LT1086 Series 1.5A Low Dropout Positive Regulators Adjustable and Fixed 2.85V, 3.3V, 3.6V, 5V, 12V FEATURES DESCRIPTIOU n 3-Terminal Adjustable or Fixed The LT®1086 is designed to provide up to 1.5A output 2.85V, 3.3V, 3.6V, 5V, 12V current. All internal circuitry is designed to operate down n Output Current of 1.5A (0.5A for LT1086H) to 1V input-to-output differential and the dropout voltage n Operates Down to 1V Dropout is fully specified as a function of load current. Dropout is n Guaranteed Dropout Voltage at Multiple Current Levels guaranteed at several operating points up to a maximum n Line Regulation: 0.015% of 1.5V at maximum output current. Dropout decreases at n Load Regulation: 0.1% lower load currents. On-chip trimming adjusts the refer- n 100% Thermal Limit Functional Test ence/ouput voltage to 1%. Current limit is also trimmed, n Ripple Rejection >75dB minimizing the stress on both the regulator and power n Available in 3-Pin TO-220 and 3-Pin DD Packages source circuitry under overload conditions. The LT1086 is pin compatible with older 3-terminal adjust- APPLICATIOU S able regulators. A minimum 10m F output capacitor is required on these devices. n SCSI-2 Active Terminator The LT1086 offers excellent line and load regulation speci- n High Efficiency Linear Regulators fications and ripple rejection exceeds 75dB even at the n Post Regulators for Switching Supplies maximum load current of 1.5A. The LT1086 is floating n Constant Current Regulators architecture with a composite NPN output stage. All of the n Battery Chargers quiescent current and the drive current for the output n Microprocessor Supply stage flows to the load increasing efficiency. The LT1086 is available in a 3-pin TO-220 package and a space-saving surface mountable 3-pin DD package. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIOU LT1086 Dropout Voltage 2 5V to 3.3V Regulator V) INDICATES GUARANTEED TEST POINT L ( A VIN ‡ 4.75V IN LT1086-3.3 OUT 3.3V AT 1.5A FFERENTI –505°°CC ££ TTJJ ££ 115205°°CC DI GND T U 10µF* 10µF TP 1 TANTALUM TANTALUM OU TJ = –55°C NPUT/ TTJJ == 21550°C°C M I LT1086 • TA01 U M NI *MAY BE OMITTED IF INPUT SUPPLY IS WELL MI BYPASSED WITHIN 2" OF THE LT1086 0 0 0.5 1 1.5 OUTPUT CURRENT (A) LT1086 • TA02 sn1086 1086ffs 1

LT1086 Series ABSOLUTE WMAXIWMUWM RATINUGS (Note 1) Power Dissipation...............................Internally Limited “M” Grades Input Voltage*......................................................... 30V Control Section .......................... –55(cid:176) C to 150(cid:176) C Operating Input Voltage Power Transistor........................ –55(cid:176) C to 200(cid:176) C Adjustable Devices........................................... 25V Storage Temperature Range.................–65(cid:176) C to 150(cid:176) C 2.85V Devices .................................................. 18V Lead Temperature (Soldering, 10 sec)..................300(cid:176) C 3.3V, 3.6V, and 5V Devices............................... 20V * Although the device’s maximum operating voltage is limited, (18V for a 12V Devices ...................................................... 25V 2.85V device, 20V for a 5V device, and 25V for adjustable and12V devices) the Operating Junction Temperature Range devices are guaranteed to withstand transient input voltages up to 30V. For “C” Grades input voltages greater than the maximum operating input voltage some Control Section ...............................0(cid:176) C to 125(cid:176) C degradation of specifications will occur. For fixed voltage devices operating at Power Transistor.............................0(cid:176) C to 150(cid:176) C input/output voltage differentials greater than 15V, a minimum external load of 5mA is required to maintain regulation. “I” Grades Control Section .......................... –40(cid:176) C to 125(cid:176) C PRECONUDITIONUINUG Power Transistor........................ –40(cid:176) C to 150(cid:176) C 100% Thermal Shutdown Functional Test. PACKAGE/ORDER IUNFORWMATIOUN ORDER FRONT VIEW ORDER BOTTOM VIEW PART NUMBER PART NUMBER 3 VIN ADJ TAB IS LT1086CH OUTPUT 2 VOUT LT1086CM 2 VIN 1 3 V(COAUSTE) LT1086MH 1 A(GDNJD)† LT1086CM-3.3 LT1086CM-3.6 M PACKAGE 3-LEAD PLASTIC DD LT1086IM H PACKAGE q JA = 30(cid:176)C/W** 3-LEAD TO-39 METAL CAN **WITH PACKAGE SOLDERED TO 0.5IN2 COPPER AREA LT1086IM-3.3 q JA = 150(cid:176)C/W OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. q JA CAN VARY FROM 20(cid:176)C/W TO >40(cid:176)C/W DEPENDING ON MOUNTING TECHNIQUE. ORDER ORDER PART NUMBER PART NUMBER BOTTOM VIEW VIN IS COAUSTEP UT LT1086CK FRONT VIEW LT1086CT LT1086CK-5 LT1086CT-2.85 2 3 VIN LT1086CK-12 TAB IS LT1086CT-3.3 OUTPUT 2 VOUT LT1086IK LT1086IT 1 1 ADJ LT1086IK-5 (GND)† LT1086IT-5 ADJ (GND)* T PACKAGE LT1086IK-12 3-LEAD PLASTIC TO-220 LT1086IT-12 K PACKAGE 2-LEAqDJ AT O= -335 M(cid:176)CE/TWAL CAN LT1086MK q JA = 50(cid:176)C/W LT1086CT-3.6 LT1086MK-5 LT1086CT-5 LT1086MK-12 LT1086CT-12 OBSOLETE PACKAGES Consider the T Package for Alternate Source †For fixed versions. Consult LTC Marketing for parts specified with wider operating temperature ranges. sn1086 1086ffs 2

