PA iis LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator DESCRIPTION he LT1083 series of positive adjustable regulators T: designed to provide 7.5A, 5A and 3A with higher efficiency than currently available devices. All internal circuitry is designed to operate downto 1V input-to-output differential and the dropout voltage is fully specified as a- function of load current Dropout is guaranteed ata maximum of 1.5Vat maximum output current, decreasing at lower trimming adjusts the reference voltage to 1%. Current load currents. On-chip limit is also trimmed, minimizing the stress on both the ) regulator and power source circuitry under overland conditions. The LT1083/LT1084/LT1085 devices are pin compatible with older three-terminal regulators A 10. F output capacitor is required on these new devices. However, this is included in most regulator designs. Unlike PNP regulators, where up to 10% of the output current is wasted as quiescent current the LT1083 quiescent current flows into the load, increasing efficiency. Fixed Versions Available (FEATURES ) Three- Terminal Adjustable * Output Current of 3A4,5A7.5A e Operates Down to 1V Dropout e Guaranteed Dropout Voltage at Multiple Current Levels e Line Regulation: 0.015% e Load Regulation: 0.01% 100% Thermal Limit Functional Test (APPLICATIONS High Efficiency Linear Regulators e Post Regulators for Switching Supplies Constant Current Regulators e Battery Chargers DEVICE OUTPUT CURRENT* LT1083 7.5A LT1084 5.0A LT1085 3.0A (PACKAGE/ ORDER INFORMATION 3-9LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator o (ABSOLUTE MAXIMUM RATINGS ) Power Dissipation 000.0... sess Internally limited MM " Grades : Control Section .......0-cese 55% to 150% Input-to-Output Voltage Differential Power Transistor .................. 55% to 2007 Storage Temperature Range... 65% to 150% Lead Temperature (Soldering, 10 Set)... sesesssssessees 300%c Operating Junction Temperature Range (PRECONDITIONING ) " C'" Grades: Control Section 0.2.0... Oe to 125% 100 % thermal shutdown functional test Power Transistor 2.0... O% to 150% | "I" Grades : Control Section .......c.ccs 40% to 125% Power Transistor ................ 40% to 150% (TYPICAL APPLICATION ) SY,7,.5A Regulator Dropout Voltage vs Output Current 2 Vow 26.5V IN LT1083 OUT 8V AT 7.5A ADJ 5 J . 2 LOur LOMF # | TANTALUM 3 *REQUIRED FOR STABILITY 0 & 6 Ira Loa OUTPUT CURRENT (ELECTRICAL CHARACTERISTICS Reference Voltage | lour=100mA, T)*25 1.238 1.250 1.262 V ( VorVour) = 3V 10mA s Tour = Irvin voap 1.225 1.250 1.270 Vv LSVs ( VneVour) s 25V (Notes 3, 5, 6} e Line Regulation Troan = 10mA, 1.5Vs (VorVour) s15V, 12=25 T (Notes | @ 0.015 0.2 % 1,2) : e 0.035 02 % M Grades: 15Vs (VorVout) = 35 (Notes 1,2) 0.05 0.5 % C, [Grades : 15V = (VorVour) = 30V (Notes 1,2) e 0.05 0.5 % 3-10io LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator E' CTERISTICS LECTRICAL CHARA Load Regulation (Vin-Vout ) = 3V 10mA s Iours InntLoap T=25% (Notes 1,2,3,5 } e 0.1 0.3 % 0.2 04 % Dropout Voltage A Vrer=1%, lour=Irutt toa (Notes 4,5,7) e 1.3.1.5 Vv Current Limit LT1083 (Vin-Vour &5V e 8.0 9.5 A (Vm-Vour = 25V e 0.4 1.0 A LT1084 (Vi-Vout = 5V e (55 65 A (Vin- Vout =25V @ 103 0.6 A LT1085 (Vin-Vour 5V e 3.2 4.0 A | (neVour F25V e /02 05 A Minimum Load Current (Vin-Vour =25V e $ 10 mA Thermal Regulation Ta=25C, 30ms Pulse LT1083 0.002 0.010 iW LT1084 0.003 0.015 IW LT1085 0.004 0.020 % IW Ripple Rejection f= 120 Hz Cap =25y F,Cour =25u, F Tantalum lour=Jrutt Loan , (Vin - Vour) = 3V (Notes 5.6.7} e 60 75 dB Adjust Pin Current T)=25 C 55 HA e 120 LA Adjust Pin Current Change JOmAS lout Slut Loap L.5V_$(Vin-Vour) S 25V (Note 5) e 02 5 we Temperature Stability e 0.5 %, Long Term Stability T,=125 C, 1000 Hrs 0.3 1 % RMS Output Noise (% of Your} Ta=25 C l0Hz= sf < 10KHz 0.003 % Thermal Resistance Junction-to- Control Circuitry/Power Transistor Case LT1084 Z,M Package 0.65/2.7 Ciw LT1085 ZM: Packages . 