Primary ide Quasi-esonan BJT Conroller wih CV/CC Operaion EV. 00 General Descripion The is an excellen primary side feedback BJT conroller wih CV/CC operaion, inegraed wih several funcions of proecions. I minimizes he componen couns and is available in a iny OT-26 package. Those make i an ideal design for low cos applicaions. I provides funcions of ulra-low sarup curren, green-mode power-saving operaion and leading-edge blanking of he curren sensing. Also, he feaures Inernal OTP (Over Temperaure Proecion) and OVP (Over Volage Proecion) o preven he circui from being damaged due o abnormal condiions. In mos cases, he power supply wih primary-side feedback conroller would accompany wih some serious load regulaion effec. To deal wih his problem, he consiss of dedicaed load regulaion compensaion circui o enhance is performance. Feaures Primary-ide Feedback Conrol wih Quasi-esonan Operaion Direc Drive of BJT wich Consan Volage wihin 5% Buil-In Adjusable Load egulaion Compensaion Consan Curren Conrol Ulra-Low arup Curren (<1.9A) 0.5mA Low Operaing Curren a Ligh Load 60 khz Maximum wiching Frequency. Curren Mode Conrol Green Mode Conrol Improve Efficiency LEB (Leading-Edge Blanking) on Pin Buil-in of ar VCC OVP (Over Volage Proecion) Pin Open/hor Proecion Inernal OTP (Over Temperaure Proecion) Applicaions Mobile Phone Adaper Lower Power AC/DC Adaper Typical Applicaion AC Inpu AC Inpu EMI Filer COMP VCC GND -D-00 Augus 2015 1
Pin Configuraion OT-26 (TOP VIEW) COMP 6 5 4 15L YWP pp 1 2 3 VCC GND YY, Y : Year code (D: 2004, E: 2005..) WW, W : Week code PP : Producion code P15L : Ordering Informaion Par number Package Top Mark hipping GL OT-26 YWP/15L 3000 / ape & reel The is OH complian/green Packaged Pin Descripions PIN NAME FUNCTION 1 VCC upply volage pin. 2 GND Ground. 3 Auxiliary volage sense and Quasi esonan deecion. 4 Curren sense pin, connec o sense he wich curren. 5 COMP Oupu of he error amplifier for volage compensaion. 6 Base drive oupu o drive he exernal BJT wich. -D-00 Augus 2015 2
Block Diagram VCC 13 V 4 V UVLO Comparaor inernal bias & Vref 18V OVP OVP Comparaor VCC OK Vref OK VCC PG Inernal OTP Proecion OVP Base Driver Max. Frequency & Green Mode COMP 2.0V GM Blanking Time QD V COMP Time-Ou 2 Error Amplifier Buffer QD 2 Time-Ou 1 C.C. 1V PWM Comparaor Q ample and Hold /H Leading Edge Blanking Load Compensaion C.C. QD CC Conrol QD 0.1V/0.2V /H 1.0V Delay Couner Q Proecion UVP PG Q GND -D-00 Augus 2015 3
Absolue Maximum aings upply Volage VCC, 20V -0.3V ~3.3V COMP,, -0.3V ~3.3V (AC curren 3mA -0.7V ~ 3.3V Maximum Juncion Temperaure 150C orage Temperaure ange -65C o 150C Package Thermal esisance (OT-26,θ JA) 200C/W Power Dissipaion (OT-26, a Ambien Temperaure = 85C) 200mW Lead emperaure (oldering, 10sec) 260C ED Volage Proecion, Human Body Model 2.5 KV ED Volage Proecion, Machine Model 250 V Cauion: ress exceeding Maximum aings may damage he device. Maximum aings are sress raings only. Funcional operaion above he ecommended Operaing Condiions is no implied. Exended exposure o sress above ecommended Operaing Condiions may affec device reliabiliy ecommended Operaing Condiions Iem Min. Max. Uni Operaing Juncion Temperaure -40 110 C upply VCC Volage 5.5 16 V VCC Capacior 2.2 10 F ar-up resisor Value (AC ide, Half Wave) 1M 6.6M Comp Pin Capacior 470 4700 pf Noe: 1. I s essenial o connec VCC pin wih a MD ceramic capacior (0.1F~0.47F) o filer ou he undesired swiching noise for sable operaion. This capacior should be placed close o IC pin as possible 2. Connecing a capacior o COMP pin is also essenial o filer ou he undesired swiching noise for sable operaion. 3. The small signal componens should be placed close o IC pin as possible. -D-00 Augus 2015 4
