 60 4.5 6.6 2.9 coilcraft ds1608-103 10 75 (847) 639-6400 www.coilcraft.com elt5kt4r7m 4.7 240 5.2 5.2 1.1 panasonic elt5kt6r8m 6.8 360 (408) 945-5660 www.panasonic.com table 2. recommended inductors C LT1930a max size l dcr l w h part ( m h) m w (mm) vendor lqh3c2r2m24 2.2 126 3.2 2.5 2.0 murata lqh3c4r7m24 4.7 195 (404) 573-4150 www.murata.com cr43-2r2 2.2 71 4.5 4.0 3.0 sumida cr43-3r3 3.3 86 (847) 956-0666 www.sumida.com 1008ps-272 2.7 100 3.7 3.7 2.6 coilcraft 1008ps-332 3.3 110 (800) 322-2645 www.coilcraft.com elt5kt3r3m 3.3 204 5.2 5.2 1.1 panasonic (408) 945-5660 www.panasonic.com the inductors shown in table 2 for use with the LT1930a were chosen for small size. for better efficiency, use similar valued inductors with a larger volume. for example, the sumida cr43 series in values ranging from 2.2 m h to 4.7 m h will give an LT1930a application a few percentage points increase in efficiency, compared to the smaller murata lqh3c series.
6 LT1930/LT1930a applicatio n s i n for m atio n wu u u capacitor selection low esr (equivalent series resistance) capacitors should be used at the output to minimize the output ripple voltage. multi-layer ceramic capacitors are an excellent choice, as they have extremely low esr and are available in very small packages. x5r dielectrics are preferred, followed by x7r, as these materials retain the capacitance over wide voltage and temperature ranges. a 4.7 m f to 10 m f output capacitor is sufficient for most applications, but systems with very low output currents may need only a 1 m f or 2.2 m f output capacitor. solid tantalum or oscon capacitors can be used, but they will occupy more board area than a ceramic and will have a higher esr. always use a capacitor with a sufficient voltage rating. ceramic capacitors also make a good choice for the input decoupling capacitor, which should be placed as close as possible to the LT1930/LT1930a. a 1 m f to 4.7 m f input capacitor is sufficient for most applications. table 3 shows a list of several ceramic capacitor manufacturers. consult the manufacturers for detailed information on their entire selection of ceramic parts. table 3. ceramic capacitor manufacturers taiyo yuden (408) 573-4150 www.t-yuden.com avx (803) 448-9411 www.avxcorp.com murata (714) 852-2001 www.murata.com the decision to use either low esr (ceramic) capacitors or the higher esr (tantalum or oscon) capacitors can affect the stability of the overall system. the esr of any capaci- tor, along with the capacitance itself, contributes a zero to the system. for the tantalum and oscon capacitors, this zero is located at a lower frequency due to the higher value of the esr, while the zero of a ceramic capacitor is at a much higher frequency and can generally be ignored. a phase lead zero can be intentionally introduced by placing a capacitor (c3) in parallel with the resistor (r1) between v out and v fb as shown in figure 1. the frequency of the zero is determined by the following equation. |= z rc 1 213 p by choosing the appropriate values for the resistor and capacitor, the zero frequency can be designed to improve the phase margin of the overall converter. the typical target value for the zero frequency is