LM317 3-Terminal Adjustable Output Positive Voltage Regulators (THREE-TERMINAL ADJUSTABLE OUTPUT POSITIVE VOLTAGE REGULATORS ) T he LM317 is adjustable 3-terminal positive voltage external resistors to set the output voltage. Further, it regulator capable of supplying in excess of 1.5 A employs internal current limiting, thermal shutdown and over an output voltage range of 1.2 V to 37 V. This voltage safe area compensation, making it essentially blow-out regulator is exceptionally easy to use and require only two proof. (FEATURES ) (PIN ARRANGEMENT ) Output Current in Excess of 1.5 Ampere Output Adjustable between 1.2 V and 37 V Z SUFFIX e Internal Thermal Overload Protection Aah ACKAGE Internal Short-Circuit Current Limiting Constant with Temperature Output Transistor Safe-Area Compensation PIN LADJUST Floating Operation for High Voltage Applications ; eg Standard 3-lead Transistor Packages , Eliminates Stocking Many Fixed Voltages (CIRCUIT SCHEMATIC ) STANDARD APPLICATION Vin Vout * = Cin is required if regulator is | d an appreciable di from power supply filter. ** = Co is not needed for stability, however it does improve transient response. Vee = 1.25 V (1+ Raf Ri) + Tag Ra Since I, is controlled to less than 100 ,1A, the error associated with this term is negligible in most applications 2-28io (ORDERING INFORMATION Tested Operating Device Temperature Range Package LM317CZ | T:=0% to 125% TO-220 (MAXIMUM RATINGS ) Rating Symboi Value Unit Input-Output Voltage Differential Vi- Vo 40 Vde Power Dissipation Pp Internally Limited Operating Junction Temperature Range Ty , 0to+ 150 C Storage Temperature Range Tstg -65 to +150 %C LM317 3-Terminal Adjustable Output Positive Voltage Regulators (LM317 ELECTRICAL CHARACTERISTICS (V, - Vo = 5.0 V; In = 0.5 A for TO-220 packages; T; = Tiow.tO Thigh [Se Note 1]; Inax and Pra, per Note 2; unless otherwise ) specified.) Characteristic Figure | Symbol Min. Typ. Max. Unit Line Regulation (Note 3) 1 REGline _ 0.01 0.04 WV Ta = 25C, 3.0V sib 540V Load Regulation (Note 3) 2 REGload Ta = 25 C, 10 mA S Io S Imax Vo $ 5.0 - 5.0 25 mV Vo 2 5.0 - 0.1 0.5 %V Thermal Regulation (T, =+ 25C) _ 0.03 0.07 %W 20 ms Pulse Adjustment Pin Current 3 Lagi - 50 100 wA Adjustment Pin Current Change 12 Alagj - 0.2 5.0 wa 2.5V 5 Vi-Vos40V 10mA < It < In, Po sP Reference Voltage (Note 4) 3 Veet 1,225 1.25 1.275 v 3.0VS Vie Vos 40V , 1OmAS1]o0Slaax, Pp < Paux Line Regulation (Note 3) 1 REGline -- 0.02 0.07 %V 3.0V<Vi-Vos40V Load Regulation (Note 3) 2 REGload 10mA $ Io S$ Inx Vos 5.0V - 20 70 mV Vo 25.0 V - 0.3 1.5 %V 2-29FO de ricniscs LM317 3-Terminal Adjustable Output Positive Voltage Regulators SCHEMATIC DIAGRAM , ? , Vin 05 0 a 04 pe & 6.3V od 6 ok 12K3 op 313K fs ; $200 [ oe 5 * PEP, gsr] * 6.3v a 2 6.8K 7 - 2 . SOpFi30pF; 6.aV J ; , $ 10s * 2 12.5K 34 3 190 -F , $0.1 Vout Adjust FIGURE 1- LINE REGULATION AND LINE TEST CIRCUIT Vou Vor Line Regulation(%/V)= yy =100 ak y rh oH Vu Vin Vout Seve LM317 2 e 240 Pulse Testing Required: Cin im Co 1% Duty Cycie = = Re is Suggested. 0.14F Ie 2-30LM317 3-Terminal Adjustable Output Positive Voltage Regulators io (ELECTRICAL CHARACTERISTICS ) (VrVo = 5.0 V; Io.= 0.5A for TO-220 packages; T; = Tiow tO Thigh (Se Note 1]; Tmax ANd Pre per Note 2; unless otherwise specified.) Characteristic Figure Symbol Min Typ Max Unit Temperature Stability Tow < Tr < Tish) 3 Ts ~ 0.7 - VV Minimum Load Current to 3 Tomin - 3.5 10 mA Maintain Regulation (V1 - Vo = 40 V) Maximum Output Current 3 Trnax A Vi- Vos 15V, Pp < Pr 1.5 2.2 - Vi- Vo = 40V, Pps Prox, Ta = 25C 0.15 0.4 - RMS Noise, % of Vo - N - 0.003 mV Ta =25C, 10 Hz < f < 10 KHe : Ripple Rejection, Vo= 10 V, f= 120Hz 4 RR dB (Note 5) ; Without Cag , ~- 65 - Cag = 10 pF 66 80 - Long-Term Stability, T; = Tria, (Note 6) 3 5 -- 0.3 1.0 %1.0K T, =25C