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1 lt1304/lt1304-3.3/lt1304-5 micropower dc/dc converters with low-battery detector active in shutdown the lt ? 1304 is a micropower step-up dc/dc converter ideal for use in small, low voltage, battery-operated sys- tems. the devices operate from a wide input supply range of 1.5v to 8v. the lt1304-3.3 and lt1304-5 generate regulated outputs of 3.3v and 5v and the adjustable lt1304 can deliver output voltages up to 25v. quiescent current, 120 m a in active mode, decreases to just 10 m a in shutdown with the low-battery detector still active. peak switch current, internally set at 1a, can be reduced by adding a single resistor from the i lim pin to ground. the high speed operation of the lt1304 allows the use of small, surface-mountable inductors and capacitors. the lt1304 is available in an 8-lead so package. , ltc and lt are registered trademarks of linear technology corporation. applicatio n s u n 2-, 3-, or 4-cell to 5v or 3.3v step-up n portable instruments n bar code scanners n palmtop computers n diagnostic medical instrumentation n personal data communicators/computers n 5v at 200ma from two cells n 10 m a quiescent current in shutdown n operates with v in as low as 1.5v n low-battery detector active in shutdown n low switch v cesat : 370mv at 1a typical n 120 m a quiescent current in active mode n switching frequency up to 300khz n programmable peak current with one resistor n 8-lead so package features descriptio n u typical applicatio n u efficiency load current (ma) 40 50 60 70 80 90 efficiency (%) 1304 ta02 0.1 1 10 500 100 v in = 3.3v v in = 2.5v v in = 1.8v v in sw shdn gnd sense lbi 34 8 2 5 7 6 1 lbo i lim lt1304-5 + + 100k 100 m f nc * ** 604k 100 m f 2 cells 499k 22 m h* d1** 5v 200ma lbo low when v bat < 2.2v sumida cd54-220 1n5817 1304 ta01 shutdown 2-cell to 5v step-up converter with low-battery detect
2 lt1304/lt1304-3.3/lt1304-5 absolute m axi m u m ratings w ww u package/order i n for m atio n w u u v in voltage ................................................................ 8v sw voltage ............................................... C 0.4v to 25v fb voltage (lt1304) ...................................... v in + 0.3v sense voltage (lt1304-3.3/lt1304-5) ..................... 8v i lim voltage .............................................................. 5v shdn voltage ............................................................ 6v lbi voltage ............................................................... v in lbo voltage ............................................................... 8v maximum power dissipation ............................. 500mw junction temperature.......................................... 125 c operating temperature range ..................... 0 c to 70 c storage temperature range ................. C 65 c to 150 c lead temperature (soldering, 10 sec).................. 300 c lt1304cs8 lt1304cs8-3.3 LT1304CS8-5 1304 13043 13045 s8 part marking order part number 1 2 3 4 8 7 6 5 top view lbi lbo v in sw fb (sense)* shdn i lim gnd s8 package 8-lead plastic so *fixed output version t jmax = 125 c, q ja = 150 c/w parameter conditions min typ max units minimum operating voltage l 1.5 1.65 v operating voltage range l 8v quiescent current v shdn = 2v, not switching l 120 200 m a quiescent current in shutdown v shdn = 0v, v in = 2v l 715 m a v shdn = 0v, v in = 5v l 27 50 m a comparator trip point lt1304 l 1.22 1.24 1.26 v fb pin bias current lt1304 l 10 25 na sense pin leakage in shutdown v shdn = 0v, fixed output versions l 0.002 1 m a output sense voltage lt1304-3.3 l 3.17 3.3 3.43 v lt1304-5 l 4.80 5.05 5.25 v line regulation 1.8v v in 8v l 0.04 0.15 %/v lbi input threshold falling edge l 1.10 1.17 1.25 v lbi bias current l 620 na lbi input hysteresis l 35 65 mv lbo output voltage low i sink = 500 m a l 0.2 0.4 v lbo output leakage current lbi = 1.5v, lbo = 5v l 0.01 0.1 m a shdn input voltage high l 1.4 v shdn input voltage low l 0.4 v shdn pin bias current v shdn = 5v l 58 m a v shdn = 0v l C5 C2 m a switch off time l 1 1.5 2 m s switch on time current limit not asserted l 468 m s maximum duty cycle current limit not asserted l 76 80 88 % peak switch current i lim pin open, v in = 5v 0.8 1 1.2 a 20k from i lim to gnd 500 ma v in = 2v, v shdn = 2v unless otherwise noted. e lectr ic al c c hara terist ics consult factory for industrial and military grade parts.