0.7/3.0 Cr The @ denotes the specifications which apply over the full The Inn. toap curve is defined as the minimum value of operating temperature range. Note 1: See thermal regulator specification for change in output voltage due to heating effects Load and line regulation are measured sat a cycle pulse testing. constant junction temperature by low duty Note 2: Line and load regulation are guaranteed up to the Maximum power dissipation (60W for LT1083,30W for the LT1084(Z) and 30W for the LT1085). Power dissipation is determined by the input /output differential and output current. Guaranteed maximum power dissipation will not be available over the full input /output voltage range. Note 3: Inui oan is defined in the current limit curves current limit as a function of input to output voltage. Note that 60W power dissipation for the LT1083 ( 30W for the LT1084 (Z), 30W for the LT1085) is only achievable over a limited range of input - to- output voltage. Note 4:Dropout voltage is specified over the full output current range of the device. Test points and "limits are shown on. the Dropout Voltage curve. Note 5: For LT1083 Init roan is SA for -SSeu = Ti40T and 7.5A for T)z 40. Note 6: 1.7V (Vin-Vour)s 25V for TD62084 s40t. at -550 sT) Note 7:Dropout is 1.7V maximum for TD62084 at -55 < T; s40. 3-11FE de oricniscs LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator TYPICAL PERFORMANCE CHARACTERISTICS LT1083 Dropout Voitage @ INDICATES GUARANTEED TEST POINT 740" CeTI 5 150C MINIMUMINPUT/OUTPUT DIFFERENTIAL(Y} - ~ o 123 4 $ 47 8 10 OUTPUT CURRENT(A) ADJ G01 LT1084 Dropout Voltage oo @ INDICATES CUARANTEED TEST POINT w~hS Cals c150C Tcxnx12sc MINIMUMINPUT/OUTPUT DIFFERENTIAL(V) OUTPUT CURRENT(A) ADJ G04 LT1085 Dropout Voltage n INDICATES ~55*OeT5 150C O CeTs 5 128C 1 2 3 OUTPUT CURRENT(A) MINIMUMINPUT/OQUTPUT DIFFERENTUL(Y} ADJ G07 LT1083 Short-Circut Current o o & B * SHORT-CIRCUIT CURRENT(A) to 5 10 15 20 25 a0 (35 INPUT/OUTPUT DIFFERENTIAL(V} ADJ G02 LT1084 Short-Circut Current S SHORT-CIRCUIT CURRENT{A) oe, NOW & FON OG 5 10 15 2 2 Bw 35 INPUT/OUTPUT DIFFERENTIAL(V) 2 ADJ G05 LT1085 Short-Circut Current 6 SHORT-CIRCUIT CURRENT(A) - a oa 20 2 30 35 5 10 iS INPUT/OUTPUT DIFFERENTIAL(V) ADJ G08 LT1083 Load Regulation o.1 4n7.5a & 5 0.05 E Bo a & -0.05 9-0. 3 = -0.10 5 a & ~0.15 o -0.20 ~50-25 0 25 SO 78 100 128 18 TEMPERATURE(C) ADJ G03 LT1084 Load Regulation 0.10 g B 0.08 Ee s zB 0 a g & E 0.10 5 E-o15 o 0.20 -60-28 0 25 50 75 100 125 150 TEMPERATURE(C) ADJ G06 LT1085 Load Regulation ~ oieGa x g = 3 & a i~] o = = E c -50-25 0 25 80 78 100 125 150 TEMPERATURE(* C) ADJ GOS 3-12io L1T1083/LT1084/LT1085 7.5A, SA, 3A I AU Om arate C Ciel om courr lily TYPICAL PERFORMANCE CHARACTERISTICS Minimum Operating Current S ADJ G10 = Es Es Ey 8 o 8 Es a, & fog 2 3 2 Zz 1 = 5B 10 18 20 28 30 INPUT/OUTPUT DIFFERENTIAL(V) LT1083 Ripple Rejection {Vm -Vour) 2V RIPPLE. REJECTION(dB) ~- 58888 8sBBE FREQUENCY(Hz) ADJ G13 LT1084 Ripple Rejection i 90 80 7 60 50 40 30 APPLE = RIPPLE. REJECTION(dB) 10 100 1K 10K 100K FREQUENCY(Hz) ADJ G16 o 100 1K 10K 100K RIPPLE REJECTION(dB) RIPPLE REJECTION(d3) REFERENCE VOLTACE(V) Temperature Stability 1.27 1.25 1.24 1.23 -$0 -25 0 25 50 75 100 125 150 TEMPERATURE(C) ADJ G11 LT1083 Ripple Rejection vs Current 100 [R=120H2 so V RIPPLE = Vp-p 80 t . 70 {R=20KHz VRPPLE < 0.5Vp-p 0 50 40 _ 30 V our =5V 20 F~ Cap w25yF 10 LL Cour=26uF 0 1 2 3 4 5 6 7 6 OUTPUT CURRENT(A) ADJ G14 LT1084 Ripple Rejection vs Current 100 90 1R=120Hz VRIPPLE < 3Vp~p a0 t= 20KHz ~ V RIPPLE = 60 50 40 30 | vour =v 20 cans w25ur 10 |. Cour = 2567. o o OS 10 186 20 OUTPUT CURRENT(A) 25 3.0 AOS G17 ADJUST PIN CURRENT(#A) POWER(W) POWER() Adjust Pin Current 1 90 80 7 60 50 40 30 20 10 0 -80-25 0 2 80 75 100 125 150 TEMPERATURE( C) ADJ G12 LT1083 Maximum Power Dissipation" 90 60 70 60 50 40 30 20 10 Q 50 66 70 80 80 100 110120130 140 180 CASE TENPERATURE(*C) AS LINITED BY MAXINUM JUNCTION TEMPERATURE