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lt3007 series 1 3007f for more information www.linear.com/lt3007 typical application features applications description 3 a i q , 20ma, 45v low dropout fault tolerant linear regulators the lt ? 3007 series are micropower, low dropout voltage (ldo) linear regulators. the devices supply 20ma output current with a dropout voltage of 300mv. no-load quies - cent current is 3a. ground pin current remains at less than 5% of output current as load increases. in shutdown, quiescent current is less than 1a. the lt3007 regulators optimize stability and transient response with low esr ceramic capacitors, requiring a minimum of only 2.2f. the regulators do not require the addition of esr as is common with other regulators. internal protection circuitry includes current limiting, thermal limiting, reverse-battery protection and reverse- current protection. the lt3007 series are ideal for applications that require moderate output drive capability coupled with ultralow standby power consumption. the device is available in fxed output voltages of 1.2v, 1.5v, 1.8v, 2.5v, 3.3v and 5v, and an adjustable version with an output voltage range of 0.6v to 44.5v. the lt3007 is available in the thermally enhanced 8-lead tsot-23 package. 3.3v, 20ma supply with shutdown n fmea fault tolerant: output stays at or below regulation voltage during adjacent pin short or if a pin is left floating n ultralow quiescent current: 3a n input voltage range: 2.0v to 45v n output current: 20ma n dropout voltage: 300mv n adjustable output (v adj = v out(min) = 600mv) n fixed output voltages: 1.2v, 1.5v, 1.8v, 2.5v, 3.3v, 5v n output tolerance: 2% over load, line and temperature n stable with low esr, ceramic output capacitors (2.2f minimum) n shutdown current: <1a n current limit protection n reverse-battery protection n thermal limit protection n tsot-23 package n automotive n low current battery-powered systems n keep-alive power supplies n remote monitoring n utility meters n low power industrial applications dropout voltage/quiescent current l , lt, ltc, ltm, linear technology and the linear logo are registered and thinsot is a trademark of linear technology corporation. all other trademarks are the property of their respective owners. temperature (c) dropout voltage (mv) quiescent current (a) 400 3007 ta01b 200 100 50 0 500 300 250 150 5 350 2 3 1 0 6 450 4 ?50 ?25 0 25 50 75 100 125 150 i load = 20ma dropout voltage i q in shdn 2.2f 3007 ta01a out sense v in 3.8v to 45v gnd lt3007-3.3 v out 3.3v 20ma 1f
lt3007 series 2 3007f for more information www.linear.com/lt3007 pin configuration absolute maximum ratings in pin voltage ......................................................... 50v out pin voltage ...................................................... 50v input-to-output differential voltage ........................ 50v adj pin voltage ...................................................... 50v sense pin voltage .................................................. 50v shdn pin voltage (note 8) ..................................... 50v output short-circuit duration .......................... indefnite operating junction temperature range (notes 2, 3) e, i grade ........................................... C40c to 125c storage temperature range ................... C65c to 150c lead temperature: soldering, 10 sec .................... 300c (note 1) shdn 1 gnd 2 gnd 3 gnd 4 8 adj/sense** 7 out 6 nc 5 in top view ts8 package 8-lead plastic tsot-23 t jmax = 125c, ja = 65c/w to 85c/w* order information lead free finish tape and reel part marking* package description temperature range lt3007ets8#pbf lt3007ets8#trpbf ltgjw 8-lead plastic tsot-23 C40c to 125c lt3007its8#pbf lt3007its8#trpbf ltgjw 8-lead plastic tsot-23 C40c to 125c lt3007ets8-1.2#pbf lt3007ets8-1.2#trpbf ltgkb 8-lead plastic tsot-23 C40c to 125c lt3007its8-1.2#pbf lt3007its8-1.2#trpbf ltgkb 8-lead plastic tsot-23 C40c to 125c lt3007ets8-1.5#pbf lt3007ets8-1.5#trpbf ltgkd 8-lead plastic tsot-23 C40c to 125c lt3007its8-1.5#pbf lt3007its8-1.5#trpbf ltgkd 8-lead plastic tsot-23 C40c to 125c lt3007ets8-1.8#pbf lt3007ets8-1.8#trpbf ltgjz 8-lead plastic tsot-23 C40c to 125c lt3007its8-1.8#pbf lt3007its8-1.8#trpbf ltgjz 8-lead plastic tsot-23 C40c to 125c lt3007ets8-2.5#pbf lt3007ets8-2.5#trpbf ltgjx 8-lead plastic tsot-23 C40c to 125c lt3007its8-2.5#pbf lt3007its8-2.5#trpbf ltgjx 8-lead plastic tsot-23 C40c to 125c lt3007ets8-3.3#pbf lt3007ets8-3.3#trpbf ltgkc 8-lead plastic tsot-23 C40c to 125c lt3007its8-3.3#pbf lt3007its8-3.3#trpbf ltgkc 8-lead plastic tsot-23 C40c to 125c lt3007ets8-5#pbf lt3007ets8-5#trpbf ltgjy 8-lead plastic tsot-23 C40c to 125c lt3007its8-5#pbf lt3007its8-5#trpbf ltgjy 8-lead plastic tsot-23 C40c to 125c consult ltc marketing for parts specifed with wider operating temperature ranges. *the temperature grade is identifed by a label on the shipping container. for more information on lead free part marking, go to: http://www.linear.com/leadfree/ for more information on tape and reel specifcations, go to: http://www.linear.com/tapeandreel/ * see the applications information section. ** sense for fixed voltage output versions.