LT1086 Series ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25(cid:176) C. A PARAMETER CONDITIONS MIN TYP MAX UNITS Reference Voltage LT1086, LT1086H I = 10mA, T = 25(cid:176) C, (V – V ) = 3V 1.238 1.250 1.262 V OUT J IN OUT (Note 3) 10mA £ I £ 1.5A, (0.5A for LT1086H), 1.5V £ (V – V ) £ 15V l 1.225 1.250 1.270 V OUT IN OUT Output Voltage LT1086-2.85 I = 0mA, T = 25(cid:176) C, V = 5V 2.82 2.85 2.88 V OUT J IN (Note 3) 0V £ I £ 1.5A, 4.35V £ V £ 18V l 2.79 2.85 2.91 V OUT IN LT1086-3.3 V = 5V, I = 0mA, T = 25(cid:176) C 3.267 3.300 3.333 V IN OUT J 4.75V £ V £ 18V, 0V £ I £ 1.5A l 3.235 3.300 3.365 V IN OUT LT1086-3.6 V = 5V, I = 0mA, T = 25(cid:176) C 3.564 3.600 3.636 V IN OUT J 5V £ V £ 18V, 0 £ I £ 1.5A l 3.500 3.672 V IN OUT 4.75V £ V £ 18V, 0 £ I £ 1A, T ‡ 0(cid:176) C 3.500 3.672 V IN OUT J V = 4.75V, I = 1.5A, T ‡ 0(cid:176) C 3.300 3.672 V IN OUT J LT1086-5 I = 0mA, T = 25(cid:176) C, V = 8V 4.950 5.000 5.050 V OUT J IN 0 £ I £ 1.5A, 6.5V £ V £ 20V l 4.900 5.000 5.100 V OUT IN LT1086-12 I = 0mA, T = 25(cid:176) C, V = 15V 11.880 12.000 12.120 V OUT J IN 0 £ I £ 1.5A, 13.5V £ V £ 25V l 11.760 12.000 12.240 V OUT IN Line Regulation LT1086, LT1086H I = 10mA, 1.5V £ (V – V ) £ 15V, T = 25(cid:176) C 0.015 0.2 % LOAD IN OUT J l 0.035 0.2 % LT1086-2.85 I = 0mA, T = 25(cid:176) C, 4.35V £ V £ 18V 0.3 6 mV OUT J IN l 0.6 6 mV LT1086-3.3 4.5V £ V £ 18V, I = 0mA, T = 25(cid:176) C 0.5 10 mV IN OUT J l 1.0 10 mV LT1086-3.6 4.75V £ V £ 18V, I = 0mA, T = 25(cid:176) C 0.5 10 mV IN OUT J l 1.0 10 mV LT1086-5 I = 0mA, T = 25(cid:176) C, 6.5V £ V £ 20V 0.5 10 mV OUT J IN l 1.0 10 mV LT1086-12 I = 0mA, T = 25(cid:176) C, 13.5V £ V £ 25V 1.0 25 mV OUT J IN l 2.0 25 mV Load Regulation LT1086, LT1086H (V – V ) = 3V, 10mA £ I £ 1.5A, (0.5A for LT1086H) IN OUT OUT T = 25(cid:176) C (Notes 2, 3) 0.1 0.3 % J l 0.2 0.4 % LT1086-2.85 V = 5V, 0 £ I £ 1.5A, T = 25(cid:176) C (Notes 2, 3) 3 12 mV IN OUT J l 6 20 mV LT1086-3.3 V = 5V, 0 £ I £ 1.5A, T = 25(cid:176) C (Notes 2, 3) 3 15 mV IN OUT J l 7 25 mV LT1086-3.6 V = 5.25V, 0 £ I £ 1.5A, T = 25(cid:176) C (Notes 2, 3) 3 15 mV IN OUT J l 6 25 mV V = 5V, 0 £ I £ 1A, T = 25(cid:176) C 2 15 mV IN OUT J l 4 25 mV LT1086-5 V = 8V, 0 £ I £ 1.5A,T = 25(cid:176) C (Notes 2, 3) 5 20 mV IN OUT J l 10 35 mV LT1086-12 V = 15V, 0 £ I £ 1.5A,T = 25(cid:176) C (Notes 2, 3) 12 36 mV IN OUT J l 24 72 mV Dropout Voltage LT1086/-2.85/-3.3/-3.6/-5/-12 D V , D V = 1%, I = 1.5A (Note 4) l 1.3 1.5 V OUT REF OUT (V – V ) IN OUT LT1086H D V = 1%, I = 0.5A (Note 4) l 0.95 1.25 V REF OUT sn1086 1086ffs 3