between 35khz to 55khz. figure 3 shows the transient response of the step- up converter from figure 1 without the phase lead capaci- tor c3. the phase margin is reduced as evidenced by more ringing in both the output voltage and inductor current. a 10pf capacitor for c3 results in better phase margin, which is revealed in figure 4 as a more damped response and less overshoot. figure 5 shows the transient response when a 33 m f tantalum capacitor with no phase lead capacitor is used on the output. the higher output voltage ripple is revealed in the upper waveform as a set of double lines. the transient response is not greatly improved which implies that the esr zero frequency is too high to increase the phase margin. v out 0.2v/div ac coupled i li 0.5a/div ac coupled 250ma 150ma load current 50 m s/div 1930 f03 figure 3. transient response of figure 1's step-up converter without phase lead capacitor figure 4. transient response of figure 1's step-up converter with 10pf phase lead capacitor v out 0.2v/div ac coupled i li 0.5a/div ac coupled 250ma 150ma load current 50 m s/div 1930 f04
7 LT1930/LT1930a figure 5. transient response of step-up converter with 33 m f tantalum output capacitor and no phase lead capacitor v out 0.2v/div ac coupled i li 0.5a/div ac coupled 250ma 150ma load current 200 m s/div 1930 f04 diode selection a schottky diode is recommended for use with the LT1930/ LT1930a. the motorola mbr0520 is a very good choice. where the switch voltage exceeds 20v, use the mbr0530 (a 30v diode). where the switch voltage exceeds 30v, use the mbr0540 (a 40v diode). these diodes are rated to handle an average forward current of 0.5a. in applications where the average forward current of the diode exceeds 0.5a, a microsemi ups5817 rated at 1a is recommended. setting output voltage to set the output voltage, select the values of r1 and r2 (see figure 1) according to the following equation. rr v v out 12 1 255 1 = ? ? ? ? . a good value for r2 is 13.3k which sets the current in the resistor divider chain to 1.255v/13.3k = 94.7 m a. figure 6. suggested layout r1 r2 gnd c3 c2 l1 d1 c1 v out v in shutdown 1930 f06 + + gnd v in sw shdn fb v in 16v 4 51 3 d1 l1 2 r1 LT1930 1930 f07 c2 c1 121k r2 v out figure 7. keeping shdn below 10v layout hints the high speed operation of the LT1930/LT1930a demands careful attention to board layout. you will not get advertised performance with careless layout. figure 6 shows the recommended component placement. driving shdn above 10v the maximum voltage allowed on the shdn pin is 10v. if you wish to use a higher voltage, you must place a resistor in series with shdn. a good value is 121k. figure 7 shows a circuit where v in = 16v and shdn is obtained from v in . the voltage on the shdn pin is kept below 10v. applicatio n s i n for m atio n wu u u
