LR8 High-Input Voltage, Adjustable, 3-Terminal, Linear …

1 2015-2017 Microchip Technology 1LR8 Features Input voltage Range Adjustable Output Regulation 5% Output voltage Tolerance Output Current Limiting 10 A Typical ADJ Current Internal Junction Temperature LimitingApplications Offline SMPS startup circuits Adjustable high- voltage constant current source Industrial controls Motor controls Battery chargers Power suppliesGeneral DescriptionLR8 is a high- voltage , low-output current, adjustablelinear regulator. This regulator has a wide operatinginput voltage range of The output voltagecan be adjusted from , provided that the inputvoltage is at least 12V greater than the output output voltage can be adjusted by means of twoexternal resistors, R1 and R2, as shown in the typicalapplication circuits. LR8 regulates the voltage differ-ence between VOUT and ADJ pins to a nominal value The is amplified by the external resistorratio R1 and R2.

2 An internal constant bias current, oftypically 10 A, is connected to the ADJ pin. Thisincreases VOUT by a constant voltage of 10 A provides both current and temperature output current limit is typically 20 mA and theminimum temperature limit is +125 C. An output short-circuit current will therefore be limited to 20 mA. Whenthe junction temperature reaches its temperature limit,the output current and/or output voltage will decreaseto prevent the junction temperature from exceeding itstemperature limit. For SMPS start-up circuit applica-tions, LR8 turns off when an external voltage greaterthan the output voltage of the LR8 is applied to VOUT ofthe LR8. To maintain stability, a bypass capacitor F or larger and a minimum DC output current of500 A are is available in TO-243AA (SOT-89), TO-252 (D-PAK) and TO-92 voltage , Adjustable, 3-Terminal, Linear RegulatorLR8DS20005399B-page 2 2015-2017 Microchip Technology TypeFunctional Block Diagram TO-92 See Table 2-1 for pin informationTO-252TO-243AA (SOT-89)VINADJVOUTVOUTADJ9,19287 VINADJVOUTO vertemp &Overcurrent10 A VINVOUTADJLR8 PassElement 2015-2017 Microchip Technology ELECTRICAL CHARACTERISTICSABSOLUTE MAXIMUM RATINGS VIN Input voltage (voltages ref to ADJ).

3 To +480 VOutput voltage to +470 VOperating ambient temperature range .. 40 C to +85 COperating junction temperature range .. 40 C to +125 CStorage temperature .. 65 C to +150 C Notice: Stresses above those listed under Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device 4 2015-2017 Microchip Technology CHARACTERISTICS11 Test Conditions unless otherwise specified: -40 C <TA < 85 ConditionsInput to output voltage differenceVIN- VOUT12450 VOverall output voltage < VIN< 400V, R1= , R2=0375400425VR1= , R2= 782 k Line regulation < VIN< 400V, VOUT=5V,IOUT= , VOUT=5V, mA < IOUT<10mATemperature regulation-1+1%VIN=17V, VOUT=5V, IOUT=10mA, -40 C<TA<85 COutput current limitIOUT1030mATJ< 85 C, VIN-VOUT= > 125 C, VIN-VOUT=450 VMinimum output R1 and load currentAdjust output AMinimum output load FRipple rejection ratio VOUT/ VIN5060dB120 Hz, VOUT=5 VJunction temperature limitTLIMIT125 CTABLE 1-1:TYPICAL THERMAL RESISTANCEP ackage jaTO-252 (D-PAK)81 C/WTO-92132 C/WTO-243AA (SOT-89)133 C/WTABLE 1-2.

