bay linear, inc 2418 armstrong street, livermore, ca 94550 tel: (925) 606-5950, fa x: (925) 940-9556 www.baylinear.com 3-terminal 1.5amp adjustable voltage regulator LM317 packaging information ordering information device package type output LM317t to-220 1.5 amp LM317n sot-223 1.0 amp LM317s to-263 1.5 amp LM317d to-252 1.5 amp sot-223 vs. to-252 package description the bay linear LM317 are monolithic integrated circuit in to- 220, to-252, sot-223 and d2pak packages intended for use as positive adjustable voltage regulators. they are designed to supply more than 1.5a of load current with an output voltage adjustab le over a 1.2 to 37v range. the nominal output voltage is selected by means of only a resistive divider, making the device exceptionally easy to use and eliminating the stocking of many fixed regulators. features ? output current of 1.5a ? output voltage tolerance of 5% ? adjustable output 1.2v to 37v ? 0.1% load & line regulation ? internal short-circuit limited ? current limit ? offer in plastic to-252, to-220, sot-223 & to-263 ? direct replacement for LM317 applications ? post regulator for switching dc/dc converter ? bias supply for analog circuits bay linear inspire the linear power top view to-263-3 ( 1 bay linear 2 3 top view to-263-3 (s) 1 bay linear 2 3 top view to-263-3 ( 1 bay linear 2 3 top view to-263-3 (s) 1 bay linear 2 3 1. adj 2. output 3. input
bay linear, inc 2418 armstrong street, livermore, ca 94550 tel: (925) 606-5950, fa x: (925) 940-9556 www.baylinear.com LM317 absolute maximum rating parameter LM317 unit power dissipation inte rnally limited input voltage differential +40v, -0.3v v operating free-air, case, virtual junction temp. 0 to 150 storage temperature range -65 to 150 lead temperature 1.6 mm from case for sec. 260 c electrical characteristics (LM317) parameter symbol conditions min typ max unit reference voltage v o 3v (v in -v out ) 40v 10ma i out i max , p p max 1.20 1.25 1.30 v 0.01 0.02 line regulation ? v o 3v (v in -v out ) 40v (note 4) 0.02 0.05 %/v 0.1 0.3 load regulation ? v o 10ma i out i max (note 4) 0.3 1 % % v i = 10v,, f=120hz c adj =0f 65 db ripple rejection rr v i = 10v,, f=120hz c adj =10f 66 80 db thermal regulation 20ms 0.03 0.07 %w adjustment pin current 50 100 a adjustment pin current change 10ma i out i max , 3v (v in -v out ) 40v 0.2 5 a temperature stability t min t j t max 1 % long term stability t j =125 c, 1000 hrs 0.3 1 % rms output noise % of v out 10hz f 10khz 0.003 % minimum load current (v in -v out ) =40v 3.5 5 ma (v in -v out ) 15v p d p max 1.5 2.2 a maximum load current (v in -v out ) 40v p d p max 0.4 a
bay linear, inc 2418 armstrong street, livermore, ca 94550 tel: (925) 606-5950, fa x: (925) 940-9556 www.baylinear.com LM317 application notes: the LM317 provides an internal reference voltage of 1.25v between the output and adjustments terminals. this is used to set a constant current flow across an external resistor divider show below, giving an output voltage vo of: v o = v ref ( 1 + r 2 r 1 ) + i ad j r 2 the device was designed to minimize the term i adj ( 100 m a max) and to maintain it very constant with line and load changes. usually, the error term i adj v r 2 can be neglected. to obtain the previous requirement, all the regulator quiescent current is returned to the output terminal, imposing a minimum load current condition. if the load is insufficient, the output voltage will rise. since the LM317 is a floating regulator and ? sees? only the input- to- output differential voltage, supplies of very high voltage with respect to ground can be regulated as long as the maximum input- to- output differential is not exceeded. furthermore, programmable regulator are easily obtainable and, by connecting a fixed resistor between the adjustment and output, the device can be used as a precision current regulator. in order to optimise the load regulation, the current set resistor r1 show below should be tied as close as possible to the regulator, while the ground terminal of r2 should be near the ground of the load to provide remote ground sensing. performance may be improved with added capacitance as follow: an input bypass capacitor of 0.1f an adjustment terminal to ground 10f capacitor to improve the ripple rejection of about 15 db ( c adj ). an 1f tantalium ( or 25 faluminium electrolitic) capacitor on the output to improve transient response. in additional to external capacitors, it is good practice to add protection diodes, as shown in below. d1 protect the device against input short circuit, while d2 protect against output short circuit for capacitance discharging.
bay linear, inc 2418 armstrong street, livermore, ca 94550 tel: (925) 606-5950, fa x: (925) 940-9556 www.baylinear.com advance information - these data sheets contain descriptions of products that are in development. the specifications are based on the engineering ca lculations, computer simulations and/ or initial prototype evaluation. preliminary information - these data sheets contain minimum and maxi mum specifications that are based on the initial device characterizations. these lim its are subject to change upon the completion of the full characterization over the specif ied temperature and supply voltage ranges. the application circuit examples are only to explain the repres entative applications of the de vices and are not intended to gua rantee any circuit design or permit any industrial property ri ght to other rights to execute. bay linear takes no responsibility for any problems related to any industrial property right resulting from the use of the contents shown in the da ta book. typical parameters can and do vary in different applications. customer?s technical experts must validate all operating parameters including ? typical? for each customer applic ation. life support and nuclear policy bay linear products are not authorized fo r and should not be used within life suppor t systems which are intended for surgical implants into the body to support or sustain life, in aircraft, space equipment, submarine, or nuclear facility applications wi thout the specific written consent of bay linear president.
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