8 LT1930/LT1930a typical applicatio s u efficiency gnd v in sw shdn fb 4v to 6.5v 4 51 3 d1 l1 10 h l2 10 h 2 243k LT1930 1930 ta02a c1 2.2 f 4-cell battery c2 10 f c3 1 f 82.5k v out 5v 300ma c1: taiyo-yuden x5r lmk212bj225mg c2: taiyo-yuden x5r jmk316bj106ml c3: taiyo-yuden x5r lmk212bj105mg shdn d1: on semiconductor mbr0520 l1, l2: murata lqh3c100k24 load current (ma) 0 efficiency (%) 60 65 70 400 500 1930 ta02b 55 50 40 100 200 300 45 80 75 v in = 6.5v v in = 4v 4-cell to 5v sepic converter 4-cell to 5v sepic converter with coupled inductors gnd v in sw shdn fb 4v to 6.5v 4 51 3 d1 l1a 10 h l1b 10 h 2 243k LT1930 1930/a ta03 c1 2.2 f 4-cell battery c2 10 f c3 1 f 82.5k v out 5v 300ma c1: taiyo-yuden x5r lmk212bj225mg c2: taiyo-yuden x5r jmk316bj106ml c3: taiyo-yuden x5r lmk212bj105mg d1: on semiconductor mbr0520 l1: sumida cls62-100 shdn gnd v in sw shdn fb v in 5v 4 51 3 d1 l1 10 h 2 r1 665k LT1930 1930/a ta04 c2 2.2 f c1 4.7 f r2 36.5k v out 24v 90ma c1: taiyo-yuden x5r emk316bj475ml c2: taiyo-yuden x5r jmk212bj475mg d1: on semiconductor mbr0530 l1: sumida cr43-100 shdn 5v to 24v boost converter gnd v in sw shdn fb v in 5v 4 51 3 d1 c4 1 f d2 l1 3.3 h 2 r1 147k c5 1 f LT1930 d3 d4 1930/a ta05 c2 2.2 f c6 2.2 f c1 2.2 f r2 13.3k 15v 70ma 15v 70ma c1: taiyo-yuden x5r lmk212bj225mg c2, c3: taiyo-yuden x5r emk316bj225ml c4, c5: taiyo-yuden x5r tmk316bj105ml (408) 573-4150 d1 to d4: on semiconductor mbr0520 (800) 282-9855 l1: sumida cr43-3r3 (874) 956-0666 off on 15v dual output converter with output disconnect
9 LT1930/LT1930a typical applicatio s u gnd v in sw shdn fb v in 3.3v 4 51 3 d1 l1 5.6 h 2 r1 40.2k LT1930 1930/a ta07a c2 10 f c1 4.7 f r2 13.3k v out 5v 480ma c1: taiyo-yuden x5r jmk212bj475mg www.t-yuden.com c2: taiyo-yuden x5r jmk316bj106ml d1: on semiconductor mbr0520 www.onsemi.com l1: sumida cr43-5r6 www.sumida.com off on load current (ma) 0 efficiency (%) 65 70 75 300 500 1930/a ta07b 60 55 50 100 200 400 80 85 90 v in = 3.3v v in = 2.6v efficiency 3.3v to 5v boost converter gnd v in sw shdn fb 4 51 3 d1 m1 l1 4.7 h 2 r1 60.4k r2 11.3k LT1930 1930/a ta06 c1 2.2 f v in 3v to 6v c2 22 f c3 47pf v out 8v 520ma at v in = 6v 240ma at v in = 3v c1: taiyo-yuden x5r lmk432bj226mm c2: taiyo-yuden x5r lmk212bj225mg d1: on semiconductor mbr0520 l1: sumida cr43-4r7 m1: siliconix si6433dq shdn boost converter with reverse battery protection gnd v in sw shdn fb v in 5v 4 51 3 d1 l1 2.2 h 2 r1 115k LT1930a 1930/a ta08a c2 2.2 f c1 2.2 f r2 13.3k v out 12v 250ma c1: taiyo-yuden x5r lmk212bj225mg c2: taiyo-yuden x5r emk316bj225ml d1: on semiconductor mbr0520 l1: murata lqh3c2r2m24 shdn load current (ma) 0 efficiency (%) 65 70 75 150 250 1930/a ta08b 60 55 50 50 100 200 80 85 90 300 v in = 5v v out = 12v 5v to 12v, 250ma step-up converter efficiency
10 LT1930/LT1930a typical applicatio s u gnd v in sw shdn fb v in 3.3v 4 51 3 d5 l1 4.7 h 2 r1 124k LT1930 1930/a ta11a c5 10 f c4 1 f c1 2.2 f c2 0.1 f c6 1 f r2 20k 9v 200ma ?v 10ma 18v 10ma c1: x5r or x7r, 6.3v c2,c3, c5: x5r or x7r, 10v c4: x5r or x7r, 25v d1- d4: bat54s or equivalent d5: mbr0520 or equivalent l1: panasonic elt5kt4r7m 3.3v 0v v ss d ss 1n4148 r ss 30k c ss 68nf d1 d4 d3 d2 c3 0.1 f + gnd v in sw shdn fb v in 3.3v 4 51 3 d7 l1 4.7 h 2 r1 113k LT1930 1930/a ta12a c7 10 f c6 1 f c1 2.2 f c2 0.1 f c8 1 f r2 21k 8v 220ma ?v 10ma 23v 10ma c1: x5r or x7r, 6.3v c2-c4, c7, c8: x5r or x7r, 10v c5: x5r or x7r, 16v c6: x5r or x7r, 25v d1- d6: bat54s or equivalent d7: mbr0520 or equivalent l1: panasonic elt5kt4r7m 3.3v 0v v ss d ss 1n4148 r ss 30k c ss 68nf d1 d5 d6 d2 c3 0.1 f c4 0.1 f c5 0.1 f d3 d4 + 8v, 23v, C8v triple output tft-lcd bias supply with soft-start 9v, 18v, C9v triple output tft-lcd bias supply with soft-start start-up waveforms start-up waveforms 9v output 5v/div C9v output 5v/div 18v output 10v/div i l1 0.5a/div 2ms/div 8v output 5v/div C8v output 5v/div 23v output 10v/div i l1 0.5a/div 2ms/div