3 lt1304/lt1304-3.3/lt1304-5 v in = 2v, v shdn = 2v unless otherwise noted. e lectr ic al c c hara terist ics the l denotes specifications which apply over the 0 c to 70 c operating temperature range. parameter conditions min typ max units switch saturation voltage i sw = 1a 0.37 v i sw = 700ma l 0.26 0.35 v switch leakage switch off, v sw = 5v l 0.01 7 m a typical perfor m a n ce characteristics uw temperature ( c) ?0 25 time ( m s) 050 25 75 100 1304 g03 8 7 6 5 4 3 2 1 0 maximum on-time off-time on- and off-times supply current switch current (a) 0 saturation voltage (mv) 500 400 300 200 100 0 0.2 0.4 0.6 0.8 1304 g01 1.0 1.2 t a = 25 c temperature ( c) ?0 0 bias current (na) 4 6 8 10 12 14 ?5 0 25 50 1304 g05 75 16 18 20 2 100 feedback pin bias current feedback voltage temperature ( c) ?0 feedback voltage (v) 1.250 1.245 1.240 1.235 1.230 1.225 1.220 1.215 1.210 1.205 1.200 ?5 02550 1304 g04 75 100 temperature ( c) peak current (a) 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 1304 g02 ?0 ?5 0 25 50 75 100 peak switch current limit switch saturation voltage input voltage (v) 01 3 5 7 supply current ( m a) 24 6 8 1304 g06 300 250 200 150 100 50 0 v shdn = v in not switching v shdn = 0v t a = 25 c
4 lt1304/lt1304-3.3/lt1304-5 typical perfor m a n ce characteristics uw load transient response v out 100mv/div ac coupled i load 200ma 0 v sw 5v/div 100 m s/div 1304 g07 20 m s/div 1304 g08 v out 100mv/div ac coupled burst mode tm operation i l 500ma/div v in = 2.5v v out = 5v i load = 185ma l = 22 m h pi n fu n ctio n s uuu lbi (pin 1): low-battery detector input. when voltage on this pin is less than 1.17v, detector output is low. lbo (pin 2): low-battery detector output. open collector can sink up to 500 m a. low-battery detector remains active when device is shut down. v in (pin 3): input supply. must be bypassed close (< 0.2") to the pin. see required layout in the typical applications. sw (pin 4): collector of power npn. keep copper traces on this pin short and direct to minimize rfi. gnd (pin 5): device ground. must be low impedance; solder directly to ground plane. i lim (pin 6): current limit set pin. float for 1a peak switch current; a resistor to ground will lower peak current. shdn (pin 7): shutdown input. when low, switching regulator is turned off. the low-battery detector remains active. the shdn input should not be left floating. if shdn is not used, tie the pin to v in . fb/sense (pin 8): on the lt1304 (adjustable) this pin goes to the comparator input. on the fixed-output ver- sions, the pin connects to the resistor divider which sets output voltage. the divider is disconnected from the pin during shutdown. burst mode is a trademark of linear technology corporation.