lt3007 series 3 3007f for more information www.linear.com/lt3007 electrical characteristics the l denotes the specifcations which apply over the full operating temperature range, otherwise specifcations are at t j = 25c. (note 2) parameter conditions min typ max units operating voltage l 2 45 v regulated output voltage lt3007-1.2: v in = 2v, i load = 100a 2v < v in < 45v, 1a < i load < 20ma l 1.188 1.176 1.2 1.2 1.212 1.224 v v lt3007-1.5: v in = 2.05v, i load = 100a 2.05v < v in < 45v, 1a < i load < 20ma l 1.485 1.47 1.5 1.5 1.515 1.53 v v lt3007-1.8: v in = 2.35v, i load = 100a 2.35v < v in < 45v, 1a < i load < 20ma l 1.782 1.764 1.8 1.8 1.818 1.836 v v lt3007-2.5: v in = 3.05v, i load = 100a 3.05v < v in < 45v, 1a < i load < 20ma l 2.475 2.45 2.5 2.5 2.525 2.55 v v lt3007-3.3: v in = 3.85v, i load = 100a 3.85v < v in < 45v, 1a < i load < 20ma l 3.267 3.234 3.3 3.3 3.333 3.366 v v lt3007-5: v in = 5.55v, i load = 100a 5.55v < v in < 45v, 1a < i load < 20ma l 4.95 4.9 5 5 5.05 5.1 v v adj pin voltage (notes 3, 4) v in = 2v, i load = 100a 2v < v in < 45v, 1a < i load < 20ma l 594 588 600 600 606 612 mv mv line regulation (note 3) lt3007-1.2: ?v in = 2v to 45v, i load = 1ma lt3007-1.5: ?v in = 2.05v to 45v, i load = 1ma lt3007-1.8: ?v in = 2.35v to 45v, i load = 1ma lt3007-2.5: ?v in = 3.05v to 45v, i load = 1ma lt3007-3.3: ?v in = 3.85v to 45v, i load = 1ma lt3007-5: ?v in = 5.55v to 45v, i load = 1ma lt3007: ?v in = 2v to 45v, i load = 1ma l l l l l l l 1.2 1.5 1.8 2.5 3.3 5 0.6 6 7.5 9 12.5 16.5 25 3 mv mv mv mv mv mv mv load regulation (note 3) lt3007-1.2: v in = 2v, i load = 1a to 10ma v in = 2v, i load = 1a to 20ma l l 0.8 1 4 10 mv mv lt3007-1.5: v in = 2.05v, i load = 1a to 10ma v in = 2.05v, i load = 1a to 20ma l l 1 1.3 5 13 mv mv lt3007-1.8: v in = 2.35v, i load = 1a to 10ma v in = 2.35v, i load = 1a to 20ma l l 1.2 1.5 6 15 mv mv lt3007-2.5: v in = 3.05v, i load = 1a to 10ma v in = 3.05v, i load = 1a to 20ma l l 1.7 2.1 8.3 21 mv mv lt3007-3.3: v in = 3.85v, i load = 1a to 10ma v in = 3.85v, i load = 1a to 20ma l l 2.2 2.8 11 28 mv mv lt3007-5: v in = 5.55v, i load = 1a to 10ma v in = 5.55v, i load = 1a to 20ma l l 3.4 4.2 17 42 mv mv lt3007: v in = 2v, i load = 1a to 10ma v in = 2v, i load = 1a to 20ma l l 0.4 0.5 2 5 mv mv dropout voltage v in = v out(nominal) (notes 5, 6) i load = 100a i load = 100a l 115 180 250 mv mv i load = 1ma i load = 1ma l 170 250 350 mv mv i load = 10ma i load = 10ma l 270 340 470 mv mv i load = 20ma i load = 20ma l 300 365 500 mv mv quiescent current (notes 6, 7) i load = 0a i load = 0a l 3 6 a a
lt3007 series 4 3007f for more information www.linear.com/lt3007 parameter conditions min typ max units gnd pin current v in = v out(nominal) + 0.5v (notes 6, 7) i load = 0a i load = 100a i load = 1ma i load = 10ma i load = 20ma l l l l l 3 6 21 160 350 6 12 50 500 1200 a a a a a output voltage noise (note 9) c out = 2.2f, i load = 20ma, bw = 10hz to 100khz 92 v rms adj pin bias current C10 0.4 10 na shutdown threshold v out = off to on v out = on to off l l 0.25 0.67 0.61 1.5 v v shdn pin current v shdn = 0v, v in = 45v v shdn = 45v, v in = 45v l l 0.65 1 2 a a quiescent current in shutdown v in = 6v, v shdn = 0v l <1 a ripple rejection (note 3) v in C v out = 2v, v ripple = 0.5v p-p , f ripple = 120hz, i load = 20ma lt3007 lt3007-1.2 lt3007-1.5 lt3007-1.8 lt3007-2.5 lt3007-3.3 lt3007-5 58 54 53 52 49 47 42 70 66 65 64 61 59 54 db db db db db db db current limit v in = 45v, v out = 0 v in = v out(nominal) + 1v, ?v out = C 5% l 22 75 ma ma input reverse-leakage current v in = C45v, v out = 0 l 1 30 a reverse-output current v out = 1.2v, v in = 0 0.6 10 a electrical characteristics the l denotes the specifcations which apply over the full operating temperature range, otherwise specifcations are at t j = 25c. (note 2) 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 lt3007 regulators are tested and specifed under pulse load conditions such that t j @ t a . the lt3007e is guaranteed to meet performance specifcations from 0c to 125c operating junction temperature. specifcations over the C40c to 125c operating junction temperature range are assured by design, characterization and correlation with statistical process controls. the lt3007i is guaranteed over the full C 40 c to 125c operating junction temperature range. note 3: the lt3007 adjustable version is tested and specifed for these conditions with the adj pin connected to the out pin. note 4: operating conditions are limited by maximum junction temperature. the regulated output voltage specifcation will not apply for all possible combinations of input voltage and output current. when operating at the maximum input voltage, the output current range must be limited. when operating at the maximum output current, the input voltage must be limited. note 5: dropout voltage is the minimum input to output voltage differential needed to maintain regulation at a specifed output current. in