Demo Manual
Transcription
Demo Manual
__ sffiw DEMCMANUALDC367 LOWDROPOUT REGULATOR LTt963 L5A LowNoiseLDORegulotor DCSCRIPTION Demonstration circuitDC3O7 isa lownoisemicropowerRFpower supplies and,inlarger systems, aslocalregulavoltage regulator usingtheLT@1963 in theg-leadS0 tors.Theability totolerate awidevariety ofoutput capacipackage. Circuits designed withtheLT1963 areused torsmakes the1T1963 idealinspaceand cost-sensitive primarily phones, incellular voltage controlled oscillators, systems. ,g,LTC ardLTareregistered trademarks of Line.r' t.rnnotogyToiiiEiiii. PCRFORMRNCC SUMMRRY TA= 25oC, Vlx= 2.5V,VSffiT = 5V,l1s4p = 1mA,Vgul= 1.21V (JPZ setonPins1-2),unless othenrvise specified. PARAMETER CONDITIONS Inputvoltage Hange MIN 2.5 UutputV0ltage uurpuvotrage (N0te 1 t,tJl = 2.5V,JP2onPins3-4 Vrru Vlru= 2.8V,JP2onPins5-6 = 3.5V,JP2onPins7-8 Vrru = 4.3V,JP2onPins9-10 Vrru AVlx= l.$V{s!6Y uurput vottage (Note 1) (Note 0utputVoltage 1) uurpur vorrage (Note 1 Line Begulation 0uiescent Current 0utputVoltage Noise UNITS vV 20 1.210 1.228 I Als61s= 1mAto 1.5A 0n-to-Otf 0tf-to-0n,lroRo= 1mA lLolo= 1.5A,BW= 1OHz to 100kHz MAX L46S 1.500 I . C J J '1.759 1,803 t . u c b 2.417 2.491 2.585 3 . 1 7 1 3.280 3.420 210 Alss4g= Q6[ L0a0 Heguhtt0n SHDN PinThreshold TYP 0.45 I \/ t mV mA t.c 0.2 0.65 1 0.85 40 t.o Nole1:0utput voltage variations include 11%tolerance offeedback divider network. Fortighter voltage range, uselower tolerance resistors o;; voltage 0utput devices. ol V PVnn,ts t* TYPICRT PCRFORMRNCC CHRRRCT€RISTICS RNDBORRDPHOTO Typical Dropout Voltage 1T1963 (3.3VOutput) 1(lHzto 100kHz 0utputNoise 500 450 400 e I T,r= 12i vvv u O photo) Gomponent Side(Board I "-z ZJU 5 zoo 3 rso I E o 1oo 50 f// 0 0 uouT= l uFr l l s a e= 1 . 5 A 0.2 0.4 0.6 0.8 1.0 1.2 1 . 4 1 . 6 0UTPUT (A) CURRENT 0s7. Gol lTl,u]s* -1 l DEMOMANUALDC367 LOWDROPOUT REGULATOR PRCI{RG€ RNDSCH€MRTIC DIRGRRM5 LT1 963ES8 TOPVIEW OUT ADJ GND NC 58PACKAGE 8.LEAD PLASTIC SO EJ OUT IN LTl 963 OUT GND ADJ GND GND SFDN BYP T 10pF 1n\/ 3 2 1 6I = E4 GND Figure 1.1T1963 f Sn fo, Noise Micropower LDO Regulator PRNTS IIST BEFERENCE DESIGNATOR OUANTTTY PART NUMBER ADJl n 0402 06032c 105ZAT1 A c2 1 El to E4 t JP1 1 JP2 Shunts forJpl Shunts forJp2 R1 nl R3 R4 R5 U1 2 tAJAt06M010R 2308-2 2802S-02-G.1 6351-12P1 cctJ2MM-138G CTAIJlMM.G cR05-9760FM cR05-2001 FM cR05-4321 FM cR0s-698.1FM cR0s-41 21FM LT.I963ES8 DESCRIPTION upu0nal lpf 10VYsV80%Caoacitor 1fuF10VTantalum Capacrtor t-fln u.U64" HoleTerminal Turret 2-Pin I RowO.Ozg cclumoeiuonnector, SMT2X6, 0.39" Gap snunt 0.079" Center ununts 0.39cc 976lnOW 1%Chipnesistoi-2k1/16W 1%Chip nesistoi4.32k 1/16W 1%Chip R;Jsro, 6.98k 1/16W 1%Chip Re;sto, 4.12k 1116W t,t"Cfrip nesistol- ffi VENDOR AVX AVX Milt-Max Comm-Con Comm-Con Comm-Con Comm-Con MC MC MC AAC AAC LTC TETEPHONE (843)e46-0362 (843)946-0362 (516) e22-6000 (626) 301.4200 (626)301-4200 (626)301-4200 (626) 30'1-4200 (800)s08-152.1 (800) 508-1521 (800) 508-1521 (800)508-.1521 (714) 255-e186 (408) 432-1900 DEMCMANUALDC367 LOWDROPOUT REGULATOR OP€RRilON HO()K.UP Solidturretterminals areprovided foreasyconnection to stability, mostnotably withsmallcapacitors. A 1OpF supplies andtestequipment. Connect a0Vto 20V,1.64 minimum output value withESR of3e orlessisrecompowersupply across thelNandGNDterminals andthe mended to prevent oscillation. Transient response isa loadacross the0UTand GND terminals. pincan function TheS-FDN of outputcapacitance. Larger values of output bedisconnected fromlNviaJPlto allow forseparatecapacitance peak decrease provid deviations, ingimproved shutdown viaasecondary control control line.Jp2canbe transient resp0nse forlargeloadcurrent changes. Bypass usedto select anyofa number ofcommon fixedoutput capacitors, used todecouple powindividual components voltages, orused inconjunction withADJlto create a eredbytheregulator, increase theeffective output capacicustom voltage output using theformula: torvalue. - 1.21V)l29TvA ADJ]= (Vour Ceramic Gapacitors Thermal Characleristics Ceramic capacitors require extraconsideration. They are manufactured with variety a of dielectrics, eachwith Demonstration CircuitDC367 hasbeenlaidoutto illusdifferent behavior across temperature and applied power trateandachieve maximum handling capabilities. ybv, voltage. The most common dielectrics areZ5U, XbR Although two-layer asimple suffibo4d$ighthave been and X7R. The ZSU and prbvide YSV dietectrics high cientforelectrical operation oftheLT1g63, thefour-layer package, capacitance in a small butexhibit strong voltage ground planes board withviasto internal offersexcellent and temperature coefficients, as shown in Figures B'1and thermalcharacteristics. Atwo-layer board ofthesame size ySV 82. Used witha 5Vregulator, a 1OpF capacitor withnothermal viaswillexhibit athermal resistance of shows values as low as 1pF to 2prF overtheoperating 60'C/1/V, whereas 0C367 exhibits athermal resistance of temperature range. TheX5RandX7Rdielectrics have 50"CA/V, morestable characteristics andarem0resuitable for outputcapacitor use.TheX7Rtypehasbetterstability OUTPUT CAPACIT()R SELECTI()N over temperature, while theX5Ris lessexpensive and Theoutputcapacitor C3is a 1OprF tantalum capacitor. available inhigher values. Should adifferent outputcapacitor bedesired, caremust andtemperature coefficients arenottheonly beexercised withtheselection. Manyceramic capacitor Voltage problem sources. Some ceramic capacitors have d i e l e c t r i cesx h i b i ts t r o n gt e m p e r a t u a apiezor en d resp0nse. Apiezoelectric generates device voltage characteristics voltage thatreduce theireffective capaci- electric across its terminals due to mechanical tanceto aslowas10%to 20%of nominal stress, similar to overthefull piezoelectric the way a accelerometer temperature range. microphone Forfurtherinformation, or seeLinear Foraceramic capacitor, thestress Technology Application canbeinduced Note83,"Performance Verifica- works. vibrations