ADJ G15 LT1084 Maximum Power Dissipation 60 50 40 30 LT10842 20 10 50 80 70 80 go 100 110 120 190 140150 . CASE TEMPERATURE( C} AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE ADJ G18 3-13OUTPUT VOLTAGE INPUT DEVIATION(V) FM icc LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator TYPICAL PERFORMANCE CHARACTERISTICS LT1085 Ripple Rejection 100 90 ROPLE 80 7 60 30 40 (V Your) 2Vororour 30 20 10 Q RIPPLE REJECTION(dB) 100 10K 100K FREQUENCY(Hz) ADJ G19 LM1083 Load Transient Response 2 e nun + Oo DEVIATION(V) Cot = uF CouT 1047 TANTALUM o Your =10 VIN #13V PRELOAD= LOAD CURRENT(A) ena @ 50 TDE(S) ADJ G22 LM1083 Line Transient Response 150 - 100 60 8 Can! 20 Vour <10V Un =0.24 Gin = KF TANTALUM =10uF TANTALUM 100 TIME(S) 200 ADJ G25 OUTPUT YOLTACE DEVIATION(Y) LOAD CURRENT(A) OUTPUT VOLTAGE INPUT LT1085 Ripple Rejuction vs Current 100 - 1Rw120H2 90 V RIPPLE << 3p-p 80 a tr=20KHz yz 70 VRPPLE =< 0.5Vp-p F a0 B50 B40 3 30 & Vout =5V @ 205 cy =2sur 10 | Cour =25uF * i | o O08 10 16 20 28 3.0 OUTPUT CURRENT(A) ADJ G20 LM1083 Load Transient Response LM1084 Cin @ HP Cour =1Q2F Vour = 10V Vor = 13V PRELOAD= TIME(#S) 1 ADS G23 Line Transient Response ee oa ao 60 , . DEVITION() DEVIATION(Y) Vout =10V Lin $0.24 Cin 1eF TANTALUM Cour =#10uF TANTALUM 106 TIME(i&) 200 ADJ G26 LM1085 Maximum Power Dissipation 50 40 30 LTIOBSCT POWER() 20 60 70 80 90 100 110120 130 140150 . CASE TEMPERATURE{ C) AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE ADJ G21 LM1083 Load Transient Response 0.3 Ee az 3 0.1 3 & 2 8 5 a = B= BE & 2 - 8 1 g % 50 100 TIME(uS) ADJ G24 LM1085 Line Transient Response Gl a 60 2. 7 TTT BS gf Po cam oor Oo bE A \ & s B -20 aa" ~40 v =10 5 mecoge | tL = 14 Chr a IMF TANTALUM E Court 104F TANTALUM bE 13 ae 114 4 % [|| 100 200 . TINE(##S) ADJ G27 3-14LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator (BLOCK DIAGRAM & THERMAL LIMIT 7* | ran Las AAA WA Vapi Vour 1083/4/5 ADJ BD The LT1083 family of three-terminal adjustable regulators is easy to use and has all the protection features that are expected in high performance voltage regulators. They are short-circuit protected, and have safe area protection as well es thermal shutdown to tum off the regulator should the junction temperature exceed about 165%. These regulators are pin compatible with older three- terminal adjustable devices, offer lower dropout voltage and More precise reference tolerance. Further, the reference stability with temperature is improved over older types of regulators. The only circuit difference between using the LT1083 family and older regulators is that this new family requires an output capacitor for stability. smaller than this can be used with the LT1083. Many different types of capacitors with widely varying characteristics are available. These capacitors differ in capacitor tolerance (sometimes ranging up to + 100% ), equivalent series resistance , and capacitance temperature coefficient. The 150, F or 22y F values given will ensure stability. When the adjustment terminal is bypassed to improve the ripple rejection , the requirement for an output capacitor increases. The value of 22 yF tantalum or 150 uF aluminum covers all cases of bypassing the adjustment terminal. Without bypassing the adjustment terminal, smaller capacitors can be used with equally good results and the table below shows approximately what size STABILITY ) are needed to ensure stability. P The circuit design used in the LT1083 family requires the use of an output capacitor as part of the device frequency compensation. For all operating conditions, the addition of 150, F aluminum electrolytic ora 22y F solid tantalum on the output will ensure stability. Normally, capacitors much RECOMMENDED CAPACITOR VALUES ) INPUT OUTPUT ADJUSTME NT 10. F 10, F Tantalum,50,. F Aluminum None 10, F 55, F Tantalum,150. F Aluminum 20, F 3-15 o (APPLICATIONS INFORMATION ) Normally, capacitor values on the order of 