LT1086 Series ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25(cid:176) C. A PARAMETER CONDITIONS MIN TYP MAX UNITS Current Limit LT1086/-2.85/-3.3/-3.6/-5/-12 (V – V ) = 5V l 1.50 2.00 A IN OUT (V – V ) = 25V l 0.05 0.15 A IN OUT LT1086H (V – V ) = 5V l 0.50 0.700 A IN OUT (V – V ) = 25V l 0.02 0.075 A IN OUT Minimum Load Current LT1086/LT1086H (V – V ) = 25V (Note 5) l 5 10 mA IN OUT Quiescient Current LT1086-2.85 V £ 18V l 5 10 mA IN LT1086-3.3 V £ 18V l 5 10 mA IN LT1086-3.6 V £ 18V l 5 10 mA IN LT1086-5 V £ 20V l 5 10 mA IN LT1086-12 V £ 25V l 5 10 mA IN Thermal Regulation T = 25(cid:176) C, 30ms pulse 0.008 0.04 %/W A Ripple Rejection f = 120Hz, C = 25m F Tantalum, I = 1.5A, (I = 0.5A for LT1086H) OUT OUT OUT LT1086, LT1086H C = 25m F, (V – V ) = 3V l 60 75 dB ADJ IN OUT LT1086-2.85 V = 6V l 60 72 dB IN LT1086-3.3 V = 6.3V l 60 72 dB IN LT1086-3.6 V = 6.6V l 60 72 dB IN LT1086-5 V = 8V l 60 68 dB IN LT1083-12 V = 15V l 54 60 dB IN Adjust Pin Current LT1086, LT1086H T = 25(cid:176) C 55 m A J l 120 m A Adjust Pin Current LT1086, LT1086H 10mA £ I £ 1.5A (0.5A for LT1086H) OUT Change 1.5V £ (V – V ) £ 15V l 0.2 5 m A IN OUT Temperature Stability l 0.5 % Long-Term Stability T = 125(cid:176) C, 1000 Hrs. 0.3 1 % A RMS Output Noise T = 25(cid:176) C, 10Hz = £ f £ 10kHz 0.003 % A (% of V ) OUT Thermal Resistance H Package: Control Circuitry/Power Transistor 15/20 (cid:176) C/W Junction-to-Case K Package: Control Circuitry/Power Transistor 1.7/4.0 (cid:176) C/W M Package: Control Circuitry/Power Transistor 1.5/4.0 (cid:176) C/W T Package: Control Circuitry/Power Transistor 1.5/4.0 (cid:176) C/W Note 1: Absolute Maximum Ratings are those values beyond which the life of by the input/output differential and the output current. Guaranteed a device may be impaired. maximum power dissipation will not be available over the full input/output Note 2: See Thermal Regulation specifications for changes in output range. See Short-Circuit Current curve for available output current. voltage due to heating effects. Line and load regulation are measured at a Note 4: Dropout voltage is specified over the full output current range of constant junction temperature by low duty cycle pulse testing. Load the device. Test points and limits are shown on the Dropout Voltage curve. regulation is measured at the output lead » 1/8" from the package. Note 5: Minimum load current is defined as the minimum output current Note 3: Line and load regulation are guaranteed up to the maximum power required to maintain regulation. At 25V input/output differential the device dissipation of 15W (3W for the LT1086H). Power dissipation is determined is guaranteed to regulate if the output current is greater than 10mA. sn1086 1086ffs 4

LT1086 Series TYPICAL PERFORWMANUCE CHARACTERISTICS Minimum Operating Current LT1086 Short-Circuit Current LT1086 Load Regulation (Adjustable Device) 2.5 0.10 10 TJ = 150°C %) 0.05 D I = 1.5A mA) 9 CURRENT (A) 12..50 TTJJ == 2–55°5C°C DEVIATION ( 0 G CURRENT ( 678 SHORT-CIRCUIT 01..50 GUARANTEED OUTPUT VOLTAGE –––000...011550 NIMUM OPERATIN 3452 TTJJT J== =–1 525055°°°CCC OUTPUT CURRENT MI 1 0 –0.20 0 0 5 10 15 20 25 30 –50 –25 0 25 50 75 100 125 150 0 5 10 15 20 25 30 35 INPUT/OUTPUT DIFFERENTIAL (V) TEMPERATURE (°C) INPUT/OUTPUT DIFFERENTIAL (V) LT1086 • TPC01 LT1086 • TPC02 LT1086 • TPC03 LT1086 Maximum Power Temperature Stability Adjust Pin Current Dissipation* 2 100 20 90 VOLTAGE CHANGE (%) 01 mT PIN CURRENT (A) 6457800000 POWER (W) 1150 LLTT11008866CMKLKT1086CT UTPUT –1 ADJUS 3200 5 O 10 –2 0 0 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 50 60 70 80 90 100110120130140150 TEMPERATURE (°C) TEMPERATURE (°C) CASE TEMPERATURE (°C) *AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE LT1086 • TPC04 LT1086 • TPC05 LT1086 • TPC06 LT1086 Ripple Rejection LT1086 Ripple Rejection vs Current LT1086-5 Ripple Rejection 100 100 80 90 VRIPPLE £ 3VP-P VRIPPLE £ 0.5VP-P 90 VfRR =IP P1L2E0 H£ z 3VP-P 70 VRIPPLE £ 3VP-P VRIPPLE £ 0.5VP-P 80 80 (VIN – VOUT) ‡ 3V N (dB) 70 (VIN – VOUT) ‡ 3V N (dB) 70 VfRR =IP P2L0Ek H£ z 0.5VP-P N (dB) 5600 PPLE REJECTIO 45630000 (VIN – VOUT) ‡ VDROPOUT PPLE REJECTIO 46350000 PPLE REJECTIO 4300 (VIN – VOUT) ‡ VDROPOUT RI RI RI 20 2100 CCIOAAUDDTJJ === 122.0550mAmF FA ATT F RFREEQQUUEENNCCIEIESS > < 6 600HHzz 2100 VCCOAODUUJTT === 2525V5mm FF 10 IOUT = 1.5A 0 0 0 10 100 1k 10k 100k 0 0.25 0.5 0.75 1.0 1.25 1.5 10 100 1k 10k 100k FREQUENCY (Hz) OUTPUT CURRENT (A) FREQUENCY (Hz) LT1086 • TPC07 LT1086 • TPC08 LT1086 • TPC09 sn1086 1086ffs 5