dropout, the output voltage equals (v in C v dropout ). for the lt3007-1.2 and lt3007 - 1.5, dropout voltage will be limited by the minimum input voltage. note 6: to satisfy minimum input voltage requirements, the lt3007 adjustable version is tested and specifed for these conditions with an external resistor divider (61.9k bottom, 280k top) which sets v out to 3.3v. the external resistor divider adds 9.69a of dc load on the output. this external current is not factored into gnd pin current. note 7: gnd pin current is tested with v in = v out(nominal) + 0.55v and a current source load. gnd pin current will increase in dropout. for the fxed output voltage versions, an internal resistor divider will add about 1a to the gnd pin current. see the gnd pin current curves in the typical performance characteristics section. note 8: the shdn pin can be driven below gnd only when tied to the in pin directly or through a pull-up resistor. if the shdn pin is driven below gnd by more than C0.3v while in is powered, the output will turn on. note 9: output noise is listed for the adjustable version with the adj pin connected to the out pin. see the rms output noise vs load current curve in the typical performance characteristics section.
lt3007 series 5 3007f for more information www.linear.com/lt3007 dropout voltage dropout voltage minimum input voltage typical performance characteristics t a = 25c, unless otherwise noted. output voltage lt3007-1.8 output voltage lt3007-3.3 output voltage lt3007-2.5 adj pin voltage output voltage lt3007-1.2 output voltage lt3007-1.5 output current (ma) 0 0 dropout voltage (mv) 50 150 200 250 10 12 14 20 450 100 2 4 6 8 16 18 300 350 400 3007 g01 t j = 125c t j = 25c temperature (c) 0 dropout voltage (mv) 50 150 200 250 450 100 300 350 400 3007 g02 20ma 10ma 1ma 100a ?50 ?25 0 25 50 75 100 125 150 0 0.6 0.4 0.2 0.8 1 1.2 1.4 1.6 1.8 2.0 temperature (c) minimum input voltage (v) 3007 g03 i load = 20ma ?50 ?25 0 25 50 75 100 125 150 temperature (c) adj pin voltage (v) 3007 g04 0.596 0.608 0.610 0.612 0.590 0.592 0.604 0.600 0.594 0.606 0.588 0.602 0.598 ?50 ?25 0 25 50 75 100 125 150 i load = 100a temperature (c) output voltage (v) 3007 g05 1.192 1.216 1.220 1.224 1.180 1.184 1.208 1.200 1.188 1.212 1.176 1.204 1.196 ?50 ?25 0 25 50 75 100 125 150 i load = 100a temperature (c) output voltage (v) 3007 g06 1.490 1.520 1.525 1.530 1.475 1.480 1.510 1.500 1.485 1.515 1.470 1.505 1.495 ?50 ?25 0 25 50 75 100 125 150 i load = 100a temperature (c) output voltage (v) 3007 g07 1.788 1.824 1.830 1.836 1.770 1.776 1.812 1.800 1.782 1.816 1.764 1.806 1.794 ?50 ?25 0 25 50 75 100 125 150 i load = 100a temperature (c) output voltage (v) 3007 g08 2.480 2.540 2.550 2.460 2.520 2.500 2.470 2.530 2.450 2.510 2.490 ?50 ?25 0 25 50 75 100 125 150 i load = 100a temperature (c) output voltage (v) 3007 g09 3.267 3.278 3.355 3.366 3.245 3.322 3.300 3.256 3.333 3.344 3.234 3.311 3.289 ?50 ?25 0 25 50 75 100 125 150 i load = 100a
lt3007 series 6 3007f for more information www.linear.com/lt3007 typical performance characteristics t a = 25c, unless otherwise noted. gnd pin current lt3007-1.2 gnd pin current lt3007-1.5 gnd pin current lt3007-1.8 gnd pin current lt3007-2.5 gnd pin current lt3007-3.3 quiescent current output voltage lt3007-5 adj pin bias current adjustable quiescent current temperature (c) output voltage (v) 3007 g10 4.950 5.075 5.100 5.025 5.000 4.925 5.050 4.900 4.975 ?50 ?25 0 25 50 75 100 125 150 i load = 100a temperature (c) adj pin bias current (na) 3007 g11 ?4 8 10 ?10 ?8 4 0 ?6 6 2 ?2 ?50 ?25 0 25 50 75 100 125 150 temperature (c) quiescent current (a) 3007 g12 2 5 6 1 4 3 0 ?50 ?25 0 25 50 75 100 125 150 input voltage (v) quiescent current (a) 3007 g13 12 30 3 6 18 21 9 0 27 24 15 0 21 43 5 6 87 9 10 lt3007-1.2 lt3007-1.5 lt3007-1.8 lt3007-2.5 lt3007-3.3 lt3007-5 0 200 450 500 2 4 6 100 350 150 400 50 0 300 250 1 3 8 10 5 7 9 3007 g14 input voltage (v) gnd pin current (a) r l = 60, i l = 20ma r l = 120, i l = 10ma r l = 1.2k, i l = 1ma r l = 12k, i l = 100a 0 200 450 500 2 4 6 100 350 150 400 50 0 300 250 1 3 8 10 5 7 9 3007 g15 input voltage (v) gnd pin current (a) r l = 75, i l = 20ma r l = 150, i l = 10ma r l = 1.5k, i l = 1ma r l = 15k, i l = 100a 0 200 450 500 2 4 6 100 350 150 400 50 0 300 250 1 3 8 10 5 7 9 3007 g16 input voltage (v) gnd pin current (a) r l = 90, i l = 20ma r l = 180, i l = 10ma r l = 1.8k, i l = 1ma r l = 18k, i l = 100a 0 200 450 500 2 4 6 100 350 150 400 50 0 300 250 1 3 8 10 5 7 9 3007 g17 input voltage (v) gnd pin current (a) r l = 125, i l = 20ma r l = 250, i l = 10ma r l = 2.5k, i l = 1ma r l = 25k, i l = 100a 0 200 450 500 2 4 6 100 350 150 400 50 0 300 250 1 3 8 10 5 7 9 3007 g18 input voltage (v) gnd pin current (a) r l = 165, i l = 20ma r l = 330, i l = 10ma r l = 3.3k, i l = 1ma r l = 33k, i l = 100a
