features low dropout voltage load regulation: 0.05% typical trimmed current limit on-chip thermal limiting standard sot-223, to-220, and to-252 packages three-terminal adjustable or ?ed 1.8v, 2.5v, 2.85v, 3.3v, 5v applications active scsi terminators high ef?iency linear regulators post regulators for switching supplies battery chargers 12v to 5v linear regulators motherboard clock supplies description the lr1117a and lr1117a-1.8, -2.5, -2.85, -3.3 and -5 are low dropout three-terminal regulators with 1a output current capability. these devices have been optimized for low voltage where transient response and minimum input voltage are critical. the 2.85v version is designed speci?ally to be used in active terminators for scsi bus. current limit is trimmed to ensure speci?d output current and controlled short-circuit current. on-chip thermal limiting provides protection against any combination of overload and ambient temperatures that would create excessive junction temperatures. unlike pnp type regulators where up to 10% of the output current is wasted as quiescent current, the quiescent current of the lr1117a ?ws into the load, increasing ef?iency. the lr1117a series regulators are available in the industry-standard sot-223, to-220, and to-252 (dpak) power packages. typical applications v in = 12v v in v out adj 9v at 1a lr1117a 10 f22 f r1 124 ? r2 768 ? v in = 12v v in v out gnd 5v at 1a lr1117a-5 10 f ++ + + 22 f v out = v ref (1 + r2/r1) + i adj ?r2 lr1117a 1a adjustable/fixed low dropout linear regulator leshan radio company, ltd. 1/9
pin assignments *with package soldered to 0.5 square inch copper area over backside ground plane or internal power plane, ja can vary from 30?/w to more than 50?/w. other mounting techniques may provide better thermal resistance than 30?/w. absolute maximum ratings figure 1. absolute maximum safe operating area parameter min. max. unit v in 18 v (v in ?v out ) * i out see figure 1 operating junction temperature range 0 125 c storage temperature range -65 150 c lead temperature (soldering, 10 sec.) 300 c front view front view 4-lead plastic sot-223 v out (v) i out (a) 2/9 leshan radio company, ltd. lr1117a
electrical characteristics operating conditions: v in c unless otherwise speci ed. the ? cations which apply over the speci ed operating temperature range. notes: 1. see thermal regulation specifications for changes in output voltage due to heating effects. load and line regulation are measured at a constant junction temperature by low duty cycle pulse testing. 2. line and load regulation are guaranteed up to the maximum power dissipation (18w). power dissipation is determined by input/output differential and the output current. guaranteed maximum output power will not be available over the full input/ output voltage range. 3. lr1117a only. 4. output current must be limited to meet the absolute maximum ratings of the part. parameter conditions min. typ. max. units reference voltage 3 1.5v v out ) ? ? ? ? ? ? ? v out ) = 2v, 10ma ? ? ? v out ) = 2v ? ? v out ) ? v out ) ? ? v out ) = 3v, i out = 1a 60 72 db thermal regulation t a = 25 ? 3/9 leshan radio company, ltd. lr1117a
typical performance characteristics 1.5 0.10 0.05 0 -0.05 -0.10 -0.15 -0.20 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 1.260 1.255 1.250 1.245 1.240 1.235 1.230 1.225 1.220 1.215 1.210 0 0 0.6 0.8 0.4 0.2 output current (a) junction temperature ( ? figure 2. dropout voltage vs. output current figure 3. load regulation vs. temperature figure 4. reference voltage vs. temperature figure 5. output voltage vs. temperature figure 6. minimum load current vs. temperature figure 7. adjust pin current vs. temperature 4/9 leshan radio company, ltd. lr1117a
typical performance characteristics (continued) 2.0 1.75 1.5 1.25 1.0 short-circuit current (a) junction temperature ( ? figure 8. short-circuit current vs. temperature figure 9. ripple rejection vs. frequency figure 10. maximum power dissipation figure 11. stability region (soa) vs. esr of the c out 5/9 leshan radio company, ltd. lr1117a
mechanical dimensions 4-lead sot-223 package a .071 symbol inches min. max. min. max. millimeters notes a1 .181 .033 b .025 c .090 e .130 .148 e h .264 .287 .115 .124 .033 .041 10 1.80 4.80 .840 .640 2.29 3.30 3.71 6.71 7.29 .012 .310 2.95 3.15 .840 1.04 10 6/9 leshan radio company, ltd. lr1117a
mechanical dimensions (continued) 3-lead to-220 package a .140 .190 3.56 4.83 symbol inches min. max. min. max. millimeters notes b .015 .040 .38 1.02 .070 1.78 b1 .045 1.14 c1 .014 .022 .36 .56 p .139 .161 3.53 4.09 d .560 .650 14.22 16.51 .380 .420 9.65 10.67 .090 .110 2.29 2.79 e e e1 .190 .210 4.83 5.33 .045 1.14 .020 .055 .51 1.40 p c1 j1 d f a (5x) notes: 1. dimension c1 apply for lead finish. 7/9 leshan radio company, ltd. lr1117a
mechanical dimensions (continued) 3-lead to-252 package d d1 gage plane notes: unless otherwise specified a) all dimensions are in millimeters. b) this package conforms to jedec, to-252, issue c. variation aa & ab, dated nov. 1999. c) dimensioning and tolerancing per asme y14.5 1994. d) heat sink top edge could be in chamfered corners or edge protrusion. e) dimensions l3, d, e1 & d1 table: option aa option ab 0.89 1.27 1.52 2.03 5.97 6.22 5.33 5.59 4.32 min 3.81 min 5.21 min l3 d e1 d1 4.57 min 0.51 seating plane detail a (1.54) 1.78 1.40 0.61 0.48 10 90 8/9 leshan radio company, ltd. lr1117a
ordering information product number package lr1117adx to-252 in tape and reel lr1117asx sot-223 in tape and reel lr1117ad18x to-252 in tape and reel lr1117as18x sot-223 in tape and reel LR1117AD25X to-252 in tape and reel lr1117as25x sot-223 in tape and reel lr1117as5x sot-223 in tape and reel lr1117ad5x to-252 in tape and reel lr1117as33x sot-223 in tape and reel lr1117ad33x to-252 in tape and reel lr1117ad285 to-252 lr1117as285 sot-223 lr1117at to-220 lr1117at18 to-220 lr1117at25 to-220 lr1117at33 to-220 9/9 leshan radio company, ltd. lr1117a
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