LT1086 Series TYPICAL PERFORWMANUCE CHARACTERISTICS LT1086-5 Ripple Rejection LT1086-12 Ripple Rejection vs Current LT1086-12 Ripple Rejection vs Current 100 80 VRIPPLE £ 3VP-P VRIPPLE £ 0.5VP-P 100 90 70 90 RIPPLE REJECTION (dB) 467835000000 VVffRRRR ==IIPP PP12LL20EE0k HH££ zz 30V.5PV-PP-P RIPPLE REJECTION (dB) 2456300000 (VIN – VOUT) ‡ VDROP(VOIUNT – VOUT) ‡ 3V RIPPLE REJECTION (dB) 467835000000 VVffRRRR ==IIPP PP12LL20EE0k HH££ zz 30V.5PV-PP-P 2100 VCCOAODUUJTT === 2525V5mm FF 10 IOUT = 1.5A 2100 VCCOAODUUJTT === 2525V5mm FF 0 0 0 0 0.25 0.5 0.75 1.0 1.25 1.5 10 100 1k 10k 100k 0 0.25 0.5 0.75 1.0 1.25 1.5 OUTPUT CURRENT (A) FREQUENCY (Hz) OUTPUT CURRENT (A) LT1086 • TPC10 LT1086 • TPC11 LT1086 • TPC12 LT1086 Line Transient Response LT1086 Load Transient Response LT1086H Short-Circuit Current 60 0.3 1.2 40 0.2 OUTPUT VOLTAGEDEVIATION (mV) ––2240000 VOUT = 10V CADJ = 1m F CADJ = 0 OUTPUT VOLTAGEDEVIATION (V)––000...1012 CIN = 1m FC ATDAJN =T A1Lm UFM CADJ = 0 UIT CURRENT (A) 001...680 INPUT VOLTAGEDEVIATION (V) –11611320410 CCIOIONUU T=T = =1 0 m1.F20 AmTAF NTTAANLTUA1ML0U0M 200 LOAD CURRENT (A)–1001....053500 COUT = 10m F TANT5A0LUMVPVOIRNUE =TL O=1A 31VD0 V= 100mA100 SHORT-CIRC 00..024 0 5OUTPGUUT1A 0CRUARNRTEEEN1DT5 20 25 TIME (m s) TIME (m s) INPUT/OUTPUT DIFFERENTIAL (V) LT1086 • TPC13 LT1086 • TPC14 LT1086 • TPC15 LT1086H Ripple Rejection LT1086H Dropout Voltage LT1086H Load Regulation vs Current 2 0.10 100 L (V) INDICATES GUARANTEED TEST POINT D I = 0.5A 90 UM INPUT/OUTPUT DIFFERENTIA 1 –505°°CC ££ TTJJT T££JTJ J=11= 52= –105 525°°550CC°°°CCC UTPUT VOLTAGE DEVIATION (%)–––0000....010155050 RIPPLE REJECTION (dB) 46782350000000 VOUVVffTRR RR= ==II PP5 PP21VLL02EEk0 HH££ zz 03.V5PV-PP-P MINIM O 10 CCAODUJT == 2255mm FF 0 –0.20 0 0 0.1 0.2 0.3 0.4 0.5 –50 –25 0 25 50 75 100 125 150 0 0.1 0.2 0.3 0.4 0.5 OUTPUT CURRENT (A) TEMPERATURE (°C) OUTPUT CURRENT (A) LT1086 • TPC16 LT1086 • TPC17 LT1086 • TPC18 sn1086 1086ffs 6

LT1086 Series TYPICAL PERFORWMANUCE CHARACTERISTICS LT1086H Maximum Power LT1086H Ripple Rejection Dissipation* 100 5 90 VRIPPLE £ 3VP-P VRIPPLE £ 0.5VP-P 80 (VIN – VOUT) ‡ 3V 4 dB) 70 N ( (VIN – VOUT) ‡ VDROPOUT LE REJECTIO 456000 POWER (W) 32 LT1086MH PP 30 RI 20 CADJ = 200m F AT FREQUENCIES < 60Hz 1 CADJ = 25m F AT FREQUENCIES > 60Hz 10 IOUT = 0.5A 0 0 10 100 1k 10k 100k 50 60 70 80 90 100110120130140150 FREQUENCY (Hz) CASE TEMPERATURE (°C) LT1086 • TPC19 *AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE LT1086 • TPC20 BLOCK DIAGRAWM VIN + – THERMAL LIMIT 1086 • BD VADJ VOUT sn1086 1086ffs 7