lt3007 series 7 3007f for more information www.linear.com/lt3007 typical performance characteristics t a = 25c, unless otherwise noted. shdn pin input current shdn pin input current current limit reverse-output current input ripple rejection input ripple rejection gnd pin current lt3007-5 gnd pin current vs i load shdn pin thresholds 0 200 450 500 2 4 6 100 350 150 400 50 0 300 250 1 3 8 10 5 7 9 3007 g19 input voltage (v) gnd pin current (a) r l = 250, i l = 20ma r l = 500, i l = 10ma r l = 5k, i l = 1ma r l = 50k, i l = 100a 1 10 100 1000 load (ma) gnd current (a) 3007 g20 0.001 0.01 0.1 1 10 100 v in = 3.8v v out = 3.3v ?50 0.6 1.4 1.5 0 75 0.3 1.2 1.1 0.4 0.5 1.3 0.1 0.2 0 1 0.9 0.8 0.7 ?25 25 150 50 100 125 3007 g21 temperature (c) shdn pin threshold (v) off to on on to off 0 0.8 1.8 2.0 10 20 30 0.4 1.4 0.6 1.6 0.2 0 1.2 1 5 15 45 25 35 40 3007 g22 shdn pin voltage (v) shdn pin input current (a) ?50 0.8 2.0 0 25 75 0.4 1.6 0.6 1.8 0.2 0 1.4 1 1.2 ?25 100 150 50 125 3007 g23 temperature (c) shdn pin input current (a) v shdn = 45v 40 100 20 70 80 30 90 10 0 60 50 3007 g24 temperature (c) current limit (ma) ?50 0 75 ?25 25 150 50 100 125 v in = 2v v in = 45v 3007 g25 temperature (c) reverse output current (a) 20 50 10 35 40 15 45 5 0 30 25 ?50 0 75 ?25 25 150 50 100 125 out adj out = adj = 1.2v in = shdn = gnd 0 10 30 20 40 50 70 60 90 80 frequency (hz) 3007 g26 10 100 1000 100000 10000 1000000 input ripple rejection (db) v in = 2.1v + 50mv rms v out = 600mv i load = 20ma c out = 10f c out = 2.2f input ripple rejection (db) 60 80 30 40 50 70 20 10 0 3007 g27 temperature (c) ?50 0 75 ?25 25 150 50 100 125 v in = v out (nominal) + 2v + 0.5v p-p ripple at f = 120hz i load = 20ma
lt3007 series 8 3007f for more information www.linear.com/lt3007 typical performance characteristics t a = 25c, unless otherwise noted. transient response transient response transient response (load dump) load regulation output noise spectral density rms output noise vs load current 0 0.5 2.0 2.5 1.5 1.0 3.0 3.5 4.0 4.5 5.0 load regulation (mv) 3007 g28 temperature (c) ?50 0 75 ?25 25 150 50 100 125 ?i l = 1a to 20ma v out = 600mv v in = 2v frequency (hz) 0.1 output noise spectral density (vhz) 1 100 10 3007 g29 10 100 1k 10k 100k 5v 3.3v 2.5v 1.8v 1.5v 1v 0.6v c out = 2.2f i load = 20ma i load (ma) 0.001 350 450 400 500 10 3007 g30 300 250 0.01 0.1 1 100 200 100 150 50 0 output noise (v rms ) 3.3v 2.5v 1.8v 1.2v 0.6v 1.5v 5v c out = 10f 500s/div v out 50mv/div i out 20ma/div 3007 g31 i out = 1ma to 20ma v in = 5.5v v out = 5v c out = 2.2f 500s/div v out 50mv/div i out 20ma/div 3007 g32 i out = 1ma to 20ma v in = 5.5v v out = 5v c out = 10f 1ms/div v out 50mv/div 45v 12v v in 10v/div 3007 g33 v out = 5v i out = 20ma c out = 4.7f
lt3007 series 9 3007f for more information www.linear.com/lt3007 pin functions shdn (pin 1): shutdown. pulling the shdn pin low puts the lt3007 into a low power state and turns the output off. if unused, tie the shdn pin to v in . the lt3007 does not function if the shdn pin is not connected. the shdn pin cannot be driven below gnd unless tied to the in pin. if the shdn pin is driven below gnd while in is powered, the output will turn on. shdn pin logic cannot be referenced to a negative rail. gnd (pins 2, 3, 4): ground. connect the bottom of the resistor divider that sets output voltage directly to gnd for the best regulation. in (pin 5): input. the in pin supplies power to the device. the lt3007 requires a bypass capacitor at in if the device is more than six inches away from the main input flter capacitor. in general, the output impedance of a battery rises with frequency, so it is advisable to include a bypass capacitor in battery-powered circuits. a bypass capacitor in the range of 0.1f to 10f will suffce. the lt3007 withstands reverse voltages on the in pin with respect to ground and the out pin. in the case of a reversed input, which occurs with a battery plugged in backwards, the lt3007 acts as if a blocking diode is in series with its input. no reverse current fows into the lt3007 and no reverse voltage appears at the load. the device protects both itself and the load. nc (pin 6): no connect. pin 6 is an nc pin in the tsot-23 package. this pin is not tied to any internal circuitry. ltc recommends that the nc pin be foated for fault tolerant operation. out (pin 7): output. this pin supplies power to the load. use a minimum output capacitor of 2.2f to prevent os - cillations. large load transient applications require larger output capacitors to limit peak voltage transients. see the applications information section for more information on output capacitance and reverse-output characteristics. adj (pin 8): adjust. this pin is the error amplifers inverting terminal. its 400pa typical input bias current fows out of the pin (see curve of adj pin bias current vs temperature in the typical performance characteristics section). the adj pin voltage is 600mv referenced to gnd and the output voltage range is 600mv to 44.5v. sense (pin 8): sense. for fxed voltage versions of the lt3007 (lt3007-1.2, lt3007-1.5, lt3007-1.8, lt3007-2.5, lt3007-3.3, lt3007-5), the sense pin is the input to the error amplifer. optimum regulation is obtained at the point where the sense pin is connected to the out pin of the regulator. in critical applications, small voltage drops are caused by the resistance (rp) of pc traces between the regulator and the load. these may be eliminated by con - necting the sense pin to the output at the load as shown in figure 1 (kelvin sense connection). note that the volt - age drop across the external pc traces add to the dropout voltage of the regulator. the sense pin bias current is 1a at the nominal rated output voltage. the sense pin can be pulled below ground (as in a dual supply system where the regulator load is returned to a negative supply) and still allow the device to start and operate. figure 1. kelvin sense connection in shdn 3007 f01 r p out v in sense gnd lt3007 r p + + load
lt3007 series 10 3007f for more information www.linear.com/lt3007 applications information the lt3007 is a low dropout linear regulator with ultra- low quiescent current and shutdown. quiescent current is extremely low at 3a and drops well below 1a in shut - down. the device supplies up to 20ma of output current. dropout voltage at 20ma is typically 300mv. the lt3007 incorporates several protection features, making it ideal for use in battery-powered systems. the device protects itself against both reverse-input and reverse-output voltages. in battery backup applications, where a backup battery holds up the output when the input is pulled to ground, the lt3007 acts as if a blocking diode is in series with its output and prevents reverse current fow. in applications where the regulator load returns to a negative supply, the output can be pulled below ground by as much as 50v without affecting start-up or normal operation. adjustable operation the lt3007 has an output voltage range of 0.6v to 44.5v. figure 2 shows that output voltage is set by the ratio of two external resistors. the ic regulates the output to maintain the adj pin voltage at 600mv referenced to ground. the current in r1 equals 600mv/r1 and the current in r2 is the current in r1 minus the adj pin bias current. the adj pin bias current, typically 400pa at 25c, fows out of the pin. calculate the output voltage using the formula in figure 2. an r1 value of 619k sets the divider current to 0.97a. do not make r1s value any greater than 619k to minimize output voltage errors due to the adj pin bias current and to insure stability under minimum load condi - tions. in shutdown, the output turns off and the divider current is zero. curves of adj pin voltage vs temperature and adj pin bias current vs temperature appear in the typical performance characteristics. specifcations for output voltages greater than 0.6v are proportional to the ratio of the desired output voltage to 0.6v: v out /0.6v. for example, load regulation for an output current change of 100a to 20ma is C0.5mv typical at v out = 0.6v. at v out = 5v, load regulation is: 5v 0.6v ? ( ? 0.5mv) = ? 4.17mv table 1 shows resistor divider values for some com- mon output voltages with a resistor divider current of about 1a. figure 2. adjustable operation table 1. output voltage resistor divider values v out r1 r2 1v 604k 402k 1.2v 590k 590k 1.5v 590k 887k 1.8v 590k 1.18m 2.5v 590k 1.87m 3v 590k 2.37m 3.3v 619k 2.8m 5v 590k 4.32m in shdn r2 r1 3007 f02 out v in v out = 600mv ? (1 + r2/r1) C (i adj ? r2) v adj = 600mv i adj = 0.4na at 25c output range = 0.6v to 44.5v adj gnd lt3007 v out
lt3007 series 11 3007f for more information www.linear.com/lt3007 applications information figure 3. ceramic capacitor dc bias characteristics figure 4. ceramic capacitor temperature characteristics because the adj pin is relatively high impedance (de - pending on the resistor divider used), stray capacitances at this pin should be minimized. special attention should be given to any stray capacitances that can couple ex- ternal signals onto the adj pin, producing undesirable output transients or ripple. extra care should be taken in assembly when using high valued resistors. small amounts of board contamination can lead to signifcant shifts in output voltage. appropriate post-assembly board cleaning measures should be implemented to prevent board contamination. if the board is to be subjected to humidity cycling or if board cleaning measures cannot be guaranteed, consideration should be given to using resistors an order of magnitude smaller than in table 1 to prevent contamination from causing unwanted shifts in the output voltage. a fxed voltage option in the lt3007 series does not need these special considerations. output capacitance and transient response the lt3007 is stable with a wide range of output capaci - tors. the esr of the output capacitor affects stability, most notably with small capacitors. use a minimum output capacitor of 2.2f with an esr of 3 or less to