Elecrical Characerisics (T A = +25C unless oherwise saed, V CC =12.0V) PAAMETE CONDITION YM. MIN TYP MAX UNIT upply Volage (Vcc Pin) arup Curren VCC=UVLO-ON-0.05V I CC_T 1.0 1.9 A Operaing Curren V COMP=0V, =open, =2V I CC_OP2 0.5 ma OVP/ UVP ripped, =0V I CC_OPA 0.18 0.25 0.32 ma UVLO (off) V CC_OFF 3.4 4.0 4.6 V UVLO (on) V CC_ON 12 13 14 V Vcc OVP Level V CC_OVP 17 18 19 V Error Amplifier (COMP pin) eference Volage, V EF V EF 1.97 2.00 2.03 V Oupu ink Curren V = V EF+0.05, V COMP=2V* I COMP_INK1-4 A Oupu ource Curren V = Vref-0.05V, V COMP=2V* I COMP_OUCE1 4 A Oupu Upper Clamp Volage V =1.0V * V COMP_CLAMP 3 V Load Compensaion Curren V COMP=3V I LOAD COMP 17 20 23 A Curren ensing ( Pin) Maximum Inpu Volage V _MAX 0.93 1 1.07 V Minimum V -OFF V COMP < 0.45V* V _MIN 150 175 195 mv Leading Edge Blanking Time * T LEB 430 600 770 ns Oscillaor for wiching Frequency Maximum Frequency F W_MAX 54.5 60 65.5 khz Green Mode Frequency * F W_GEEN 25 khz Minimum Frequency F W_MIN 0.6 0.8 1.0 khz Maximum On Time T ON_MAX 11 16 21 s Oupu Drive ( Pin) Max. Oupu Base Curren V=1V I B_MAX 54 62 69 ma Under Volage Proecion (UVP, Pin) Under Volage Level V _UVP 0.9 1.0 1.1 V UVP Delay Time A sar-up* T D_UVP_ 20 ms On Chip OTP (Over Temperaure) OTP Level ** T INOTP 115 130 145 C OTP Hyseresis * T INOTP_HY 30 C *: Guaraneed by design. **: For reference only, parameer verified in design phase. -D-00 Augus 2015 5
Typical Performance Characerisics 15.0 6.0 14.0 5.0 VCC-ON (V) 13.0 12.0 VCC-OFF (V) 4.0 3.0 11.0 2.0 10.0 Fig. 1 UVLO (on) vs. Temperaure 1.0-40 0 40 80 120 125 Fig. 2 UVLO (off ) vs. Temperaure 2.0 70 1.5 65 ICC-T (A) 1.0 0.5 FW-MAX (KHz) 60 55 0.0 50 Fig. 3 arup Curren vs. Temperaure 45-40 0 40 80 120 125 Fig. 4 Max Frequency vs. Temperaure 29 1.0 27 0.9 FW-GEEN (KHz) 25 23 FW-MIN (KHz) 0.8 0.7 21 0.6 19 0.5 Fig. 5 Green Mode Frequency vs. Temperaure Fig. 6 Min Frequency vs. Temperaure -D-00 Augus 2015 6
Y Axis Tile 15 12 12 99 2.02 66 3 3 0-40 0-20 0 20 40 60 80 100 120-40 -20 0 20 40 X Axis Tile 60 80 100 120 X Axis Tile 30 2.01 25 VEF (V) 2.00 1.99 ILoad Comp (A) 20 15 10 1.98 5 1.97 0 Fig. 7 eference Volage vs. Temperaure Fig. 8 Load Compensaion vs. Temperaure 1.04 20 1.02 19 V-MAX (V) 1.00 0.98 VCC-OVP (V) 18 17 0.96 16 0.94 4.5 Fig. 9 V (off) vs. Temperaure 15 Fig. 10 VCC OVP vs. Temperaure 80 3.5 70 -L () 2.5 1.5 IB-MAX (ma) 60 50 0.5 40 Fig. 11 Oupu Low ON-resisance vs. Temperaure 30 Fig. 12 Max. Oupu Base Curren vs. Temperaure -D-00 Augus 2015 7
Applicaion Informaion Operaion Overview The is an excellen primary side feedback conroller wih Quasi-esonan operaion o provide high efficiency. The removes he need for secondary feedback circuis while achieving excellen line and load regulaion. I mees he green-power requiremen and is inended for he use in hose modern swiching power suppliers and linear adapors ha demand higher power efficiency and power-saving. I inegraes wih more funcions o reduce he exernal componens couns and he size. Major feaures are described as below. Under Volage Lockou (UVLO) An UVLO comparaor is implemened in i o deec he volage across VCC pin. I would assure he supply volage enough o urn on he and furher o drive he power BJT. As shown in Fig. 13, a hyseresis is buil in o preven shudown from volage dip during sarup. arup Curren and arup Circui The ypical sarup circui o generae VCC of he is shown in Fig. 14. A sarup ransien, he VCC is below he UVLO(on) hreshold, so here s no pulse delivered ou from o drive he power BJT. Therefore, he curren hrough 1 will be used o charge he capacior C1. Unil he VCC is fully charged o deliver he drive-ou signal, he auxiliary winding of he ransformer will provide supply curren. Lower sarup curren requiremen on he PWM conroller will help o increase he value of 1 and hen reduce he power consumpion on 1. By using CMO process and some unique circui design, he requires only 1.9A max o sar up. Higher resisance of 1 will spend much more ime o sar up. The user is recommended o selec proper value of 1 and C1 o opimize he power consumpion and sarup ime. UVLO(on) Vcc AC inpu EMI Filer UVLO(off) Cbulk D1 1 C1 I(Vcc) operaing curren (~ ma) VCC sarup curren (~ua) GND Fig. 13 Fig. 14 -D-00 Augus 2015 8