LT1086 Series APPLICATIOUNS INUFORWMATIOUN The LT1086 family of 3-terminal regulators is easy to use response with heavy load current changes. Output capaci- and has all the protection features that are expected in high tance can be increased without limit and larger values of performance voltage regulators. They are short-circuit output capacitor further improve stability and transient protected and have safe area protection as well as thermal response of the LT1086 regulators. shutdown to turn off the regulator should the temperature Another possible stability problem that can occur in mono- exceed about 165(cid:176) C at the sense point. lithic IC regulators is current limit oscillations. These can These regulators are pin compatible with older 3-terminal occur because in current limit, the safe area protection adjustable devices, offer lower dropout voltage and more exhibits a negative impedance. The safe area protection precise reference tolerance. Further, the reference stabil- decreases the current limit as the input-to-output voltage ity with temperature is improved over older types of increases.That is the equivalent of having a negitive resis- regulators. The only circuit difference between using the tance since increasing voltage causes current to decrease. LT1086 family and older regulators is that they require an Negative resistance during current limit is not unique to output capacitor for stability. the LT1086 series and has been present on all power IC regulators. The value of negative resistance is a function of Stability how fast the current limit is folded back as input-to-output voltage increases. This negative resistance can react with The circuit design used in the LT1086 family requires the capacitors or inductors on the input to cause oscillation use of an output capacitor as part of the device frequency during current limiting. Depending on the value of series compensation. For all operating conditions, the addition of 150m F aluminum electrolytic or a 22m F solid tantalum on resistance, the overall circuitry may end up unstable. Since this is a system problem, it is not necessarily easy to solve; the output will ensure stability. Normally capacitors much however, it does not cause any problems with the IC smaller than this can be used with the LT1086. Many regulator and can usually be ignored. different types of capacitors with widely varying charac- teristics are available. These capacitors differ in capacitor Protection Diodes tolerance (sometimes ranging up to – 100%), equivalent series resistance, and capacitance temperature coeffi- In normal operation the LT1086 family does not need any cient. The 150m F or 22m F values given will ensure stability. protection diodes. Older adjustable regulators required protection diodes between the adjustment pin and the When using the LT1086 the adjustment terminal can be output and from the output to the input to prevent over- bypassed to improve ripple rejection. When the adjust- stressing the die. The internal current paths on the LT1086 ment terminal is bypassed the requirement for an output adjustment pin are limited by internal resistors. Therefore, capacitor increases. The values of 22m F tantalum or 150m F even with capacitors on the adjustment pin, no protection aluminum cover all cases of bypassing the adjustment diode is needed to ensure device safety under short-circuit terminal. For fixed voltage devices or adjustable devices conditions. without an adjust pin bypass capacitor, smaller output capacitors can be used with equally good results. The table Diodes between input and output are usually not needed. below shows approximately what size capacitors are needed The internal diode between the input and the output pins to ensure stability. of the LT1086 family can handle microsecond surge currents of 10A to 20A. Even with large output capaci- Recommended Capacitor Values tances, it is very difficult to get those values of surge INPUT OUTPUT ADJUSTMENT currents in normal operation. Only with high value output 10m F 10m F Tantalum, 50m F Aluminum None capacitors such as 1000m F to 5000m F, and with the input 10m F 22m F Tantalum, 150m F Aluminum 20m F pin instantaneously shorted to ground, can damage occur. A crowbar circuit at the input of the LT1086 can generate Normally, capacitor values on the order of 100m F are used those kinds of currents and a diode from output to input is in the output of many regulators to ensure good transient then recommended. Normal power supply cycling or even sn1086 1086ffs 8

LT1086 Series APPLICATIOUNS INUFORWMATIOUN plugging and unplugging in the system will not generate the power supply may need to be cycled down to zero and current large enough to do any damage. brought up again to make the output recover. The adjustment pin can be driven on a transient basis Ripple Rejection – 25V, with respect to the output without any device degradation. Of course as with any IC regulator, exceeding For the LT1086 the typical curves for ripple rejection the maximum input-to-output voltage differential causes reflect values for a bypassed adjust pin. This curve will be the internal transistors to break down and none of the true for all values of output voltage. For proper bypassing protection circuitry is functional. and ripple rejection approaching the values shown, the impedance of the adjust pin capacitor at the ripple fre- D1 quency should equal the value of R1, (normally 100W to 1N4002 (OPTIONAL) 120W ). The size of the required adjust pin capacitor is a function of the input ripple frequency. At 120Hz the adjust pin capacitor should be 13m F if R1 = 100W ; at 10kHz only VIN IN LT1086 OUT + VOUT 0.16m F is needed. ADJ R1 COUT 150µF + For circuits without an adjust pin bypass capacitor the C10AµDJF R2 ripple rejection will be a function of output voltage. The LT1086 • AI01 output ripple will increase directly as a ratio of the output Overload Recovery voltage to the reference voltage (V /V ). For ex- OUT REF ample, with the output voltage equal to 5V and no adjust Like any of the IC power regulators, the LT1086 has safe pin capacitor, the output ripple will be higher by the ratio area protection. The safe area protection decreases the of 5V/1.25V or four times larger. Ripple rejection will be current limit as input-to-output voltage increases and degraded by 12dB from the value shown on the LT1086 keeps the power transistor inside a safe operating region curve. Typical curves are provided for the 5V and 12V for all values of input-to-output voltage. The LT1086 devices since the adjust pin is not available. protection is designed to provide some output current at all values of input-to-output voltage up to the device Output Voltage breakdown. The LT1086 develops a 1.25V reference voltage between When power is first turned on, as the input voltage rises, the output and the adjust terminal (see Figure 1). By the output follows the input, allowing the regulator to start placing resistor R1 between these two terminals, a con- up into very heavy loads. During the start-up, as the input stant current is caused to flow through R1 and down voltage is rising, the input-to-output voltage differential through R2 to set the overall output voltage. Normally this remains small, allowing the regulator to supply large current is chosen to be the specified minimum load output currents. With high input voltage, a problem can current of 10mA. Because I is very small and constant ADJ occur wherein removal of an output short will not allow the when compared with the current through R1, it repre- output voltage to recover. Older regulators such as the sents a small error and can usually be ignored. For fixed 7800 series also exhibited this phenomenon, so it is not voltage devices R1 and R2 are included in the device. unique to the LT1086. The problem occurs with a heavy output load when the input voltage is high and the output voltage is low, such as VIN IN LT1086 OUT + VOUT immediately after a removal of a short. The load line for ADJ VREF R1 1T0AmNFTALUM such a load may intersect the output current curve at two 5I0AmDAJ ( ) points. If this happens there are two stable output operat- R2 R2 ing points for the regulator. With this double intersection VOUT = VREF 1 + R 1 + IADJ R2 1086 • F01 Figure 1. Basic Adjustable Regulator sn1086 1086ffs 9