4 THERMAL CHARACTERISTICSP ackagePower Dissipation@TA = C jc C/W ja (SOT-89) on FR4 board, 25 mm x 2 mm x mmTO-252 (D-PAK) 2015-2017 Microchip Technology PIN DESCRIPTIONThe locations of the pins are listed in Package APPLICATION CIRCUITSFIGURE 3-1:Typical Application Circuit. FIGURE 3-2: High-Input voltage , Output Linear 2-1:PIN DESCRIPTIONF unctionDescriptionVINR egulator input. voltage ** Required for conditions where VIN is less than R2C2 C1 RLOADVOUT VOUTADJVINVIN = 17 to 450V * k 1% FC1 RLOAD k VOUT = k 1%* Required for conditions where VIN is less than VOUT VOUT = 1+R2 +,$'- [ 5 R1LR8 VOUTADJVINLR8DS20005399B-page 6 2015-2017 Microchip Technology 3-3: SMPS Start-Up Circuit. FIGURE 3-4: High- voltage , Adjustable, Constant-Current Source.+ VOUT1 - VCCVAUXILIARYVIN = (VOUT + 12V) to 450 VFBPWM IC + VOUT1 - LR8 VOUTADJVINLR8 VIN =(VOUT + 12V) to 450VR Load IOUT = R+ FVOUTADJVIN 2015-2017 Microchip Technology 7LR8 FIGURE 3-5: Typical Performance Curves 1 of ADJ VIN F VOUT = 12V, FVOUT = (V)T (junction) (OC)Temperature Variation-50 -25 0 25 50 75 100 125 Adjustment CurrentIADJ ( A)T (junction) (OC)-50 -25 0 25 50 75 100 1256789101112 VIN = 200 VVOUT (V)IOUT (mA)Load Regulation0 2 4 6 8 1% 1% FRLOADVOUT = LR8LR8 VIN = 400 VVIN = 12 VLR8DS20005399B-page 8 2015-2017 Microchip Technology Inc.]

5 FIGURE 3-6: Typical Performance Curves 2 of 1% 1% F1k VOUT = to 50 VVOUT vs. VINVOUT (V)VIN (V)0 10203040500123456 Ripple RejectionRipple Regection Ratio (dB)IOUT (mA)0 2 4 6 8 1% 1% FRLOADVOUT = @ 60Hz3025201510-40 -20 0 20 40 60 80 100 Temperature (OC)lCL (mA)LR8LR8 2015-2017 Microchip Technology 9LR8 FIGURE 3-7: Typical Performance Curves 3 of Transient ResponseLine Transient ResponseLine Power Up TransientLoad Transient Response Line Transient ResponseADJ 1% 1% F 10k VOUT = LR8 532 sw 1% 1% F10k VOUT = Closed SW Open Power Down TransientLR8DS20005399B-page 10 2015-2017 Microchip Technology Marking Code or Customer-specific informationYYear code (last digit of calendar year)YYYear code (last 2 digits of calendar year)WWWeek code (week of January 1 is week 01 )NNNA lphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn)*This package is Pb-free.

6 The Pb-free JEDEC designator ( )can be found on the outer packaging for this :In the event the full Microchip part number cannot be marked on one line, it willbe carried over to the next line, thus limiting the number of availablecharacters for product code or customer-specific information. Package may ornot include the corporate TO-252 (D-PAK)ExampleYYWWNNNXXXXXXXXXe315163438 K4 LRe33-lead TO-92 YWWNNNXXXXXXXXXXe3 Example516343LR8N3e33-lead TO-243AA * (SOT-89)ExampleXXXYYWWNNNLR8516343 2015-2017 Microchip Technology 11LR8 Note: For the most current package drawings, see the Microchip Packaging Specification at 12 2015-2017 Microchip Technology TO-243AA (SOT-89) Package Outline (N8)SymbolAbb1 CDD1EE1ee1 HLDimensions(mm) Registration TO-243, Variation AA, Issue C, July 1986. This dimension differs from the JEDEC drawingDrawings not to 3ee1 Top ViewSide ViewLNote: For the most current package drawings, see the Microchip Packaging Specification at : For the most current package drawings, see the Microchip Packaging Specification at 2015-2017 Microchip Technology 13LR8 Note: For the most current package drawings, see the Microchip Packaging Specification at 14 2015-2017 Microchip Technology : 2015-2017 Microchip Technology 15LR8 APPENDIX A: REVISION HISTORYR evision B (November 2017)The following is the list of Figure typographical A (June 2015) Original Release of this 16 2015-2017 Microchip Technology IDENTIFICATION SYSTEMTo order or obtain information, , on pricing or delivery, refer to the factory or the listed sales office.