100, F are used in the output of many regulators to ensure good transient response with heavy load current changes. Output capacitance can be increased without limit and larger values of output capacitor further improve stability and transient response of the LT 1083 regulators. Another possible stability problem that can occur in monolithic IC regulators is current limit oscillations. These can occur because , in current limit, the safe area protection exhibits a negative impedance. The safe area protection decreases the current limit as the input-to- output voltage increases. That is the equivalent of having a negative resistance since increasing voltage causes current to decrease. Negative resistance during current limit is not unique to the LT1083 series and has been present on all power IC regulators. The value of the negative resistance is a function of how fast the current limit is folded back as input-to-output voltage increases . This negative resistance can react with capacitors or inductors on the input to cause oscillation during current limiting. Depending on the value of series resistance, the overall circuitry may end up unstable . Since this is a system problem , it is not necessarily easy to solve; however, it dose not cause any problems with the IC regulator and usually be ignored. L1T1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator (PROTECTION DIODES ) In normal operation, the LT1083 family does not need any protection diodes. Older adjustable regulators Tequired protection diodes between the adjustment pin and the output and from the output to the input to prevent over stressing the die. The internal current paths on the LT1083 adjustment pin re limited by internal tesistors. Therefore,even with capacitors on the adjustment pin, no protection diode is needed to ensure device safety under short-circuit conditions. Diodes between input . and output are usually not needed. The internal diode between the input and the output pins of the LT1083 family can handle microsecond surge currents of 50A to 100A. Even with large output capacitances, it is very difficult to get those values of. surge currents in normal operations. Only with a high value of output capacitors,such as 1000, F to 5000, F instantaneously shorted to ground ,can damage occur. A crowbar circuit at the input of the LT1083 can generate those kinds of currents, and a diode from output to input is then recomimended . Normal power supply cycling or and with the input pin even plugging and unplugging in the system will not generate current large enough to do any damage. The adjustment pin can be driven on a transient basis + 25V, with respect tothe output without any device degradation. Of exceeding the maximum input differential cause the internal transistors to break down and none of the protection circuitry is functional. course, as with any IC regulator, to output voltage DL 1N4002 (OPTIONAL) v7 Var IN LT1083 OUT ADJ - -4 = 4 Rly Cour 1504F +4 Cap Ts R2 tK) ADJ Foo 3-16oo a OVERLOAD RECOVERY Like any of the IC power regulators , the LT1083 has safe area protection. The safe area protection decreases the current limit as input-to-output voltage increase and keeps the power transistor inside a safe operating region for all values of input-to-output voltage. The LT1083 protection is designed to provide some output current at all values of input-to-output voltage upto the device breakdown. When power is first tumed on , as the input voltage rises, the output follows the input, allowing the regulator to start up into very heavy loads. During the start-up , as the input voltage is rising, the input-to-output voltage differential remains small, allowing the regulatorto supply large output currents. With high input voltage, a problem can occur wherein removal of an output short will not allow the output voltage to recover. Older regulators , such as the HB7800 series, also exhibited this