LT1086 Series APPLICATIOUNS INUFORWMATIOUN Load Regulation Thermal Considerations Because the LT1086 is a 3-terminal device, it is not The LT1086 series of regulators have internal power and possible to provide true remote load sensing. Load regu- thermal limiting circuitry designed to protect the device lation will be limited by the resistance of the wire connect- under overload conditions. For continuous normal load ing the regulator to the load. The data sheet specification conditions however, maximum junction temperature rat- for load regulation is measured at the bottom of the ings must not be exceeded. It is important to give careful package. Negative side sensing is a true Kelvin connec- consideration to all sources of thermal resistance from tion, with the bottom of the output divider returned to the junction to ambient. This includes junction-to-case, case- negative side of the load. Although it may not be immedi- to-heat sink interface and heat sink resistance itself. New ately obvious, best load regulation is obtained when the thermal resistance specifications have been developed to top of the resistor divider R1 is connected directly to the more accurately reflect device temperature and ensure case not to the load, as illustrated in Figure 2. If R1 were safe operating temperatures. The data section for these connected to the load, the effective resistance between the new regulators provides a separate thermal resistance and regulator and the load would be: maximum junction temperature for both the Control Sec- tion and the Power Transistor. Previous regulators, with a ( ) single junction-to-case thermal resistance specification, R2 + R1 RP , RP = Parasitic Line Resistance used an average of the two values provided here and R1 therefore could allow excessive junction temperatures under certain conditions of ambient temperature and heat RP sink resistance. To avoid this possibility, calculations PARASITIC LINE RESISTANCE should be made for both sections to ensure that both VIN IN LT1086 OUT thermal limits are met. ADJ R1* For example, using a LT1086CK (TO-3, Commercial) and RL assuming: R2* V (max continuous) = 9V, V = 5V, I = 1A, IN OUT OUT T = 75(cid:176) C, q = 3(cid:176) C/W, *CONNECT R1 TO CASE A HEAT SINK CONNECT R2 TO LOAD 1086 • F02 q CASE-TO-HEAT SINK = 0.2(cid:176) C/W for T package with thermal compound. Figure 2. Connections for Best Load Regulation Power dissipation under these conditions is equal to: Connected as shown, R is not multiplied by the divider P P = (V – V )(I ) = 4W ratio. R is about 0.004W per foot using 16-gauge wire. D IN OUT OUT P This translates to 4mV/ft at 1A load current, so it is Junction temperature will be equal to: important to keep the positive lead between regulator and T = T + P (q + q + q ) J A D HEAT SINK CASE-TO-HEAT SINK JC load as short as possible and use large wire or PC board For the Control Section: traces. T = 75(cid:176) C + 4W(3(cid:176) C/W + 0.2(cid:176) C/W + 1.5(cid:176) C/W) = 94.6(cid:176) C J Note that the resistance of the package leads for the H 95(cid:176) C < 125(cid:176) C = T (Control Section JMAX package » 0.06W /inch. While it is usually not possible to Commercial Range) connect the load directly to the package, it is possible to For the Power Transistor: connect larger wire or PC traces close to the case to avoid voltage drops that will degrade load regulation. TJ = 75(cid:176) C + 4W(3(cid:176) C/W + 0.2(cid:176) C/W + 4(cid:176) C/W) = 103.8(cid:176) C 103.8(cid:176) C < 150(cid:176) C = T (Power Transistor JMAX For fixed voltage devices the top of R1 is internally Kelvin Commercial Range) connected and the ground pin can be used for negative side sensing. sn1086 1086ffs 10

LT1086 Series APPLICATIOUNS INUFORWMATIOUN In both cases the junction temperature is below the In all cases proper mounting is required to ensure the best maximum rating for the respective sections, ensuring possible heat flow from the die to the heat sink. Thermal reliable operation. compound at the case-to-heat sink interface is strongly recommended. In the case of the H package, mounting the Junction-to-case thermal resistance for the K and T pack- ages is specified from the IC junction to the bottom of the device so that heat can flow out the bottom of the case will case directly below the die. This is the lowest resistance significantly lower thermal resistance (» a factor of 2). If the case of the device must be electrically isolated, a path for heat flow. While this is also the lowest resistance path for the H package, most available heat sinks for this thermally conductive spacer can be used as long as its package are of the clip-on type that attach to the cap of the added contribution to thermal resistance is considered. Note that the case of all devices in this series is electrically package. The data sheet specification for thermal resis- tance for the H package is therefore written to reflect this. connected to the output. TYPICAL APPLICATIONUS 5V, 1.5A Regulator VIN ‡ 6.5V IN LT1086 OUT 5V AT 1.5A ADJ 121W + 1% + 10µF 10µF* TANTALUM 365W 1% LT1086 • AI02 *REQUIRED FOR STABILITY SCSI-2 Active Termination TERMPWR 110W 1N5817 2% 110W IN LT1086-2.85OUT GND + + 4.25V 10m F 10m F 0.1m F TO 5.25V TANTALUM TANTALUM CERAMIC 121%0W 110W 18 TOTAL 110W 2% 110W LT1086 • TA03 sn1086 1086ffs 11