Principle of CV Operaion V IN In he DCM flyback converer, i can sense he oupu Np Ns volage from auxiliary winding. samples he auxiliary winding on he primary-side o regulae he Na oupu volage, as shown in he Fig. 15. The volage induced in he auxiliary winding is a reflecion of he secondary winding volage while he BJT is in off sae. Via a resisor divider conneced beween he auxiliary winding and pin, he auxiliary volage is sampled afer he sample delay ime which is defined as 30~50% of a b V EF + - /H COMP Driver secondary curren discharge ime from previous cycle. And will be hold unil he nex sampling period. The Fig. 15 sampled volage is compared wih an inernal reference V EF (2.0V) and he error will be amplified. The error amplifier oupu COMP reflecs he load condiion and V ce The overshoo here is minor conrols he duy cycle o regulae he oupu volage, hus consan oupu volage can be achieved. The oupu volage is given as: a Ns V 2.0V(1 )( ) V F b Na Where V F indicaes he drop volage of he oupu diode, a and b are op and boom feedback resisor value, Ns and Na are he urns of ransformer secondary and auxiliary. V ce Fig.16 The undershoo would make he sample error. In case ha he oupu volage is sensed hrough he auxiliary winding; he leakage inducance will induce Fig.17 ringing o affec oupu regulaion. To opimize he collecor volage clamp circui will minimize he high frequency ringing and achieve he bes regulaion. Fig. 16 V IN Na Np Ns shows he desired collecor volage waveform in compare o hose wih large undershoo due o leakage inducance induced ring (Fig. 17). The ringing may make he sample a error and cause poor performance for oupu volage COMP regulaion. A proper selecion for resisor, in series b wih he clamp diode, may reduce any large undershoo, as shown in Fig. 18. Fig.18 -D-00 Augus 2015 9
Load egulaion Compensaion is implemened wih load regulaion compensaion o compensae he cable volage drop and o achieve a beer volage regulaion. The offse volage across is produced by he inernal sink curren source during he sampling period. The inernal sink curren source is proporional o he value of V COMP o compensae he cable loss as shown in Fig. 19. o, he offse volage will decrease as he V COMP decreases from full-load o no-load. I is programmable by adjusing he resisance of he volage divider o compensae he drop for cable lines used in various condiions. The equaion of inernal sink curren is shown as: I (V COMP 0.45) 7.85 ( A) The compensaion curren versus V COMP is shown as: 20 I (A) 0 0.45 3.0 Fig. 19 Quasi-esonan Mode Deecion V COMP (V) The employs quasi-resonan (Q) swiching scheme o swich in valley-mode eiher in CV or CC operaion. This will grealy reduce he swiching loss and he raio dv/d in he enire operaing range for he power supply. Fig. 20 shows he ypical Q deecion block. The Q deecion block will deec auxiliary winding signal o drive BJT as pin volage drops o 0.1V. The Q comparaor will no acivae if pin volage remains above 0.2V. Naux a b 2.0V ample and Hold 0.1/0.2 V Max. Frequency & Green Mode GM VCOMP Error Amplifier /H Buffer 2 Load Compensaion QD QD Muli-Mode Operaion Blanking Time QD Time-Ou 2 Time-Ou 1 Fig. 20 C.C. 1V PWM Turn-on Turn-off Leading Edge Blanking The is a Q conroller operaing in muli-modes. The conroller changes operaion modes according o line volage and load condiions. A heavy-load (V COMP>1.8V, Fig. 21), here migh be wo siuaions o mee. If he sysem AC inpu is in low line, he will urn on in firs valley. If in high line, he swiching frequency will increase ill over he limi of 60 khz and skip he firs valley o urn on in 2 nd, 3 rd.valley. The swiching frequency would vary depending on he line volage and he load condiions when he sysem is operaed in Q mode. A medium or ligh load condiions (0.7V<V COMP<1.4V), he frequency clamp is reduced o 25 khz maximum. However, he characerisic in valley swiching behaves well wihou problem in his condiion. The will urn on in 4 h, 5 h. valley. Tha is, when he load decreases, he sysem will auomaically skip some valleys and he swiching frequency is herefore reduced. A smooh frequency fold-back and high power efficiency are hen achieved. A zero load or very ligh load condiions (V COMP<0.3V), he sysem operaes in minimum frequency for power saving. The sysem modulaes he frequency according o he load and V COMP condiions. Q -D-00 Augus 2015 10