phenomenon, so it is not unique to the LT1083. (APPLICATIONS INFORMATION ) The problem occurs with a heavy output load when the input voltage is high and the output voltage is low, such as immediately after removal of a short. The load line for such a load may intersect the output current curve at two points.If this happens , there are two stable output operating points for the regulator. With this double intersection , the power supply may need to be cycled down to ero and brought up again to make the output recover, (RIPPLE REJECTION ) The typical curves for ripple rejection reflect values for a bypassed adjustment pin. This curve will be trae for all values of output voltage. For proper bypassing and ripple rejection approaching the values shown, the impedance of the adjust pin capacitor at the ripple frequency should be less than the value of RJ, (normally 100 to 12002). The size of the required adjust pin capacitor is a function of the input ripple frequency. LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator At 120Hz the adjust pin capacitor should be 25, F if Ri=100Q . At 10KHz only 0.22, F is needed. For circuits without an adjust pin bypass capacitor, the ripple rejection will bea functionon of output voltage. The output ripple will increase directly asa ratio of the output voltage to the reference voltage (Vour/Vrezr ). For example, with the output voltage equal toSV and no adjust pin capacitor, the output ripple will be higher by the ratio of 5V/1.25V or four times large. Ripple rejection will be de-graded by 12dB from the value shown on the typical curve. OUTPUT VOLTAGE The LT1083 develops a 1.25V reference voltage between the output and the adjust terminal (see Figure 1). By placing aresistor RI between these two terminals , a constant current is caused to flow through RI and down through R2 to set the overall output voltage. Normally this current is the specified minimum load current of 10mA.Because Ip; is very small and constant when compared with the current through R1, it irepresents a small error and can usually be ignored. Voy IN| LT1083 OUT ADJ + 10MF yO | 504F F Vour =Vrer (1+ 22) iR2 ADJ For FIGURE 1.BASIC ADJUSTABLE REGULATORio LOAD REGULATION Because the LT1083 is a three-terminal device , it is not possible to provide te remote load sensing . Load regulation will be limited by the resistance of the wire connecting the regulator to the load. The data sheet specification for load regulation is measured at the bottom of the package. Negative side sensing is a tme Kelvin connection, with the bottom of the output divider returned to the negative side of the load. Although it may not be immediately obvious , best load regulation is obtained when the top of the resistor divider R1 is connected directly to the case not to the load. This is illustrated in Figure 2 . If R1 were connected to the load, the effective resistance between the regulator and the load would be: Rr PARASITIC LINE RESISTANCE Vit meJIN LTI083 OUT ADJ Ru CONNECT Ri TO CASE CONNECT R2 TO LOAD ADJ F02 FIGURE 2.CONNECTIONS FOR BEST LOAD . REGULATION (APPLICATIONS INFORMATION ) Connected as shown Rp is not multiplied by the drivider radio. Rp is about 0.004 per foot using 16-gauge: wire. This translates to 4mV/ft at 1A load current, soit is important to keep the positive lead between regulator and load as short as possible and use large wire or PC board traces. (THERMAL CONSIDERATION ) The LT1083 series of regulators have internal power and thermal limited circuitry designed to protect the device LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator under overload conditions . For continuous normal Joad conditions however, maximum junction temperature ratings must not be exceed . It is important to give careful consideration to all sources of thermal resistance from junction to ambient. This includes junction-to-case. case-to- heat sink interface,and heat sink resistance