LT1086 Series TYPICAL APPLICATIONUS 1.2V to 15V Adjustable Regulator 5V Regulator with Shutdown VIN IN LT1086 OUT VOUT† VIN IN LT1086 OUT 5V ADJ R1 ADJ 121W + 121W + 1% + C1* C2 10µF + 10µF R5k2 100µF TTL 1k 2N3904 365W 100µF 1% 1k *NEEDED IF DEVICE IS FAR FROM FILTER CAPACITORS LT1086 • TA05 ( ) †VOUT = 1.25V 1 +RR21 LT1086 • TA04 Battery Charger Adjusting Output Voltage of Fixed Regulators IF LT1086 RS OUT VIN IN VOUT VIN > 12V + IN LT1086-5 OUT + 5V TO 10V 1.25V ADJ 10µF GND 100µF ( R2) R1 + VOUT – 1.25 1 +R1 10µF* 1k IF = ( ) R2 LT1086 • TA06 LT1086 • TA07 R2 – RS 1 + R1 *OPTIONAL IMPROVES RIPPLE REJECTION ( ) dIF = 1 dVOUT ( R2) – RS 1 + R1 Regulator with Reference Protected High Current Lamp Driver VIN > 11.5V + IN LT1086-5 OUT + 10V OUT LT1086 IN 15V TTL OR 10µF GND 100µF CMOS ADJ 12V 1A 5V LT1029 10k LT1086 • TA08 LT1086 • TA10 Remote Sensing RP (MAX DROP 300mV) VIN IN LT1086 OUT V5VOUT + ADJ 100m F VIN 7 2 – 25W 6 LM301A + 1 + 3 1k 10m F 121W 8 RL 5m F 4 365W 100pF + 25W RETURN RETURN LT1086 • TA09 sn1086 1086ffs 12

LT1086 Series TYPICAL APPLICATIONUS High Efficiency Dual Linear Supply L1 285m H 12V IN LT1086 OUT HEAT SINK MBR360 1000m F ADJ 124W * 1.5A 2N6667 Q1 DARLINGTON 10k 1k + 510k 2.4k LT1004-2.5 30k + + + 100m F 8 20k* 30.1k* MDA201 4700m F + 2 1.07k* D1 1N4002 7 – LT1011 3 – 4 L1 130VAC STANCOR 285m H TO 90VAC P-8685 IN LT1086 OUT HEAT SINK MBR360 1000m F ADJ 124W * 2N6667 Q2 DARLINGTON 10k 1k + 510k 2.4k LT1004-2.5 30k + + + 100m F 8 20k* 30.1k* MDA201 4700m F + 2 1.07k* D2 1N4002 7 – LT1011 3 – 4 –12V *1% FILM RESISTORS 1.5A MDA = MOTOROLA LT1086 • TA11 L1 = PULSE ENGINEERING, INC. #PE-92106 High Efficiency Dual Supply FEEDBACK PATH MUR410 5V OUTPUT (TYPICAL) + 470µF MUR410 12V IN LT1086 OUT 1.5A ADJ 124W * + + 470µF + 10µF 1N4002 VIN 10µF 1.07k* MUR410 IN LT1086 OUT SWITCHING ADJ 124W * REGULATOR + + 470µF + 10µF 1N4002 10µF 1.07k* –12V *1% FILM RESISTORS 1.5A LT1086 • TA12 sn1086 1086ffs 13

LT1086 Series TYPICAL APPLICATIONUS Battery Backed Up Regulated Supply Improving Ripple Rejection VIN + IN LT1086-5 OUT 55.V2 VB ALTINTEERY VIN ‡ 6.5V IN LT1086 OUT R1 VOUT = 5V 10µF GND + ADJ 121W 1% 50W 10µF 150µF R2 + SELECT FOR 365W C1 CHARGE RATE 1% 10µF* IN LT1086-5 OUT LT1086 • TA14 + + *C1 IMPROVES RIPPLE REJECTION. 6.5V 10µF GND 100µF XC SHOULD BE » R1 AT RIPPLE FREQUENCY LT1086 • TA13 Automatic Light Control Low Dropout Negative Supply VIN IN LT1086 OUT + ADJ 1.2k VIN IN LT1086-12 OUT 10µF 100µF + GND + 10,000µF 100µF VOUT = –12V LT1086 • TA15 FLOATING INPUT LT1086 • TA16 PACKAGE DESCRIPTIOUN H Package 3-Lead TO-39 Metal Can (Reference LTC DWG # 05-08-1330) 0.350 – 0.370 (8.890 – 9.398) 0.200 0.305 – 0.335 (5.080) (7.747 – 8.509) TYP 0.100 0.050 (2.540) (1.270) MAX 0.165 – 0.185 (4.191 – 4.699) PIN 1 REFERENCE 0.029 – 0.045 PLANE * (0.737 – 1.143) 0.100 (2.540) 0.028 – 0.034 (0.711 – 0.864) 0.016 – 0.021** 0.500 (0.406 – 0.533) (12.700) DIA MIN 45° H3(TO-39) 1098 *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND 0.045" BELOW THE REFERENCE PLANE 0.016 – 0.024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) OBSOLETE PACKAGE sn1086 1086ffs 14