prevent oscillations. the lt3007 is a micropower device and output load transient response is a function of output capacitance. larger values of output capacitance decrease the peak deviations and provide improved transient response for larger load current changes. give extra consideration to the use of ceramic capacitors. manufacturers make ceramic capacitors with a variety of dielectrics, each with different behavior across temperature and applied voltage. the most common dielectrics are specifed with eia temperature characteristic codes of z5u, y5v, x5r and x7r. the z5u and y5v dielectrics provide high c-v products in a small package at low cost, but exhibit strong voltage and temperature coeffcients as shown in figures 3 and 4. when used with a 5v regulator, a 16v 10f y5v capacitor can exhibit an effective value as low as 1f to 2f for the dc bias voltage applied and over the operating temperature range. the x5r and x7r dielectrics yield more stable characteristics and are more suitable for use as the output capacitor. the x7r type has better stability across temperature, while the x5r is less expensive and is available in higher values. one must still exercise care when using x5r and x7r capacitors; the x5r and x7r codes only specify operating temperature range and maximum capacitance change over temperature. capacitance change due to dc bias with x5r and x7r capacitors is better than y5v and z5u capacitors, but can still be signifcant enough to drop capacitor values below appropriate levels. capacitor dc bias characteristics tend to improve as component case size increases, but expected capacitance at operating voltage should be verifed. voltage and temperature coeffcients are not the only sources of problems. some ceramic capacitors have a piezoelectric response. a piezoelectric device generates dc bias voltage (v) change in value (%) 3007 f03 20 0 ?20 ?40 ?60 ?80 ?100 0 4 8 10 2 6 12 14 x5r y5v 16 both capacitors are 16v, 1210 case size, 10f temperature (c) ?50 40 20 0 ?20 ?40 ?60 ?80 ?100 25 75 3007 f04 ?25 0 50 100 125 y5v change in value (%) x5r both capacitors are 16v, 1210 case size, 10f
lt3007 series 12 3007f for more information www.linear.com/lt3007 applications information figure 5. noise resulting from tapping on a ceramic capacitor accomplished by using the heat spreading capabilities of the pc board and its copper traces. copper board stiffen - ers and plated through-holes can also be used to spread the heat generated by power devices. the following tables list thermal resistance for several different board sizes and copper areas. all measurements were taken in still air on 3/32" fr-4 two-layer boards with one ounce copper. pcb layers, copper weight, board layout and thermal vias affect the resultant thermal resistance. although table?2 provides thermal resistance numbers for 2-layer boards with 1 ounce copper, modern multilayer pcbs provide bet - ter performance than found in these tables. for example, a 4-layer, 1 ounce copper pcb board with three thermal vias from the three fused tsot-23 gnd pins to inner layer gnd planes achieves 45c/w thermal resistance. this is approximately a 30% improvement over the lowest numbers shown in table 2. voltage across its terminals due to mechanical stress, similar to the way a piezoelectric accelerometer or micro- phone works. for a ceramic capacitor, the stress can be induced by vibrations in the system or thermal transients . the resulting voltages produced can cause appreciable amounts of noise, especially when a ceramic capacitor is used for noise bypassing. a ceramic capacitor produced figure 5s trace in response to light tapping from a pencil. similar vibration induced behavior can masquerade as increased output voltage noise. thermal considerations the lt3007s maximum rated junction temperature of 125c limits its power-handling capability. two components comprise the power dissipated by the device: 1. output current multiplied by the input/output voltage differential: i out ? (v in C v out ) 2. gnd pin current multiplied by the input voltage: i gnd ? v in gnd pin current is found by examining the gnd pin current curves in the typical performance characteristics section. power dissipation is equal to the sum of the two components listed prior. the lt3007 regulator has internal thermal limiting designed to protect the device during overload conditions. for con - tinuous normal conditions, do not exceed the maximum junction temperature rating of 125c. carefully consider all sources of thermal resistance from junction to ambi - ent including other heat sources mounted in proximity to the lt3007. for surface mount devices, heat sinking is table 2: measured thermal resistance for tsot-23 package copper area board area thermal resistance (junction-to-ambient) topside* backside 2500mm 2 2500mm 2 2500mm 2 65c/w 1000mm 2 2500mm 2 2500mm 2 67c/w 225mm 2 2500mm 2 2500mm 2 70c/w 100mm 2 2500mm 2 2500mm 2 75c/w 50mm 2 2500mm 2 2500mm 2 85c/w *device is mounted on the topside. 100ms/div v out 500v/div 3007 f05 v out = 0.6v c out = 22f i load = 10a calculating junction temperature example: given an output voltage of 3.3v, an input volt - age range of 12v 5%, an output current range of 0ma to 20ma and a maximum ambient temperature of 85c, what will the maximum junction temperature be? the power dissipated by the device is equal to: i out(max) (v in(max) C v out ) + i gnd (v in(max) ) where, i out(max) = 20ma v in(max) = 12.6v i gnd at (i out = 20ma, v in = 12.6v) = 0.3ma