5 lt1304/lt1304-3.3/lt1304-5 w i dagra b l o c k s + 1304 f02 + + 1.17v r1 36mv a3 off lbi sense enable a2 lb0 sw gnd i lim shdn a1 8 6 5 4 v in 3 7 1 1.5v undervoltage lockout q3 q2 1 q1 200 r2 1k 590k r1 7.2 w 1k driver bias ~1v 2 1.24v v ref shutdown timers 6 s on 1.5 s off r1 = 355k (lt1304-3.3), 195k (lt1304-5) figure 2. lt1304-3.3/lt1304-5 block diagram + 1304 f01 + + 1.17v r4 36mv a3 off lbi enable a2 lb0 c1 l1 sw gnd i lim shdn fb a1 8 6 5 4 v in v out v in 3 7 1 1.5v undervoltage lockout q3 q2 1 q1 200 r2 1k r3 r1 7.2 w 1k driver bias ~1v 2 1.24v v ref shutdown + c2 d1 + timers 6 s on 1.5 s off figure 1. lt1304 block diagram. independent low-battery detector a3 remains alive when device is in shutdown
6 lt1304/lt1304-3.3/lt1304-5 operatio u the lt1304s operation can best be understood by exam- ining the block diagram in figure 1. comparator a1 monitors the output voltage via resistor divider string r3/r4 at the fb pin. when v fb is higher than the 1.24v reference, a2 and the timers are turned off. only the reference, a1 and a3 consume current, typically 120 m a. as v fb drops below 1.24v plus a1s hysteresis (about 6mv), a1 enables the rest of the circuit. power switch q1 is then cycled on for 6 m s, or until current comparator a2 turns off the on timer, whichever comes first. off-time is fixed at approximately 1.5 m s. q1s switching causes cur- rent to alternately build up in inductor l1 and discharge into output capacitor c2 via d1, increasing the output voltage. as v fb increases enough to overcome c1s hys- teresis, switching action ceases. c2 is left to supply current to the load until v out decreases enough to force a1s output high, and the entire cycle repeats. if switch current reaches 1a, causing a2 to trip, switch on time is reduced. this allows continuous mode opera- tion during bursts. a2 monitors the voltage across 7.2 w resistor r1, which is directly related to the switch current. q2s collector current is set by the emitter-area ratio to 0.5% of q1s collector current. r1s voltage drop exceeds 36mv, corresponding to 1a switch current, a2s output goes high, truncating the on time part of the switch cycle. the 1a peak current can be reduced by tying a resistor between the i lim pin and ground, causing a voltage drop to appear across r2. the drop offsets some of the 36mv reference voltage, lowering peak current. a 22k resistor limits current to approximately 550ma. a capacitor con- nected between i lim and ground provides soft start. shut- down is accomplished by grounding the shdn pin. the low-battery detector a3 has its own 1.17v reference and is always on. the open collector output device can sink up to 500 m a. approximately 35mv of hysteresis is built into a3 to reduce buzzing as the battery voltage reaches the trip level. inductor selection inductors used with the lt1304 must be capable of handling the worst-case peak switch current of 1.2a without saturating. open flux rod or drum core units may be biased into saturation by 20% with only a small reduc- tion in efficiency. for the majority of 2-cell or 3-cell input lt1304 applications, a 22 m h or 20 m h inductor such as the sumida cd54-220 (drum) or coiltronics ctx20-1 (toroid) will suffice. if switch current is reduced using the i lim pin, smaller inductors such as the sumida cd43 series or coilcraft do1608 series can be used. minimizing dcr is important for best efficiency. ideally, the inductor dcr should be less than 0.05 w , although the physical size of such an inductor makes its use prohibitive in many space conscious applications. if emi is a concern, such as when sensitive analog circuitry is present, a toroidal inductor such as the coiltronics ctx20-1 is suggested. a special case exists where the v out /v in differential is high, such as a 2v to 12v boost converter. if the required duty cycle for continuous mode operation is higher than the lt1304 can provide, the converter must be designed for discontinuous operation. this means that the inductor current decreases to zero during the switch off time. for a simple step-up (boost) converter, duty cycle can be calculated by the following formula: dc = 1 C [(v in C v sat )/(v out + v d )] where, v in = minimum input voltage v sat = switch saturation voltage (0.3v) v out = output voltage v d = diode forward voltage (0.4v) if the calculated duty cycle exceeds the minimum lt1304 duty cycle of 76%, the converter should be designed for discontinuous mode operation. the inductance must be low enough so that current in the inductor reaches the peak current in a single cycle. inductor value can be calculated by: l = (v in C v sat )(t on /1a) where, t on = minimum on-time of lt1304 (4 m s) one advantage of discontinuous mode operation is that inductor values are usually quite low so very small units can be used. ripple current is higher than with continuous mode designs and efficiency will be somewhat less.
