general description the LM317 are adjustable three - terminal positive -voltage regulators capable of supplying 1.5a over a differential voltage range of 3v to 40v. they are exceptionally easy to use and require only two external resistors to set the output voltage. both input and output regulation are better than standard fixed regulators. in addition to higher performance than fixed regulators, these regulators offer full overload protection available only in integrated circuits. included on the chip are current limit, thermal overload protection, and safe-area protection. all overload protection circuitry remains fully functional even if the adjustment terminal is disconnected. normally, no capacitors are needed unless the device is situated far from the input filter capacitors in which case an input bypass is needed. an optional output capacitor can be added to improve transient response. the primary applications of eac h of these regulators is that of a programmable output regulator, but by connecting a fixed resist or between adjustment terminal and the output te rminal, each device can be used as a precision current regulator. even though the regulator is floating and sees onl y the input-to-output differential voltage, use of these devices to regulate output voltages that would cause the maximum-rated differential voltage to be exceeded if the output became shorted to ground is not recommended. features ? output voltage range adjustable from 1.2 v to 37 v. ? output current capability of 1.5 a max. ? input regulation typically 0.01 % per input - volt change. ? output regulation typically 0.1 %.. ? peak output current constant over temperature range of regulator. ? popular 3-lead to-220 package ? ripple rejection typically 80 db. pin description 1 of 4 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification LM317
typical application data note a: use of an input bypass capacitor is recomm ended if regulator is far from filter capacitors. note b: use of an output capacitor impr oves transient res ponse but is optional. note c: output voltage is ca lculated from the equation: vref equals the difference between th e output and adjustment terminal absolute maximum ratings over operating temperature range (unless otherwise noted) parameter maximum units input-to-output differential voltage, vi - vo 40 v continuous total dissipation at 25 c free-air temperature 2 w continuous total dissipation at (o r below) 25 c case temperature 15 w operating free-air, case, or virtual junction temperature range 0 to 125 c storage temperature range -65 to 150 c 2 of 4 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification LM317
recommended operating conditions parameter lm 317 units min max output current, io 10 1500 ma operating virtual junction temperature, tj 0 125 c electrical characteristics electrical characteristics over recommended r anges of operating virtual junction temperature (unless otherwise noted) (note 1) parameter test conditions* LM317 units input regulation (note 2) vi-v0=3 v to 40 v, (note 3) tj = min to max min typ max l0 = 10 ma to 1.5 a 0.01 0.04 %/ v ripple rejection vo=10 v, f=120 hz 0.02 0.07 vo=10 v, f=120 hz 10- f capacitor between adj and ground 65 db 66 80 output regulation lo = 10 ma to 1.5 a, tj= 25 c, (see note 3) vo 5 v 5 25 mv vo > 5 v 0.1 0.5 % lo = 10 ma to 1.5 a, (note 3) vo 5 v 20 70 mv vo > 5 v 0.3 1.5 % output voltage change with temperature tj = min to max 1 % output voltage long-term drift (note 4) after 1000 h at tj = max and vi-vo =40 v 0.3 1 % output noise voltage f= 10 hz to 10 khz, tj =25 0.003 % minimum output current to maintain regulation vi-vo = 40 v 3.5 10 ma peak output current vi-vo 15 v 1.5 2.2 a vi-vo 40 v, tj =25 0.1 5 0.4 adjustment-terminal current 60 100 a change in adjustment-terminal current vi-vo=2.5 v to 40 v, lo = 10 ma to 1.5 a 0.2 5.0 a reference voltage (output to adj ) vi-vo = 3 v to 40 v, lo=10 ma to 1.5 a, p 15w 1.2 1.25 1.3 v 3 of 4 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification LM317
* unless otherwise noted, these specif ications apply for the following test conditions: vi - v0 = 5v and io = 0.5 a. for conditions shown as min or max, use the appropriate value specified under recommended operating conditions. note 1: all characteristics are measured with a 0.1 - f capacitor across the input and a 1 - f capacitor across the output. note 2: input regulation is expressed here as the percentage change in output voltage per 1 - v change at the input. note 3: pulse testing techniques are used to maintain the junction temperature as close to the ambient temperature as possible. thermal effects must be taken into account separately. note 4: since long-term drift cannot be measured on the individual devices prior to shipment, this specification is not int ended to be a guarantee or warranty. it is an engineering estimate of the average drift to be expected from lot to lot. ordering information ordering number package marking LM317 to - 220 LM317 package description 4 of 4 4008-318-123 sales@twtysemi.com http://www.twtysemi.com product specification LM317
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