for Endpoint Measurements Hrs. Thermal Resistance Junction to Case - Rare ~ 5.0 - Cw NOTES: (1) Throw = 0C Thigh = + 125C (2) Imax = 1S A Prax =20 W (3) Load and line regulation are specified at constant junction temperature. Changes in Vo due to heating effects must be taken into account separately. Pulse testing with low duty cycle is used. (4) Selected devices with tightened tolerance reference voltage available. (5) Cray, when used, is connected between the adjustment pin and ground. {6) Since Long-Term Stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from lot to lot. 2-31LM317 3-Terminal Adjustable Output Positive Voltage Regulators o FIGURE 2 - LOAD REGULATION AND 4 1,.,/LOAD TEST CIRCUIT Load Regulator (mV)=Vo(min,Load)Vo(max.Load) Vo(min,.Load)~Vo(max,Load} Load Regulator (%Voj= x100 Vo(min,Lead) Vou (min.Load) vi Vi Vout Vou (max.Load) 2 LM317 Cr) 240 JL Cin 1% Co -_ > Re . 0.1 ur 1eF (min.Load) *Pulse Testing Required: 1% Duty Cycle is Suggested. FIGURE 3 - STANDARD TEST CIRCUIT Vin LM317 Vout _ @) Ce) Cin vi > O.1HF Pulse Testing Required: To Calculate R2: Vomlaer R2+1.250V is : 1% Duty Cycle is Suggested Nina neers + aN FIGURE 4 - RIPPLE REJECTION TEST CIRCUIT won, 14V Vout j ou tm 120Hz Vin LM317 pi Adjust He 1002 Rie 240 x = nO 7 L Toe: Thee } Acar Tour R2 l 1% *D1 Discharges Cans Uf Gutput is Sherted to Ground. 2-32LM317 3-Terminal Adjustable Output Positive Voltage Regulators FO Me ricnisce FIGURE 5-LOAD REGULATION FIGURE 6-CURRENT LIMIT 4 = ew (04 ~ 8 oz 3 3 e ce z = 0.2 C2 2 & 5 -0.4 z = 5 -1 a ~75 -80 ~2 7 o 40 5 5 0 25 50 100125 150 VI -Va.INPUT-OUTPUT VOLTAGE DIFFERENTIAL (Vde) Tz JUNCTION TEMPERATURE (C) FIGURE 7-ADJUSTMENT PIN CURRENT FIGURE 8-DROPOUT VOLTAGE 3. 70 65 60 535 50 45 1.56 40 Japs ADJUSTMENT PIN CURRENT (uA) UL Poms 35 -75 -50-25 9 25 50 75 100125 150 Td JUNCTION TEMPERATURE (C) V1 -Vo.INPUT-OUTPUT VOLTAGE DIFFERENTIAL{Vde) -7 ~50 -25 0 25 50 75 100125 150 TJ JUNCTION TEMPERATURE(C) FIGURE 9-TEMPERATURE STABILITY FIGURE 10-MINIMUM OPERATING CURRENT 1 = . = g S 1.250 @ 5 oe 3 zo g 1.240 5 2.5 me oo e 3 18 & 1.230 2 10 i Sos 1.220 -7E -50 -25 0 25 S80 75 100125 150 0 10 20 30 40 W=Vo.INPUT-OUTPUT VOLTAGE DIFFERENTIAL (Vdc) Ti JUNCTION TEMPERATURE (*C) 2-33LM317 3-Terminal Adjustable Output Positive Voltage Regulators FO deovicnisce FIGURE 11-RIPPLE REJECTION versus FIGURE 12-RIPPLE REJECTION versus OUTPUT VOLTAGE OUTPUT CURRENT ~ 3 =! 3 5 2 60 5 Vi-Voms a a TL =S00mA e & (= 120Hz 60 Ts n2stc ai . a Q gol vesisy & a Vom 10V a ~ $s 120H2 S Fd 20 T2225C 0 0 0 5 10 15 20 25 30 3 0.04 OL 1 10 Vo.OUTPUT VOLTAGE - lo.QUTPUT CURRENT(A) FIGURE 13-RIPPLE REJECTION versus FIGURE 14-OUTPUT IMPEDANCE FREQUENCY 100 80 views 5 115V 2 Vou 10 z z 60 T1028 a #10uF a B 40 5 3 : & 20 & & 6 10 10 100 1K 1GK100K 1M 10N 10 100 1K 10K 100K iM {FREQUENCY (Hz) 1. FREQUENCY (Hz) FIGURE 15-TEMPERATURE STABILITY FIGURE 16-LOAD TRANSIENT RESPONSE g ta is g ot = PF us Se cE =F Be te EE a a 05 5 5 {0 38 8 -0.8 CLeO:NITHOUT gL 8 Eris = BS 10 ag z Z 0.8 3 5 3 a t. TIME(us) . 1.TIME(us) 2-34FS Meoricnisce (APPLICATIONS INFORMATION BASIC CIRCUIT OPERATION The LM317 is a 3-terminal floating operation, the LM317 develops and maintains a nominal regulator. In 1.25 volt reference (V,,) between its output and adjustment terminals. This reference voltage is converted to a programming current ( Iproa ) by R, (see Figure 17), and this constant current flows through R, to ground. The regulated output voltage is given by: . R. Vou = Vref (1+ )+ Tag Ra Ry Since the current from the adjustment terminal (1,4) represents an error term in the equation, the LM317 was designed to control Ig to less than 100 4A and keep it constant. To do this, all quiescent operating current is retumed to the output terminal. This imposes the load current is less