LM317L

TIGER ELECTRONIC CO.,LTD 3-TERMINAL A DJUSTA BLE R EGULAT O R L M 317L / L M317 LF DESCRIPTION T he L M 317 is an adjustable 3-terminal positive voltage regulator capable of s upply i ng 100m A over a 1.2V to 37V output range. It is exceptionally e asy t o use and r equires only t wo external resistors to set the output voltage. Further, it em ploy s i nternal current lim iting, therm a l shutdown and safe area com p ensation, m a king it e ssentially blow-out proof. Also, the L M 317 is available packaged in a standard T O-92 transistor package which is easy to use. T he L M 317 serves a wide variety of applications including local, on card r egulation. This device can also be used to m a ke a program m a ble output regulator, or b y c onnecting a fixed resistor between the adjustm ent and output, the L M 317 can be u sed as a precision current regulator. FEATURES A djustable output down to 1.2V G uaranteed 100 m A o utput current L ine regulation ty pically 0 .01%/V L oad regulation ty pically 0 .1% C urrent lim it constant with tem p erature E lim inates the need to stock m a ny voltages 8 0 dB ripple rejection O utput is short circuit protected PIN CONNECTION LM317L LM317LF 1/14 LM317 S CHEMATIC D IAGRAM 2/14 LM317 A BSOLUTE MAXIMUM RATINGS ( Ta=25 ° C) C haracteristic I nput-Output Voltage Differential P ower Dissipation O perating Junction Temp erature Range L ead Temperature (Soldering, 4 seconds) S torage Temp erature Range S ymbol V i/Ao PD Tj TL Tstg M in. - 0.3 - 25 - 55 M ax. 40 I nternally Limited 1 25 2 50 1 50 U nit V W °C °C °C E LECTRICAL CHARACTERISTICS ( unless otherwise specified: Vi-Vo=5.0V; Io=40mA; Tj=0~125 ° C; Imax=100mA and Pmax=625mW ) C haracteristics Line Regulation Load Regulation A djustment Pin Current Adjustment Pin Current Change Reference Voltage L ine Regulation Load Regulation Te mp erature Stability M inimu m Current C urrent Limit R ms Noise % of Vo R ipple Rejection L ong-Term Stability Load Test conditions T j=25 ℃ , I L ≤ 20mA 3 V ≤ (V I N -V O U T ) ≤ 40V S ymbol Min. R egline - Typ. 0 .01 0 .1 50 0 .2 M ax. 0 .05 0 .5 1 00 6 U nit % /V % μA μA T j=25 ℃ , 5mA ≤ I O U T ≤ I M A X Regload I adj 5 mA ≤ I L ≤ 100mA 3 V ≤ (V I N -V O U T ) ≤ 40V, ∆ I adj P ≤ 625mW 3 V ≤ (V I N -V O U T ) ≤ 40V, 5 mA ≤ I O U T ≤ 100mA, V ref 1 .15 P ≤ 625mW 3 V ≤ (V I N - V O U T ) ≤ 40V,I ≤ R egline 20mA R egload 5 mA ≤ I O U T ≤ 100mA T M I N ≤ Tj ≤ T M A X ( V I N -V O U T ) ≤ 40V 3 V ≤ (V I N -V O U T ) ≤ 15V 3 V ≤ (V I N -V O U T ) ≤ 13V ( V I N -V O U T ) =40V T j=25 ℃ , 10Hz ≤ f ≤ 10KHz V O U T =10V, f=120Hz, C A D J =0 C A D J =10 μ F T j=125 ℃ , 1000Hours Ts I L min I max N RR S 40 25 66 - 1.25 0 .02 0 .3 0 .65 3 .5 1 .5 200 50 0 .003 65 80 0 .3 1 .35 0 .05 1 .2 17 6 260 70 0 .008 80 V % /V % % mA mA mA % dB % 1 3/14 LM317 APPLICAT ION INFORMAT ION 1 . B asic circuit operation I n operation, the L M 317 develops a nominal 1.25V reference voltage, Vref, between t he output and adjustm e nt term inal. The reference voltage is im pressed across program r esistor R1 and, since the voltage is constant, a constant current I1 then flows through t he output set resistor R2, giving an output voltage of Vout=Vref(1+R2/R1)+Iadj* (R2) S ince the 100 µ A current from t he adjustm e nt t erm inal represents an error term, the L M 317 w as designed to m i nim i ze Iadj and m a ke it very c onstant with line and load changes. To do this, a ll quiescent operating current is returned to the o utput establishing a m i nim u m l oad current r equirem e nt. If there is insufficient load on the o utput, t he o utput w ill r ise. 2. L oad R egulation T he L M 317 is capable of providing extremely good load regulation, but a few p recaut i ons p erform ance. a re nee d ed to For best o bt a in m a xi m u m the Figure: B asic c ircuit c onfiguration VIN LL 317L W VOU ADJ I1 VRE R2 R1 V OU I AD J perf orm a nce, p rogramm i ng resistor ( R1) shoul d be co nne cted as clos e to the r egula t or as p ossi ble to V IN LM317L W317L VIN VT OU ADJ Rs VOUT R1 240 m i ni m i ze line drops which e f fecti v ely appear i n s eries with the reference, t h ere b y degradi n g r egulat io n. T he gro und e nd o f R2 ca n be R2 r eturned n e ar the loa d g roun d to p r ovide rem o te g roun d se n s ing a n d i m prove loa d r eg u la tio n in output lead A 0 . 1 µ F disc or 1. 