7 lt1304/lt1304-3.3/lt1304-5 table 1 lists inductor suppliers along with appropriate part numbers. table 1. recommended inductors vendor series phone number sumida cd54, cd43 (708) 956-0666 coiltronics ctx20-1 (407) 241-7876 dale lpt4545 (605) 665-9301 coilcraft do3316, do1608, do3308 (708) 639-6400 capacitor selection low esr (equivalent series resistance) capacitors should be used at the output of the lt1304 to minimize output ripple voltage. high quality input bypassing is also re- quired. for surface mount applications avx tps series tantalum capacitors are recommended. these have been specifically designed for switch mode power supplies and have low esr along with high surge current ratings. a 100 m f, 10v avx tps surface mount capacitor typically limits output ripple voltage to 70mv when stepping up from 2v to 5v at a 200ma load. for through hole applica- tions sanyo os-con capacitors offer extremely low esr in a small package size. again, if peak switch current is reduced using the i lim pin, capacitor requirements can be eased and smaller, higher esr units can be used. sug- gested capacitor sources are listed in table 2. table 2. recommended capacitors vendor series type phone number avx tps surface mount (803) 448-9411 sanyo os-con through hole (619) 661-6835 sprague 595d surface mount (603) 225-1961 diode selection best performance is obtained with a schottky rectifier such as the 1n5818. motorola makes the mbrs130l schottky which is slightly better than the 1n5818 and comes in a surface mount package. for lower switch currents, the mbr0530 is recommended. it comes in a very small sod-123 package. multiple 1n4148s in parallel can be used in a pinch, although efficiency will suffer. operatio u i lim function the lt1304s current limit (i lim ) pin can be used for soft start. upon start-up, the lt1304 will draw maximum current (about 1a) from the supply to charge the output capacitor. figure 3 shows v out and v in waveforms as the device is turned on. the high current flow can create ir drops along supply and ground lines or cause the input supply to drop out momentarily. by adding r1 and c1 as shown in figure 4, the switch current is initially limited to well under 1a as detailed in figure 5. current flowing into c1 from r1 and the i lim pin will eventually charge c1 and r1 effectively takes c1 out of the circuit. r1 also provides a discharge path for c1 when shutdown is brought low for turn-off. v out 2v/div i in 500ma/div v shdn 10v/div 1ms/div 1304 f03 figure 3. start-up response. input current rises quickly to 1a. v out reaches 5v in approximately 1ms. output drives 20ma load figure 4. 2-cell to 5v/200ma boost converter takes four external parts. components with dashed lines are for soft start (optional) v in sw gnd i lim sense lbi shdn lb0 lt1304-5 100 m f c1 1 m f 100 m f 2 cells 22 m h* mbrs130l 5v 200ma *sumida cd54-220 1304 f04 shutdown + + + r1 1m
8 lt1304/lt1304-3.3/lt1304-5 operatio u if the full power capability of the lt1304 is not required, peak switch current can be limited by connecting a resistor r lim from the i lim pin to ground. with r lim = 22k, peak switch current is reduced to approximately 500ma. smaller power components can then be used. the graph in figure 6 shows switch current vs r lim resistor value. v shdn 10v/div i in 500ma/div bypass capacitor is required. if the input supply is close to the ic, a 1 m f ceramic capacitor can be used instead. the lt1304 switches current in 1a pulses, so a low impedance supply must be available. if the power source (for example, a 2 aa cell battery) is within 1 or 2 inches of the ic, the battery itself provides bulk capacitance and