than this minimum, the output voltage will requirement for a minimum load current. If the rise. Since the LM317 is a floating regulator, it is only the voltage differential across the circuit which is important tp performance, and operation at high voltages with respect to ground is possible. FIGURE 17 -BASIC CIRCUIT CONFIGURATION Vin. Vout LM317 77 Vref Sri Adjuet Jim: ven Tape R2 $ | Veet=1.25V TYPICAL EXTERNAL CAPACITORS A 0.1pF disc or 1pF tantalum input bypass capacitor (Ca) is recommended to reduce the sensitivity to input line impedance, : The adjustment terminal may be bypassed to ground to improve ripple rejection. This capacitor (Cap) prevents tipple from being amplified as the output voltage is rejection about 15dB at 120 Hz ina 10 volt application. LM317 3-Terminal Adjustable Output Positive Voltage Regulators ) increased. A l0uF capacitor should improve nipple Although the LM3!7 is stable with no output capa- citance, like any feedback circuit, certain values of external capacitance can cause excessive ringing. An output capacitance (Co) in the form of a 1 pF tantalum or 25 pF aluminum electrolytic capacitor on the output swamps this effect and insures stability. PROTECTION DIODES . When extemal capacitors are used with any I.-C. re- gulator it is sometimes necessary to add protection diodes to prevent the capacitors from discharging through low current points into the regulator. Figure 18 shows the LM3i7 with the recommended protection diodes for output voltages in excess of 25 V or high capacitarice values (Co > 25 pF, Cap) > 10uF). Diode D, prevents Co from discharging thru the I.C. during an input short circuit. Diode D2 protects against capacitor Can discharging through the 1.C. during an output short circuit. The combination of diodes D, and Dz prevents Capy from discharging through the I.C. during an input short circuit. FIGURE 18 - VOLTAGE REGULATOR WITH PROTECTION DIODES inahe 1M317 = To be aa v0 2 me 1iaoas i Adj 2 > ow MEpStaza mm 4 Camtrel 4 Minty Voulet.23v D1 protects the device during an input short circult The LM317 is capable of providing extremely good load regulation, but a few precautions are needed to obtain the programming resistor (R\) should be connected as close to + maximum performance. For best performance, the tegulator as possible to minimize line drops which effectively appear in series with the reference, thereby degrading regulation . The ground end of R, can be returned near the load ground to provide remote ground sensing and improve load regulation. 2-35FO Merion LM317 3-Terminal Adjustable Output Positive Voltage Regulators FIGURE 19-"LABORATORYPOWER SUPPLY WITH ADJUSTABLE CURRENT LIMIT AND OUTPUT VOLTAGE De 44 1N4002 lo Vi . Vout Vin2 VYout2 7 LM317 MAA LM317 a 32V to 40V Ld DS ar 240 HINAOOL O.1uF T dust. 1 D1 Adjust 2 = = AGNe INA001 Say Voltage =p 10uP 1K 1N4001 Adjust Current D2 Lheut Adjust Qt = 2nge22 Diode D1 and D2 and transistor QZ OUTPUT RANGE are added to allow adjustment O<loc1.2a 2 3 of output voltage lo 0 volts. -10V g 2nse40 D Protects both LML17's during an input short circuit, 10 FIGURE 20-ADJUSTABLE CURRENT FIGURE 21-5V ELECTRONIC SHUT DOWN LIMITER REGULATOR DL 4 Vin Lai? Vout Ri to ~ +26V 125 IN4002 1 vin 1M317 ae (Vs Re AN4O01 I ____ DS 1ae To provide current limited of to yptoor 120 aE 14001 to the system ground.the source of the FET must be tired to a negative Adjust 2 = voltage below=1.25V ans860 Rap Neel SK MpS2222 Y Control pe deet jomax+ins Var Minimum Vout=1.25V VoxBVnm <1o<1.54 > Hminaioes<loxt GA D1 protects the device during an input short circuit FIGURE 22-SLOW TURN-ON REGULATOR FIGURE 23-CURRENT REGULATOR ve LM317 o va s 2405 gy | EANAOOL MA- Adjust 5K S77 MPS2907 1 ar 10HF Vin LM317 Vout Ri dea Adjuat bow a, four YE) otans i.25V oR 2OMASIOULCI.SA 2-36