lt3007 series 13 3007f for more information www.linear.com/lt3007 applications information in (but is limited by) the resistor divider that sets output voltage. current fows from the bottom resistor in the divider and from the adj pins internal clamp through the top resistor in the divider to the external circuitry pulling out below ground. if in is powered by a voltage source, out sources current equal to its current limit capability and the lt3007 protects itself by thermal limiting if neces - sary. in this case, grounding the shdn pin turns off the lt3007 and stops out from sourcing current. the lt3007 incurs no damage if the adj pin is pulled above or below ground by 50v. if in is left open circuit or grounded, adj acts like a 100k resistor in series with a diode when pulled above or below ground. in circuits where a backup battery is required, several different input/output conditions can occur. the output voltage may be held up while the input is either pulled to ground, pulled to some intermediate voltage or is left open circuit. current fow back into the output follows the curve shown in figure 6. if the lt3007 in pin is forced below the out pin or the out pin is pulled above the in pin, input current typically drops to less than 1a. this occurs if the lt3007 input is connected to a discharged (low voltage) battery and either a backup battery or a second regulator circuit holds up the output. the state of the shdn pin has no effect in the reverse current if out is pulled above in. so, p = 20ma(12.6v C 3.3v) + 0.3ma(12.6v) = 189.8mw the thermal resistance ranges from 65c/w to 85c/w depending on the copper area. so, the junction temperature rise above ambient approximately equals: 0.1898w(75c/w) = 14.2c the maximum junction temperature equals the maximum junction temperature rise above ambient plus the maximum ambient temperature or: t j(max) = 85c + 14.2c = 99.2c protection features the lt3007 incorporates several protection features that make it ideal for use in battery-powered circuits. in ad - dition to the normal protection features associated with monolithic regulators, such as current limiting and thermal limiting, the device also protects against reverse-input voltages, reverse-output voltages and reverse output-to- input voltages. current limit protection and thermal overload protec- tion protect the device against current overload condi - tions at the output of the device. for normal operation, do not exceed a junction temperature of 125c. the typical thermal shutdown circuitry temperature threshold is 160c. the in pin withstands reverse voltages of 50v. the device limits current fow to less than 30a (typically less than 1a) and no negative voltage appears at out. the device protects both itself and the load against batteries that are plugged in backwards. the shdn pin cannot be driven below gnd unless tied to the in pin. if the shdn pin is driven below gnd while in is powered, the output will turn on. shdn pin logic cannot be referenced to a negative rail. the lt3007 incurs no damage if out is pulled below ground. if in is left open circuit or grounded, out can be pulled below ground by 50v. no current fows from the pass transistor connected to out. however, current fows figure 6. reverse-output current output and adj voltage (v) 0 60 80 100 8 40 20 50 70 90 30 10 0 21 43 6 7 9 5 10 3007 f06 reverse current (a) out current adj current
lt3007 series 14 3007f for more information www.linear.com/lt3007 applications information typical applications keep-alive power supply last-gasp circuit fault tolerance the lt3007 regulators tolerate single fault conditions. shorting two adjacent pins together or leaving one single pin foating does not increase v out above its regulated value or cause damage to the lt3007 regulators. however, the application circuit must meet the requirements discussed in this section to achieve this tolerance level. tables 3 and 4 show the effects that result from shorting adjacent pins or from a foating pin, respectively. table 3: effects of pin-to-pin shorts pin numbers pin names effect comment 1-2 shdn-gnd lt3007 is in micropower shutdown, v out is off 2-3 gnd-gnd no effect. pins 2, 3 and 4 are normally tied to gnd 3-4 gnd-gnd no effect. pins 2, 3 and 4 are normally tied to gnd 5-6 in-nc no effect as long as nc is floating 6-7 nc-out no effect as long as nc is floating 7-8 out-adj v out