LT1086 Series PACKAGE DESCRIPTIOUN K Package 2-Lead TO-3 Metal Can (Reference LTC DWG # 05-08-1310) 0.760 – 0.775 0.320 – 0.350 (19.30 – 19.69) (8.13 – 8.89) 0.060 – 0.135 (1.524 – 3.429) 0.420 – 0.480 (10.67 – 12.19) 0.038 – 0.043 (0.965 – 1.09) 1.177 – 1.197 (29.90 – 30.40) 0.655 – 0.675 (16.64 – 17.15) 0.210 – 0.220 (5.33 – 5.59) 0.151 – 0.161 (3.86 – 4.09) DIA, 2PLCS 0.167 – 0.177 (4.24 – 4.49) 0.425 – 0.435 R (10.80 – 11.05) 0.067 – 0.077 0.490 – 0.510 (1.70 – 1.96) (12.45 – 12.95) R K2 (TO-3) 1098 OBSOLETE PACKAGE M Package 3-Lead Plastic DD Pak (Reference LTC DWG # 05-08-1460) 0.060 (1.524) 0.390 – 0.415 0.256 0.060 TYP (9.906 – 10.541) 0.165 – 0.180 (6.502) (1.524) (4.191 – 4.572) 0.045 – 0.055 15° TYP (1.143 – 1.397) +0.008 0.004 0.060 0.183 0.330 – 0.370 0.059 ( –0.004) (1.524) (4.648) (1.499) +0.203 (8.382 – 9.398) 0.102 TYP –0.102 0.095 – 0.115 (2.413 – 2.921) 0.075 (1.905) 0.090 – 0.110 0.050 – 0.012 (07..360200) (0.143+–00..001220) 0.050 (2.286 – 2.794) (00..031330 –– 00..052834) (1.270 – 0.305) +0.305 BOTTOM VIEW OF DD PAK 3.632 (1.270) –0.508 HATCHED AREA IS SOLDER PLATED BSC M (DD3) 1098 COPPER HEAT SINK sn1086 1086ffs Information furnished by Linear Technology Corporation is believed to be accurate and reliable. 15 However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

LT1086 Series PACKAGE DESCRIPTIOUN T Package 3-Lead Plastic TO-220 (Reference LTC DWG # 05-08-1420) 0.147 – 0.155 0.165 – 0.180 0.390 – 0.415 (3.734 – 3.937) (4.191 – 4.572) (9.906 – 10.541) DIA 0.045 – 0.055 (1.143 – 1.397) 0.230 – 0.270 (5.842 – 6.858) 0.570 – 0.620 0.460 – 0.500 (14.478 – 15.748) (11.684 – 12.700) 0.330 – 0.370 (8.382 – 9.398) 0.980 – 1.070 (24.892 – 27.178) 0.520 – 0.570 (13.208 – 14.478) 0.218 – 0.252 (5.537 – 6.401) 0.013 – 0.023 0.100 (0.330 – 0.584) 0.095 – 0.115 (2.540) 0.050 BSC 0.028 – 0.038 (1.270) (2.413 – 2.921) (0.711 – 0.965) TYP T3 (TO-220) 1098 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1129 700mA, Micropower, LDO V = 4.2V to 30V, V = 3.75V, I = 50m A, I = 16m A, IN OUT(MIN) Q SD DD, SOT-223, S8, TO-220, TSSOP-20 Packages LT1528 3A LDO for Microprocessor Applications V = 4V to 15V, V = 3.30V, I = 400m A, I = 125m A, IN OUT(MIN) Q SD Fast Transient Response, DD, TO-220 Packages LT1585 4.6A LDO , with Fast Transient Response V = 2.5V to 7V, V = 1.25V, I = 8mA, IN OUT(MIN) Q Fast Transient Response, DD, TO-220 Packages LT1761 100mA, Low Noise Micropower, LDO V = 1.8V to 20V, V = 1.22V, I = 20m A, I = <1m A, IN OUT(MIN) Q SD Low Noise < 20m V , Stable with 1m F Ceramic Capacitors, ThinSOTTM Package RMS P-P LT1762 150mA, Low Noise Micropower, LDO V = 1.8V to 20V, V = 1.22V, I = 25m A, I = <1m A, IN OUT(MIN) Q SD Low Noise < 20m V , MSOP Package RMS P-P LT1763 500mA, Low Noise Micropower, LDO V = 1.8V to 20V, V = 1.22V, I = 30m A, I = <1m A, IN OUT(MIN) Q SD Low Noise < 20m V , S8 Package RMS P-P LT1764/LT1764A 3A, Low Noise, Fast Transient Response, LDOs V = 2.7V to 20V, V = 1.21V, I = 1mA, I = <1m A, Low Noise IN OUT(MIN) Q SD < 40m V , “A” Version Stable with Ceramic Capacitor, DD, TO-220 Packages RMS P-P LT1962 300mA, Low Noise Micropower, LDO V = 1.8V to 20V, V = 1.22V, I = 30m A, I = <1m A, IN OUT(MIN) Q SD Low Noise < 20m V , MS8 Package RMS P-P LT1963/LT1963A 1.5A, Low Noise, Fast Transient Response, LDOs V = 2.1V to 20V, V = 1.21V, I = 1mA, I = <1m A, IN OUT(MIN) Q SD Low Noise < 40m V ,“A” Version Stable with Ceramic Capacitor, RMS P-P DD, TO-220, SOT-223, S8 Packages LT1964 200mA, Low Noise Micropower, Negative LDO V = –0.9V to –20V, V = –1.21V, I = 30m A, I = 3m A, IN OUT(MIN) Q SD Low Noise < 30m V , Stable with Ceramic Capacitors, ThinSOT Package RMS P-P ThinSOT is a trademark of Linear Technology Corporation. sn1086 1086ffs 16 Linear Technology Corporation LT/TP 0703 1K REV F • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 l FAX: (408) 434-0507 l www.linear.com © LINEAR TECHNOLOGY CORPORATION 1988