0 µ F tant alum i npu t by pas s c apac itor ( Cin) is re co m m e nded t o r educe the sensitivity t o input line im pedance. T h e ad j u stm e nt term inal m a y b e by passe d to gro u n d t o im pro v e ripp le rejecti o n . T his ca paci tor (Cadj) p revents ri pple from b ein g am plified as t h e out pu t v o lta ge is i ncrease d . A 1 0 µ F cap acitor s ho u l d i m prove r ipple r ejec tion a b o u t 1 5dB a t 1 2 0Hz i n a 4/14 R eg u lat o r w ith l i ne r esistance 3 .External capacitors LM317 10V application. A lthou gh t h e L M 317 is stable with no output capacitance, like any feedback c ircuit , c er tain va lues o f e x terna l c a paci ta nce ca n c aus e e xcessive r inging. A n o utput c apac ita nce ( Co) in t h e form o f a 1.0 µ F tantal um o r 25 µ F alum inu m e le c trolytic c apacitor on the output swam ps this effect and insures stability. 4 . Protection Diodes W hen external capacitors are used with an y IC regulator it is som e tim es necessary t o add protection diodes to prevent the capacitors from d ischarging through low c urrent points into the regulator. Most 10 µ F capacitors have low enough internal s eries resistance to deliver 20A spikes wh en shorted. Although the surge is short, t here is enough energy t o dam a ge parts of the IC. W hen an output capacitor is connected to a regulator and the input is shorted, the o utput capacitor will discharge into the output of the regulator. The discharge current d epends on the value of the capacitor, the output voltage of the regulator, and the rate of decrease of Vin . In the L M 317, t his discharge path is through a large junction that i s able to sustain a 2A surge with no probl em . This is not true of other ty pes of p ositive regulators. For output capacitors of 25 µ F or less, the L M 317’s ballast r esistors and output structure lim it the peak current to a low enough level so that there i s no need to use a protection diode. T he by pass capacitor on the adjustm e nt term inal can discharge through a low c urrent junction. Discharge occurs when e ither the input or output is shorted. Internal to the L M 317 is a 50 Ω r esistor which limits t he peak discharge current. No protection is n eeded for output voltages of 25V or less and 1 0 µ F capacitance. Figure in right shows an L M 317 with protection diodes included for u se with outputs greater than 25V and high v alues of output capacitance. R egulator w ith p rotection d iodes D1 VIN IN400 VOU D2 T VIN LM317L W317L VOU ADJ T IN400 R2 10u R1 240 + C1 C2 5/14 LM317 APPLICAT ION CIRCUIT * Sets m a xim u m Vout Digitally Selected Outputs High Gain Amplifier 1 2 ≤ R 1 ≤ 2 40 Adjustable Current Limiter Precision Current Limiter S low T u rn-on 1 5V R egulator I m proved R ipple R ejection +Sold t antalum *Discharges C1 if output is shorted to ground Adjustable Regulator with 6/14 LM317 Short circuit current is approximately 600mV/R3, At 25mA output only 3/4V of drop occurs in R3 and R4 H igh S t ability 1 0V R egulator A djustable R egulator w ith C urrent L im iter 0V~30V Regulator Current Power Follower A djusting Multiple on-Card Regulators with Single Control 7/14 LM317 * Minim um l oad current=2m A 1 00m A C urrent R egulator 1.2V~12V R egulator w ith Minimum Program Current 50m A c onstant C urrent Battery Charger for Nickel-Cadmium Batteries *Minimum output=1.2V *Sets peak current, Ipeak=0.6V/R1 **1000µF is recommended to filter out any input transients 5 V L ogic Regulator with Electronic Shutdown C urrent Lim ited 6V C har ger 8/14 LM317 S hort Circuit Protected 80V S upply Q1,Q2:NSD134 or similar C 1 , C 2 : 1 µ F, 2 0 0 V m y l a r * * *Heat sink B asic High Vo ltage Regulator 9/14 LM317 Q1,Q2:NSD134 or similar C 1 , C 2 : 1 µ F, 2 0 0 V m y l a r * * * H e a t s i n k * * M y l a r i s a r e g i s t e r e d t r a d e m a r k o f D u P o n t C o . P recision H igh Vo ltage R egulator T r acking R egulator Regulator w ith T r im m a ble o utput Vo ltage 10/14 LM317 P recision Reference with Short-Circuit Proof Output Adjustable Regulator Protected (Bulletproof) Lamp Driver Lamp Flasher 11/14 LM317 C HARACTERISTICS CUR VES 12/14 LM317 P recision Reference with Short-Circuit Proof Output Adjustable Regulator Protected (Bulletproof) Lamp Driver Lamp Flasher 11/14 LM317 O UTLINE DRAWING TO-92 Unit:mm S OT- 89-3L U nit:m m 14/14