itself, New thermal resistance specifications have been developed to more accurately reflect device temperature and ensure safe operating temperatures. The data section for these new regulators provides a separate thermal resistance and maximum junction temperature for both the Contro! Section and the Power Transistor. Previous regulators, with thermal an average of @ single junction-to - case resistance specification, used provided here and therefore could allow excessive two values junction temperatures under certain conditions of ambient temperature and heat sink resistance . To avoide this possibility , calculations should be made for both sections toensure that both thermal limits are met. Junction-to-case thermal resistance is specified from the IC junction to the bottom of the case directly below the die.This is the lowest resistance path for heat flow. Proper mounting is required to ensure the best possible thermal flow from this area of the package to the heat sink. Thermal compound at the case-to-heat sink interface is strongly recommended . If the case of the device must be electrically isolated , a thermally conductive spacer can be used, as long as its added contribution to thermal resistance is considered. Note that the case of all devices in this series is electrically connected to the output. 3-18L1T1083/LT1084/LT1085 7.5A, 5A, 3A TO eK R th eCRely om Cranley o For example,using an LT1083 (TO-3P, Commercial) and assuming: Vy (max continuous) =9V, Vour=5V, lour=6A, Tr=75C , @ weatsox =1C/W 6 case-rongat smx 70.2C /W for K package with thermal compound. Power dissipation under these conditions is equal to: Pp=(Var Vour)(lour)=24W Junction temperaure will be equal to:Ts=Ts+Pp (6 Heat sIxK+ CASE-TOHEAT SINK*@ sc) For the Control Section: T=75 t +24W(1 C/W+0.2T (M10.6C/W)IEHI8T 118T <150T =Trax(Power Transistor Commercial Range) For the Power Transistor: TJ=75 +24W(1 C /W+0.2 /(M+1.6 /W)=142 142% <150 =Tpvax(Power Transistor Commercial Range) In both cases the junction temperature is below the maximum rating for the respective sections, ensuring reliable operation. {TYPICAL APPLICATIONS ) 7.5Variable Regulator Tl C30B TRIAD LoimH | OV TO 35V LN IN LT1083 OUT CA TO 7.5A F-269U J > 202 3 becouse ADL 3240 1 irio04-12l L 11OVAC vac} =s/( = 1N4003 = = < ~ 20> om) in914 ox 7 pie ea T = | SOUTPUT 3 C30B + 2 16K" 4 FP < T seo 18V0 31K" > > 10K t r i < S$ 10K * 1% FILM RESISTOR L:DALE TO-5 TYPE T2; STANCOR 11Z-2003 GENERAL PURPOSE REGULATOR WITH SCR PREREGULATOR TO LOWER POWER DISSIPATION. ABOUT 1.7V DIFFERENTIAL IS MAINTAINED ACROSS THE LT1083 INDEPENDENT OF OUTPUT ADJ TALO VOLTAGE AND LOAD CURRENT 3-19LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator Semiconductor PARALLELING REGULATORS 2 FEET #18 WIRE Vin IN LT1083 OUT} ADJ Vour =1,28V(1+82) lovr=0A TO 15A 0.0162 IN LT1083 OUT "THE #18 WIRE ACTS ADJ 120 AS BALLAST RESISTANCE Ri INSURING CURRENT SHARING BETWEEN BOTH DEVICES 4 yRe 5 1083/4/5 ADJ TAQ3 IMPROVING RIPPLE REJECTION Vx pJIN T1083 OUT Vour 1 [Lee ey < + > at 1OuF Ize sour TL +[ C 365 = ap Sur R2 1% *C} IMPROVES RIPPLE REJECTION Xe SHOULD BE<R1 AT RIPPLE FREQUENCY 1083/4/5 ADJ TA04 REMOTE SENSING R DROP 300mV von IN LT1083 OUT (MAX DROP 300mV) var Vv ADJ 5 + =~ 10uF RETURN RETURN 1083/4/5 ADJ TAGS 3-20LT1083/LT1084/LT1085 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulator HIGH EFFICIENCY REGULATOR WITH SWITCHING PREREGULATOR imH Vin A IN LT1083 OUT Vour 28V 10 , Apt : 240 + ADJ TA06 1.2V TO 15V ADJUSTABLE REGULATOR 5V REGULATOR WITH SHUTDOWN * Vor 26.59 IN LT1083 OUT Vour ADJ " | , Vox IN LT1083 OUT +(C1 90.9. +4 C2 10uF 100uF ADJ Pre 4 1K Vour Sv ~ 10ur = = am me hk 100MF " NEEDED IF DEVICES IS FAR FROM FILTER CAPACITORS * Vour=1.25v(1+ 82) me . => OUTPUT SHUTS DOWN TO 1.3V ADJTAO7 ADJ TAB AUTOMATIC LIGHT CONTROL PROTECTED HIGH CURRENT LAMP DRIVER 12V 5A IN 1T1083 our <D isv TTL LOAD ADJ CMOS Vin IN LT1083 OUT ADJ + L ADJ TA09 ADI TAI0 3-21