decreases to 600mv as the top resistor in the v out divider is shorted lt3007 adjustable version 7-8 out-sense no effect as these two pins are normally shorted together lt3007 fixed voltage version. table 4: effects of floating pins pin number pin name effect comment 1 shdn lt3007 is in micropower shutdown, v out is off 2 gnd no effect as long as pins 3 or 4 are tied to gnd 3 gnd no effect as long as pins 2 or 4 are tied to gnd 4 gnd no effect as long as pins 2 or 3 are tied to gnd 5 in lt3007 has no input power, v out is off 6 nc no effect 7 out v out internal to lt3007 is @ v in . v out externally decreases to 0v 8 adj v out decreases to less than regulated v out lt3007 adjustable version 8 sense v out increases to @ v in unless an external clamp is added lt3007 fixed voltage version. in shdn 3.3v 3007 ta02 out 1f 2.2f sense gnd lt3007-3.3 no protection diodes needed! v in 12v load: system monitor, volatile memory, etc. in shdn 5v 3007 ta03 out fault 1f supercap 2.2f sense pwr to monitoring center sense gnd gnd lt3007-5 line power v line 12v to 15v d charge r limit line interrupt detect
lt3007 series 15 3007f for more information www.linear.com/lt3007 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 1.50 ? 1.75 (note 4) 2.80 bsc 0.22 ? 0.36 8 plcs (note 3) datum ?a? 0.09 ? 0.20 (note 3) ts8 tsot-23 0710 rev a 2.90 bsc (note 4) 0.65 bsc 1.95 bsc 0.80 ? 0.90 1.00 max 0.01 ? 0.10 0.20 bsc 0.30 ? 0.50 ref pin one id note: 1. dimensions are in millimeters 2. drawing not to scale 3. dimensions are inclusive of plating 4. dimensions are exclusive of mold flash and metal burr 5. mold flash shall not exceed 0.254mm 6. jedec package reference is mo-193 3.85 max 0.40 max 0.65 ref recommended solder pad layout per ipc calculator 1.4 min 2.62 ref 1.22 ref ts8 package 8-lead plastic tsot-23 (reference ltc dwg # 05-08-1637 rev a) please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
lt3007 series 16 3007f for more information www.linear.com/lt3007 ? linear technology corporation 2013 lt 0313 ? printed in usa linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax : (408) 434-0507 www.linear.com/lt3007 related parts part number description comments lt1761 100ma, low noise micropower ldo v in : 1.8v to 20v, v out = 1.22v, v do = 0.3v, i q = 20a, i sd < 1a, low noise: < 20v rms , stable with 1f ceramic capacitors, thinsot tm package lt1762 150ma, low noise micropower ldo v in : 1.8v to 20v, v out = 1.22v, v do = 0.3v, i q = 25a, i sd < 1a, low noise: < 20v rms , ms8 package lt1763 500ma, low noise micropower ldo v in : 1.8v to 20v, v out = 1.22v, v do = 0.3v, i q = 30a, i sd < 1a, low noise: < 20v rms , s8 package lt1764/lt1764a 3a, low noise, fast transient response ldos v in : 2.7v to 20v, v out = 1.21v, v do = 0.34v, i q = 1ma, i sd < 1a, low noise: < 40v rms , lt1764a version stable with ceramic capacitors, dd and to220-5 packages lt1962 300ma, low noise micropower ldo v in : 1.8v to 20v, v out(min) = 1.22v, v do = 0.27v, i q = 30a, i sd < 1a, low noise: < 20v rms , ms8 package lt1963/lt1963a 1.5a, low noise, fast transient response ldos v in : 2.1v to 20v, v out(min) = 1.21v, v do = 0.34v, i q = 1ma, i sd < 1a, low noise: < 40v rms , lt1963a version stable with ceramic capacitors, dd, to220-5, sot223 and s8 packages lt3008 20ma, 45v, 3a i q micropower ldo 300mv dropout voltage, low i q : 3a, v in : 2v to 45v, v out : 0.6v to 39.5v, thinsot and 2mm 3mm dfn-6 packages lt3009 20ma, 3a i q micropower ldo v in : 1.6v to 20v, low i q : 3a, v do = 0.28v, 2mm 2mm dfn and sc70-8 packages lt3020 100ma, low voltage vldo v in : 0.9v to 10v, v out(min) = 0.20v, v do = 0.15v, i q = 120a, i sd < 1a, 3mm 3mm dfn and ms8 packages lt3021 500ma, low voltage vldo v in : 0.9v to 10v, v out(min) = 0.20v, v do = 0.16v, i q = 120a, i sd < 3a, 5mm 5mm dfn and so8 packages LT3080/LT3080-1 1.1a, parallelable, low noise, low dropout linear regulator 300mv dropout voltage (2-supply operation), low noise: 40v rms , v in : 1.2v to 36v, v out : 0v to 35.7v, current-based reference with 1-resistor v out set; directly parallelable (no op amp required), stable with ceramic caps, to-220, sot-223, msop and 3mm 3mm dfn packages; LT3080-1 version has integrated internal ballast resistor lt3085 500ma, parallelable, low noise, low dropout linear regulator 275mv dropout voltage (2-supply operation), low noise: 40v rms , v in : 1.2v to 36v, v out : 0v to 35.7v, current-based reference with 1-resistor v out set; directly parallelable (no op amp required), stable with ceramic caps, msop-8 and 2mm 3mm dfn packages low duty cycle applications average power savings for low duty cycle applications 0ma to 10ma pulsed load, in = 12v typical application in shdn 2.2f 3.3v 3007 ta04a out 1f sense gnd lt3007-3.3 v in 12v low duty cycle pulsed load 0ma to 10ma duty cycle (%) 0.1 70 60 80 90 100 3007 ta04b 40 50 30 1 10 20 10 0 power savings (%) 10a i q 100a i q 30a i q

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