the 1 m f ce- ramic capacitor acts to smooth voltage spikes at switch turn-on and turn-off. if the power source is far away from the ic, inductance in the power source leads results in high impedance at high frequency. a local high capacitance bypass is then required to restore low impedance at the ic. figure 5. start-up response with 1 m f/1m w components in figure 2 added. input current is more controlled. v out reaches 5v in 6ms. output drives 20ma load layout/input bypassing the lt1304s high speed switching mandates careful attention to pc board layout. suggested component place- ment is shown in figure 7. the input supply must have low impedance at ac and the input capacitor should be placed as indicated in the figure. the value of this capacitor depends on how close the input supply is to the ic. in situations where the input supply is more than a few inches away from the ic, a 47 m f to 100 m f solid tantalum figure 6. peak switch current vs r lim value r lim (k w ) 10 peak current (ma) 1000 900 800 700 600 500 400 100 1000 1304 f06 low-battery detector the lt1304 contains an independent low-battery detector that remains active when the device is shut down. this detector, actually a hysteretic comparator, has an open collector output that can sink up to 500 m a. the compara- tor also operates below the switchers undervoltage lock- out threshold, operating until v in reaches approximately 1.4v. figure 8 illustrates the input/output characteristic of the detector. hysteresis is clearly evident in the figure. figure 7. suggested layout for best performance. input capacitor placement as shown is highly recommended. switch trace (pin 4) copper area is minimized 1304 f07 8 7 6 5 4 3 2 1 lt1304 c out shutdown v out v in + c in + gnd (battery and load return) 1ms/div 1304 f05 v out 2v/div
9 lt1304/lt1304-3.3/lt1304-5 operatio u v lbo 2v/div v lbi 200mv/div 1304 f08 load current (ma) hours (h) 1 100 200 1304 f10 10 1000 100 10 1 figure 10. battery life vs load current. dots specify actual measurements load current (ma) 1 watt hours (wh) 6 5 4 3 2 1 0 10 100 1304 f11 200 figure 11. output watt hours vs load current. note rapid fall-off at higher discharge rates figure 8. low-battery detector transfer function. pull-up r = 22k, v in = 2v, sweep frequency = 10hz v in sw gnd i lim sense shdn lb0 lb1 lt1304-5 c2 100 m f c1 100 m f b1 2 cells l1 22 m h d1 v out 5v 200ma b1 = 2 eveready industrial alkaline aa cells #en91 c1, c2 = avx tpsd107m010r0100 d1 = motorola mbrs130l l1 = sumida cd54-220 1304 f09 + + figure 9. 2-cell to 5v converter used in battery life study battery life how may hours does it work? this is the bottom line question that must be asked of any efficiency study. aa alkaline cells are not perfect power sources. for efficient power transfer, energy must be taken from aa cells at a rate that does not induce excessive loss. aa cells internal impedance, about 0.2 w fresh and 0.5 w end-of-life, results in significant efficiency loss at high discharge rates. figure 10 illustrates battery life vs load current of figure 9s lt1304, 2-cell to 5v dc/dc converter. note the acceler- ated decrease in hours at higher power levels. figure 11 plots total watt hours vs load current. watt hours are determined by the following formula: wh = i load (5v)(h) figure 11s graph varies significantly from electrical effi- ciency plot pictured on the first page of this data sheet. why? as more current is drawn from the battery, voltage drop across the cells internal impedance increases. this causes internal power loss (heating), reducing cell termi- nal voltage. since the regulator input acts as a negative resistance, more current is drawn from the battery as the terminal voltage decreases. this positive feedback action compounds the problem.