fs 0.8kHz 25kHz Green Mode 0.3V 0.7V 1.4V 1.8V 60kHz Disconinuous wih valley swiching (2 nd,3 rd,4 h... Valley) Fig. 21 Quasi esonan (Firs Valley) Vcomp Curren ensing and Leading-edge Blanking The ypical curren mode of PWM conroller feedbacks boh curren signal and volage signal o close he conrol loop and achieve regulaion. As shown in Fig. 22, he deecs he primary BJT curren from he pin, which is no only for he peak curren mode conrol bu also for he pulse-by-pulse curren limi. The maximum volage hreshold of he curren sensing pin is se a 1V. From above, he BJT peak curren can be obained from below. I PEAK(MAX) 1V A leading-edge blanking (LEB) ime is included in he inpu of pin o preven he false-rigger from he urn-on curren spike. Principle of C.C. Operaion The primary side conrol scheme is applied o eliminae secondary feedback circui or opo-coupler, which will reduce he sysem cos. The swiching waveforms are shown in Fig. 23. The oupu curren Io can be expressed as: 1 i Io 2,PK 1 N 2 N P 1 N 2 N P T T i DI P,PK V TDI Ts T T The primary peak curren (i P,PK), inducor curren discharge ime (T DI) and swiching period (T ) can be deeced by he IC. The raio of V *T DI/T will be modulaed as a consan (V *T DI/T =1/3). o ha I O can be obained as 1 N Io 2 N P 1 N 2 N P V 1 1 3 DI T T However his is an approximae equaion. The user may DI fine-une i according o he experimen resul. Ou T i P VIN Np Ns i P,PK Na T ON T DI i,pk i LEB ime a Fig. 23 COMP b Fig. 22 -D-00 Augus 2015 11
OVP (Over Volage Proecion) on Vcc Auo ecovery generae a driving signal every 4ms unil UVP delay o shu down IC and auo recovery. is implemened wih OVP funcion hrough Vcc. As he Vcc volage rises over he OVP hreshold volage, Vcc he oupu drive circui will be shu off simulaneously hus o sop he swiching of he power BJT unil he nex UVLO(on) arrives. The Vcc OVP funcion of is UVLO(on) UVLO(off) an auo-recovery ype proecion. The Fig. 24 shows is operaion. Tha is, if he OVP condiion is removed, i will resume o normal oupu volage and Vcc level in normal UVP Tripped condiion. UVP Level OVP Level VCC OVP Tripped UVP Delay Time of ar + UVP Delay Time UVLO(on) UVLO(off) wiching Non-wiching wiching Fig. 25 Vcc wiching Non-wiching wiching UVLO(on) UVLO(off) Fig. 24 Under Volage Proecion ( UVP) & hor Circui Proecion Auo ecovery is implemened wih an UVP funcion over pin. If he volage falls below 1.0V over he delay ime, he proecion will be acivaed o sop he swiching of he power BJT unil he nex UVLO(on) arrives. The UVP hor Level hor of ar + UVP Delay Time Non- wiching funcion in is an auo-recovery ype proecion. The Fig. 25 shows is operaion. The UVP is disabled during he sof sar period. During he sof sar period, he UVP is disabled. To avoid oupu over volage in Fig. 26 sof sar period. The Fig. 26 shows he operaion. While is shor o GND, pin keeps in zero volage level. If canno deec any volage signal over 0.2V in he beginning of sof sar period, hen he sof sar will urn o -D-00 Augus 2015 12
Package Informaion OT-26 ymbol Dimension in Millimeers Dimensions in Inches Min Max Min Max A 2.692 3.099 0.106 0.122 B 1.397 1.803 0.055 0.071 C ------- 1.450 ------- 0.057 D 0.300 0.500 0.012 0.020 F 0.95 TYP 0.037 TYP H 0.080 0.254 0.003 0.010 I 0.050 0.150 0.002 0.006 J 2.600 3.000 0.102 0.118 M 0.300 0.600 0.012 0.024 θ 0 10 0 10 Imporan Noice Leadrend Technology Corp. reserves he righ o make changes or correcions o is producs a any ime wihou noice. Cusomers should verify he daashees are curren and complee before placing order. -D-00 Augus 2015 13
evision Hisory EV. Dae Change Noice 00 08/05/2015 Original pecificaion. -D-00 Augus 2015 14