by in the system or thermal tionofLowNoise, transients. LowDropout The Regulators," Appendix B, resulting voltages "Capacitor can cause appreciable Selection amounts ofnoise, Considerations," rep rinted below. especially when a ceramic capacitor is used fornojse CAPACIT()R SELECTI()N bypassing. A ceramic C()NSIDERATI()NS produced capacitor Figure B3's tracein resp0nse to lighttapping froma pencil. Similar Output Gapacitance andTransienl Response vibration-induced behavior canmasquerade asincreased output voltage noise. Theregulators aredesigned to bestable witha wide range ofoutput capacitors. 0utputcapacitor ESR affects -,(TfJIlmR 3 DEMOMANUALDC367 LOWDROPOUT REGULATOR OPCRRilON V()LTAGE OUTPUT N(}ISE Measuring voltage output noisecanbeatrickyprocess, enormous amount oftimeto provide accurate, relevant further complicated bythelowlevels ofnoise inherent in datatocustomers regarding noiseperformance. Forfura circuit suchasthis.Consideration mustbegiven to therinformation onmeasuring output voltage noise, see regulator operating conditions, aswellasthenoise band- LinearTechnology Application Note83,"Performance widthof interest. Linear Technology hasinvested an Verification ofLowNoise, LowDropout Regulators." BOTH CAPACITORS ARE16V, 1210CASE SIZE, 10r.tF n s u x5t -av \ = -{u ; z < -An =-- Y5V -6U -luu - 0 2 4 6 8 101214 (V) DCBIASVOLTAGE 0w 8r Figure B1.Ceramic Capacitor DCBiasChpracteristics Indicate Pronounced Voltage Dependencd. Device Must Ptovide Desired Capacitance Valueat0perating Voltage ,X5B ;sU ; \ d. -20 z ; -40 \ z E -60 rttl \ - BOTH CAPACITORS ARE16V, 1210 CASE SIZE,,lOrF , -100 -qn -tq 0 25 50 75 TEMPEMTURE ("C) 100 125 0667 4 Figure 82.Ceramic Capacitor Temperture Characteristics Show Large Capacitance Shift.Eftect Should Be Considered When Determining Circuit EnorBudget Figure 83.A Ceramic Capacitor Responds to Lightpencil g0pVp-p Tapping. Piezoelectric Based Response Approaches DEMOMANUALDC367 LOWDROPOUT REGULATOR OP€RRilON Noise Testing Consideralions Whatnoise isofinterest bandwidth andwhyisit interest- a60dBgainstage witha5Hzhighpass input.A3provides ing?Inmostsystems, therange of1OHz to100kHz isthe a 10H2, 2ndorderButtenruorth highpass characteristic. information signalprocessing areaofc0ncern. Addition- TheLTC@1562 filterblockis arranged asa 4th order produce ally,linearregulators littlenoiseenergy outside Butteruvorth lowpass. lts output is delivered viathe thisregion.l These considerations suggest a measure-330FF-1 00fihighpass network. Thecircuit's outputdrives mentbandpass of10Hzto 100kHz, withsteep slopes atthe a thermally responding RMSvoltmeter.3 Notethatall bandlimits.Figure 2 showsa conceptual filterfor LDO circuitpower isfurnished precluding ground bybatteries, noisetesting. TheButtenrvorth sections arethekeyto loops fromcorrupting themeasurement. steep slopes andflatness inthepassband. Thesmallinput Nole1: Switching regulators areanentirely proposition, ditferent gaintoprovide