10 lt1304/lt1304-3.3/lt1304-5 operatio u load current (ma) 1 electrochemical efficiency (%) 100 90 80 70 60 50 40 30 20 10 0 10 100 1304 f12 200 typical applicatio n s u v in sw shdn gnd lbi lbo i lim fb lt1304 + + 220 m f 100 m f 0.01 m f 47k 2 cells 33 m h** i q ? 10 m a 5v 100ma 1% metal film sumida cd54-330 * ** 1304 ta03 47k 22k 1.21m* 3.83m* mbr0530 200k 2n3906 super burst tm low i q dc/dc converter load current (ma) 40 50 70 60 80 90 efficiency (%) 100 1304 ta04 0.01 0.1 1.0 10 v in = 3v v in = 2v super burst efficiency super burst is a trademark of linear technology corporation. figure 12 shows overall energy conversion efficiency, assuming availability of 6.5wh of battery energy. this efficiency approximates the electrical efficiency at load current levels from 1ma to 10ma, but drops severely at load currents above 10ma (load power above 50mw). the moral of the story is this: if your system needs 5v at more than 40ma to 50ma, consider using a nicd battery (1/10 the internal impedance) instead of a aa cell alkaline battery. figure 12. overall system efficiency including battery efficiency vs load current. internal impedance of alkaline aa cells accounts for rapid drop in efficiency at higher load current
11 lt1304/lt1304-3.3/lt1304-5 typical applicatio n s u 2-cell to 3.3v boost converter v in sw gnd i lim nc sense lt1304-3.3 c2** 100 m f 10v c1** 100 m f 2 cells l1* 22 m h mbrs130l 3.3v 300ma *sumida cd54-220 **avx tpsd107m010r0100 1304 ta05 shutdown shdn + + 2-cell to 3.3v converter efficiency load current (ma) 90 80 70 60 50 40 30 efficiency (%) 1304 ta06 0.1 1 10 1000 100 v in = 3.3v v in = 2.5v v in = 2.5v load current (ma) 90 80 70 60 50 40 30 efficiency (%) 1304 ta06 0.1 1 10 1000 100 v in = 3.3v v in = 2.5v v in = 1.8v 3.3v sepic (step-up/step-down converter) load current (ma) 1 efficiency (%) 10 100 500 1304 ta08 80 75 70 65 60 55 50 v in = 4.5v v in = 3.5v v in = 2.5v 3.3v sepic efficiency 5v sepic (step-up/step-down converter) 5v sepic efficiency load current (ma) 1 efficiency (%) 10 100 500 1304 ta10 80 75 70 65 60 55 50 v in = 6v v in = 5v v in = 4v v in = 3v v in i lim sw gnd nc sense v in 3v to 8v lt1304-5 100 m f ?? 10v 47 m f ? 16v c1** 1 m f l1a* mbrs130l 2 1 5v 200ma * coiltronics ctx20-1 ** tokin 1e105zy5u-c103-f ? avx tpsd476m016r0150 ?? avx tpsd107m010r0100 1304 ta09 shutdown shdn + l1b* 4 3 + v in i lim sw gnd nc sense v in 2.5v to 8v lt1304-3.3 c3 ?? 100 m f 10v c2 ? 47 m f 16v c1** 1 m f l1a* mbrs130l 2 1 3.3v 300ma * coiltronics ctx20-1 ** tokin 1e105zy5u-c103-f ? avx tpsd476m016r0150 ?? avx tpsd107m010r0100 1304 ta07 shutdown shdn + l1b* 4 3 +
12 lt1304/lt1304-3.3/lt1304-5 typical applicatio n s u single li-ion cell to 5v converter with load disconnect at v in < 2.7v v in sw gnd fb 5v lt1304 47 m f** 16v 47 m f** l1* 22 m h d1 ? 1.07m 1% 12v 200ma 124k 1% * sumida cd54-220 ** avx tpsd476m016r0150 ? motorola mbrs130l 1304 ta11 shutdown shdn + + 5v to 12v dc/dc converter 5v to 12v converter efficiency load current (ma) 1 efficiency (%) 10 100 300 1304 ta12 90 85 80 75 70 65 + 1304 ta13 LT1304CS8-5 22 m h** mbrs130lt3 (5v) (2.7v to 4.2v) sw gnd sense nc 220k * primary li-ion battery protection must be provided by an independent circuit ** sumida cd54-220 ? avx tpsd107m010r0100 lbo v in i lim lbi 100 m f ? 10v shdn ltc1477 v out v in2 gnd v out v in1 v ins nc nc v in3 en 562k 1% 432k 1% single li-ion cell* + 100 m f 16v + 1 m f 5v