7 Device:LR8= High-Input voltage , Adjustable, 3-Terminal, Linear RegulatorPackage:N3= TO-92 K4= TO-252 (D-PAK)N8= TO-243AA (SOT-89) EnvironmentalG= Lead (Pb)-free/ROHS-compliant packageMedia Type:(blank) = 1000/Bag for N3 packages= 2000/Reel for K4 packages= 2000/Reel for N8 packagesP003= 2000/Reel for N3 packageExamples:a)LR8N3-GTO-92 package, 1000/bagb)LR8N3-G-P003:TO-92 package, 2000 )LR8K4-GTO-252 package, 2000/reeld)LR8N8-GTO-243AA package, 2000/reelPART 2015-2017 Microchip Technology 17 Information contained in this publication regarding deviceapplications and the like is provided only for your convenienceand may be superseded by updates. It is your responsibility toensure that your application meets with your MAKES NO REPRESENTATIONS ORWARRANTIES OF ANY KIND WHETHER EXPRESS ORIMPLIED, WRITTEN OR ORAL, STATUTORY OROTHERWISE, RELATED TO THE INFORMATION,INCLUDING BUT NOT LIMITED TO ITS CONDITION,QUALITY, PERFORMANCE, MERCHANTABILITY ORFITNESS FOR PURPOSE.

8 Microchip disclaims all liabilityarising from this information and its use. Use of Microchipdevices in life support and/or safety applications is entirely atthe buyer s risk, and the buyer agrees to defend, indemnify andhold harmless Microchip from any and all damages, claims,suits, or expenses resulting from such use. No licenses areconveyed, implicitly or otherwise, under any Microchipintellectual property rights unless otherwise Microchip name and logo, the Microchip logo, AnyRate, AVR, AVR logo, AVR Freaks, BeaconThings, BitCloud, CryptoMemory, CryptoRF, dsPIC, FlashFlex, flexPWR, Heldo, JukeBlox, KEELOQ, KEELOQ logo, Kleer, LANC heck, LINK MD, maXStylus, maXTouch, MediaLB, megaAVR, MOST, MOST logo, MPLAB, OptoLyzer, PIC, picoPower, PICSTART, PIC32 logo, Prochip Designer, QTouch, RightTouch, SAM-BA, SpyNIC, SST, SST Logo, SuperFlash, tinyAVR, UNI/O, and XMEGA are registered trademarks of Microchip Technology Incorporated in the and other , The Embedded Control Solutions Company, EtherSynch, Hyper Speed Control, HyperLight Load, IntelliMOS, mTouch, Precision Edge, and Quiet-Wire are registered trademarks of Microchip Technology Incorporated in the Key Suppression, AKS, Analog-for-the-Digital Age, Any Capacitor, AnyIn, AnyOut, BodyCom, chipKIT.

9 ChipKIT logo, CodeGuard, CryptoAuthentication, CryptoCompanion, CryptoController, dsPICDEM, , Dynamic Average Matching, DAM, ECAN, EtherGREEN, In-Circuit Serial Programming, ICSP, Inter-Chip Connectivity, JitterBlocker, KleerNet, KleerNet logo, Mindi, MiWi, motorBench, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code Generation, PICDEM, , PICkit, PICtail, PureSilicon, QMatrix, RightTouch logo, REAL ICE, Ripple Blocker, SAM-ICE, Serial Quad I/O, , SQI, SuperSwitcher, SuperSwitcher II, Total Endurance, TSHARC, USBC heck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are trademarks of Microchip Technology Incorporated in the and other is a service mark of Microchip Technology Incorporated in the Storage Technology is a registered trademark of Microchip Technology Inc. in other is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip Technology Inc., in other countries.

10 All other trademarks mentioned herein are property of their respective companies. 2015-2017, Microchip Technology Incorporated, All Rights Reserved. ISBN: 978-1-5224-2321-8 Note the following details of the code protection feature on Microchip devices: Microchip products meet the specification contained in their particular Microchip Data Sheet. Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. Microchip is willing to work with the customer who is concerned about the integrity of their code. Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code.