levelrequires 60dBoflownoise adequate requiring verybroadband noisemeasurement. fortheButtenruorth signal filters.Figure choice fortheregulator, 3details thefilter l,lote2: Component morecritical thanmight be supposed, is discussed "Capacitor in Selection Considerations." Theregulator scheme. under testis at thediagram's 3: Thechoice oftheRMSvoltmeter isabsolutely crucial to gainhighpass center.2 A1-A3make upa60dB section. A1 Note obtaining meaningful measurements. SeeAppendix C,Application andA2,extremely lownoise (<1nvrffi1,comprise Note83"Understanding devices andSelecting RMSVoltmeters." Figute 2.FillerStructure forNoise Testing LD0s. Butterworth Sections Provide Appropriate Response in Desired Frequency Range Intormationfurnishedby LinearTechnology corporationis believedt0 be accurateand reliable. However, noresponsibility is assumed f0r its use.LinearTechnology Corporation makesno rcpresen- 6 _l DEMCMANUALDC367 LOWDROPOUT REGULATOR OP€RRTION 1OpF I WPICAL REGUI.ATOR UNDER TEST .I% ALLRESISTORS MFrAL FILM 4.7pFCAPACITORS = MYLAR, W|MAMKS-2 330pF = SANY0 CAPACITOHS 0SC0N T4.5V DERIVED FROM 6AAcELLs POWER REGULATOR FROM APPROPRIATE NUMEER OFDSIZE BATTERIES 10k LTCl562 INV8 INVC VlB VlC v28 vzc v-' \i+ v-' | ; 330pF I rr I 100f,t OUTPUT TOTHERMALLY RESPONDING RMSVOLTMEIER 0.1VFULL = 100r.rVnus SCALE NO|SE 10Hz T0100kHz BW ;l fMr- v- SHDN AGNO v-. v-' v2A V20 V1A V1D INVA INVD F.igure 3. lmplementation Figure 2. LowNoise .G PACKAGE PINS4, 7, 14,17ARE SUBSTRATVSHIELD CONNECTIONS ANDMUST BETIED TOV- provide Amplifiers Gainandlnitial -0I Highpass shaping' LTc1562 riitersuppiiis +t'irru.iauftr*;;tiLilasscharacteristic DEMOMANUALDC367 LOWDROPOUT REGULATOR PCBTRYOUT RNDflTM i.Zffi'ffi,.lfie#!-bi,ll 011 a p3;1l.J,llfi 1..?i :S.:H t-_ RJFlt Et ffi--JPi-Rd ;t cz uI cr ttFln r--.1 llUU l_J+t E1 GND =EE o ll{ I I- a o E2 sTET -r r== o DCJ67ALT1963ES8 I.5A L()TDROPOUT REGULAIOR a Silkscreen Top Solder Mask Top Layer 1, Component Side Layer2, GNDPlane. Paste Mask Top Layer 3, GN[lplane. I o a a ....*. o Layer 4, Solder Side* - o I aaaaaaa a Solder MaskBottom - These layers areshorted toL1withviasandfunction asheatdispersants. {7L=|JlsnR DEMOMANUALDC367 LOWDROPOUT REGULATOR PCFRBDRRUNG l-'*-l N0TES: UNLESS OTHERWISE SPECIFIED 1.MATERIAL: FR40RE0UIVALENT EPOXY, 2 02.COppER CLAD THICKNESS 0.062r 0.006ToTAL 0F4 r-AyERS. 2.FINISH: ALLPUTED HOLES 0.001 MIN/0.001SMM COppER PLATE ELECTRODEPOSITEO TIME.LEAD COMPOSITION (SMOBC) BEFORE REFLOW, SOLDER MASK OVER BARE COPPER 3.S0LDER MASK: BOTH SIDES USING LPt0REOU|VALENT. 4.SILKSCREEN: USING WHITE NON-C0NDUCT|VE Ep0XytNK. 5. UNUSED SMDCOMPONENTS SHOULD BEFREE OFSOLDER. 6. FILLUPALLVIAS WITH SOLDER. 7.SCORING: DO .A OC OC A .: A oc ? -B o 2.00 oc I I __l Linear Technology Corporation 1630McCarthy Blvd., Mitpitas, CA95035-7417 /,ln8\ 432-1qnn . FAY' /dn8l fid-nsn7 . uamr linarr nnm NUMBER YMBOLDIAMEIEROFHOLES TEO 0.02 za B 0.035 z YES 0.064 YES inr-0.07 z TEDINUSA 17Lrn$P i='Crir.ro-roor- ,='t