11 LT1930/LT1930a u package descriptio 1.50 ?1.75 (.059 ?.069) (note 3) 2.60 ?3.00 (.102 ?.118) .25 ?.50 (.010 ?.020) (5plcs, note 2) l datum ? .09 ?.20 (.004 ?.008) (note 2) a1 s5 sot-23 0401 pin one 2.80 ?3.10 (.110 ?.118) (note 3) .95 (.037) ref a a2 1.90 (.074) ref .20 (.008) .90 ?1.45 (.035 ?.057) sot-23 (original) .00 ?.15 (.00 ?.006) .90 ?1.30 (.035 ?.051) .35 ?.55 (.014 ?.021) 1.00 max (.039 max) sot-23 (thinsot) a a1 a2 l .01 ?.10 (.0004 ?.004) .80 ?.90 (.031 ?.035) .30 ?.50 ref (.012 ?.019 ref) millimeters (inches) note: 1. controlling dimension: millimeters 2. dimensions are in 3. drawing not to scale 4. dimensions are inclusive of plating 5. dimensions are exclusive of mold flash and metal burr 6. mold flash shall not exceed .254mm 7. package eiaj reference is: sc-74a (eiaj) for original jedel mo-193 for thin 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. s5 package 5-lead plastic sot-23 (reference ltc dwg # 05-08-1633) (reference ltc dwg # 05-08-1635)
12 LT1930/LT1930a 1930af lt/tp 0801 2k ? printed in usa ? linear technology corporation 2001 linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 l fax: (408) 434-0507 l www.linear.com related parts part number description comments lt1307 single cell micropower 600khz pwm dc/dc converter 3.3v at 75ma from single cell, msop package lt1316 burst mode tm operation dc/dc converter with programmable current limit 1.5v minimum, precise control of peak current limit lt1317 2-cell micropower dc/dc converter with low-battery detector 3.3v at 200ma from 2 cells, 600khz fixed frequency lt1610 single cell micropower dc/dc converter 3v at 30ma from 1v, 1.7mhz fixed frequency lt1611 inverting 1.4mhz switching regulator in 5-lead thinsot C 5v at 150ma from 5v input, thinsot package lt1613 1.4mhz switching regulator in 5-lead thinsot 5v at 200ma from 3.3v input, thinsot package lt1615 micropower constant off-time dc/dc converter in 5-lead thinsot 20v at 12ma from 2.5v, thinsot package lt1617 micropower inverting dc/dc converter in 5-lead thinsot C15v at 12ma from 2.5v input, thinsot package lt1931/lt1931a inverting 1.2mhz/2.2mhz switching regulator in 5-lead thinsot C 5v at 350ma from 5v input, thinsot package burst mode is a trademark of linear technology corporation. typical applicatio u 3.3v to 5v transient response v out 50mv/div ac coupled i li 0.5a/div ac coupled 300ma 200ma load current 20 m s/div 1930 f03 gnd v in sw shdn fb v in 3.3v 4 51 3 d1 l1 2.2 h 2 r1 30.1k LT1930a 1930/a ta09a c2 10 f c1 2.2 f r2 10k v out 5v 450ma c1: taiyo-yuden x5r lmk212bj225mg c2: taiyo-yuden x5r jmk316b106ml d1: on semiconductor mbr0520 l1: murata lqh3c2r2m24 shdn load current (ma) 0 efficiency (%) 65 70 75 300 500 1930/a ta09b 60 55 50 100 200 400 80 85 90 v in = 3.3v v out = 5v efficiency 3.3v to 5v, 450ma step-up converter

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