13 lt1304/lt1304-3.3/lt1304-5 typical applicatio n s u negative lcd bias generator electroluminescent panel driver with 200hz oscillator v in sw gnd fb 22k i lim lt1304 + + 1m 1% ** ** ** 110k 1% 90.9k 1% voltage adjust 1khz pwm input 0v to 5v 1.69m 1% 1 m f ceramic 47 m f 3.3 m f 10 m f 35v 1000pf 2 cells l1* 10 m h ? out 14v to ?2v 1ma to 10ma * sumida cd43-100 ** motorola mbr0530 1304 ta14 + efficiency = 70% to 75% at i load 3 2ma danger! high voltage v in sw gnd 200hz nc fb 3.3k i lim lbi lbo 34 16 lt1304 51k 22k 22k 22k 1/2 baw56 fmmt458 mbr0530 50k intensity adjust 10m (3.3m 3) 1 m f 200v mur160 600v 1nf 0.01 m f 47 m f el panel c panel 20nf 1:12* * dale lpe3325-a205 transformer measures 6.5mm 8.2mm 5.2mm (h) (605) 665-9301 1304 ta15 shdn 22k 22k v in 2v to 7v 5v = operate 0v = shutdown 2n3906 75k 1/2 baw56 +
14 lt1304/lt1304-3.3/lt1304-5 typical applicatio n s u 2- to 4-cell to 5v converter with output disconnect v in v in 2v to 6v sw gnd i lim nc sense lt1304-5 22 m f* 47 m f* l1** 22 m h mbrs130l ztx788b 2k *avx tps series tantalum or sanyo os-con **sumida cd54-220 1304 ta17 shutdown shdn + + 220 m f* 5v 100ma + v in sw gnd nc fb i lim 34 16 lt1304 mbr0530 0.01 m f 0.01 m f 0.01 m f 0.01 m f 47 m f t1* 1304 ta16 shdn shutdown 0.1 m f v in 2v to 6v + r2 620k r1** 500m v out 1kv 250 m a v out = 1.24v 1+ r1 r2 () 0.01 m f 0.01 m f 0.01 m f 0.01 m f 0.01 m f * dale lpe3325-a205 transformer measures 6.5mm 8.2mm 5.2mm (h) (605) 665-9301 ** irc cgx-1/2 all 0.01 m f capacitors 250wvdc bas21 or mur130 danger! high voltage 2- to 4-cell to 1kv step-up converter
15 lt1304/lt1304-3.3/lt1304-5 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 circuits as described herein will not infringe on existing patent rights. typical applicatio n s u 2-cell to 5v converter with auxiliary 10v output 2-cell to 5v converter with auxiliary C 5v output v in sw gnd i lim nc sense lt1304-5 100 m f 2 cells l1* 22 m h mbrs130l mbr0530 mbr0530 *sumida cd54-220 1304 ta19 shutdown shdn + 100 m f 10 m f 1 m f ceramic 5v 150ma 5v 20ma + + v in sw gnd i lim nc sense lt1304-5 100 m f 1 m f ceramic 2 cells l1* 22 m h mbrs130l mbr0530 mbr0530 *sumida cd54-220 1304 ta18 shutdown shdn + 100 m f 5v 150ma 10v 20ma + 10 m f +
16 lt1304/lt1304-3.3/lt1304-5 lt/gp 1195 10k ? printed in usa ? linear technology corporation 1995 linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 l fax : (408) 434-0507 l telex : 499-3977 package descriptio n u dimension in inches (millimeter) unless otherwise noted. s8 package 8-lead plastic small outline (narrow 0.150) (ltc dwg # 05-08-1610) 1 2 3 4 0.150 ?0.157** (3.810 ?3.988) 8 7 6 5 0.189 ?0.197* (4.801 ?5.004) 0.228 ?0.244 (5.791 ?6.197) 0.016 ?0.050 0.406 ?1.270 0.010 ?0.020 (0.254 ?0.508) 45 0 ?8 typ 0.008 ?0.010 (0.203 ?0.254) so8 0695 0.053 ?0.069 (1.346 ?1.752) 0.014 ?0.019 (0.355 ?0.483) 0.004 ?0.010 (0.101 ?0.254) 0.050 (1.270) bsc dimension does not include mold flash. mold flash shall not exceed 0.006" (0.152mm) per side dimension does not include interlead flash. interlead flash shall not exceed 0.010" (0.254mm) per side * ** part number description comments ltc ? 1163 triple high side driver for 2-cell inputs 1.8v minimum input, drives n-channel mosfets lt1239 backup battery management system easy-to-use, fail-safe backup protection lt1301 fixed 5v/12v step-up micropower dc/dc converter 12v/200ma from 5v, 120 m a i q , 88% efficiency lt1302 high output current micropower dc/dc converter 5v/600ma from 2v, 2a internal switch, 200 m a i q lt1303 micropower dc/dc converter low-battery detector inactive in shutdown ltc1477 protected switch ultralow r ds(on) switch: 0.07 w lt1521 300ma, 12 m a i q low dropout regulator 500mv dropout at full load related parts

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