LD7516C 08/31/2016. Primary Side Quasi-Resonant Controller. Features. General Description. Applications. Typical Application REV.

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1 REV. 01 General Descripion Primary ide Quasi-Resonan Conroller The is an excellen primary side feedback MO 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. Typical Applicaion Operaing in CV/CC Mode Feaures Primary-ide Feedback Conrol wih Quasi-Resonan Operaion 120mA/-200mA unbalanced MO driving capabiliy Consan Volage wihin 5% Buil-In Adjusable Load Regulaion Compensaion Consan Curren Conrol Ulra-Low arup Curren (<1.5A) 0.65mA Low Operaing Curren a Ligh Load 75 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 AC Inpu EMI Filer DC Oupu COMP VCC GND -D-01 Augus

2 Pin Configuraion OT-26 (TOP VIEW) COMP C YWP pp VCC GND YY, Y : Year code (D: 2004, E: ) WW, W : Week code PP : Producion code P16C : Ordering Informaion Par number Package Top Mark hipping GL OT-26 YWP/16C 3000 / ape & reel The is ROH complian/green Packaged Proecion Mode Pin Descripions Par number VCC_OVP _UVP OTP(Inernal) Auo-Resar Auo-Resar Auo-Resar PIN NAME FUNCTION 1 VCC upply volage pin. 2 GND Ground. 3 Auxiliary volage sense and Quasi Resonan deecion. 4 Curren sense pin, connec o sense he wich curren. 5 COMP Oupu of he error amplifier for volage compensaion. 6 Gae drive oupu o drive he exernal MO wich. -D-01 Augus

3 Block Diagram VCC UVLO On/Off VCC OVP LDO PG Proecion Gae Driver Ou Inernal upply Max. Fsw and Green Mode PWM Logic Proecion COMP Load Compensaion Vref GM V COMP CV Conrol V COMP /H UVP Proecion CC compensaion QRD CC Conrol Open Proecion LEB + - In. OTP GND -D-01 Augus

4 Absolue Maximum Raings upply Volage VCC, -0.3V ~ 40V -0.3V ~ VCC+0.3V COMP,, -0.3V ~ 4.0V (AC curren 3mA) -0.7V ~ 4.0V Maximum Juncion Temperaure 150C orage Temperaure Range -65C o 150C Package Thermal Resisance (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 Raings may damage he device. Maximum Raings are sress raings only. Funcional operaion above he Recommended Operaing Condiions is no implied. Exended exposure o sress above Recommended Operaing Condiions may affec device reliabiliy Recommended Operaing Condiions Iem Min. Max. Uni Operaing Juncion Temperaure C upply VCC Volage V VCC Capacior F ar-up resisor Value (AC ide, Half Wave) 1M 6.6M Comp Pin Capacior 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-01 Augus

5 Elecrical Characerisics (T A = +25C unless oherwise saed, V CC =12.0V) PARAMETER CONDITION YM. MIN TYP MAX UNIT upply Volage (Vcc Pin) arup Curren VCC=UVLO-ON-0.05V I CC_T A Operaing Curren V COMP=0V, =open, =2V I CC_OP ma OVP/ UVP ripped, =0V I CC_OPA ma UVLO (off) V CC_OFF V UVLO (on) V CC_ON V Vcc OVP Level V CC_OVP V Error Amplifier (COMP pin) Reference Volage, V REF V REF V Oupu ink Curren V = 1.3V, V COMP=2V* I COMP_INK2 10 A Oupu ource Curren V = 0.7V, V COMP=2V* I COMP_OURCE2 10 A Load Compensaion Curren V COMP=2.5V I LOAD_COMP A Curren ensing ( Pin) Maximum Inpu Volage V _MAX V Minimum V -OFF V COMP < 0.45V V _MIN mv Leading Edge Blanking Time * T LEB ns CC Compensaion Curren V COMP>0.9V I CC 300 A Oscillaor for wiching Frequency Maximum Frequency F W_MAX khz Green Mode Frequency * F W_GREEN 25 khz Minimum Frequency F W_MIN khz Maximum On Time T ON_MAX 18 s Feedback (Quasi Resonan Deecion, Pin) QRD Trip Level * V QRD 150 mv Hyseresis * V QRD_HY 50 mv Under Volage Proecion (UVP, Pin) Under Volage Level V _UVP V UVP Delay Time A sar-up* T D_UVP_ 20 ms On Chip OTP (Over Temperaure) OTP Level * T INOTP 140 C OTP Hyseresis * T INOTP_HY 15 C *: Guaraneed by design. -D-01 Augus

6 Typical Performance Characerisics VCC-ON (V) VCC-OFF (V) Temperaure (C) Fig. 1 UVLO (on) vs. Temperaure Temperaure (C) Fig. 2 UVLO (off ) vs. Temperaure ICC-T (A) FW-MAX (KHz) Temperaure (C) Fig. 3 arup Curren vs. Temperaure Temperaure (C) Fig. 4 Max Frequency vs. Temperaure FW-GREEN (KHz) FW-MIN (KHz) Temperaure (C) 0.4 Temperaure (C) Fig. 5 Green Mode Frequency vs. Temperaure Fig. 6 Min Frequency vs. Temperaure -D-01 Augus

7 Y Axis Tile X Axis Tile X Axis Tile VREF (V) ILoad Comp (A) Temperaure (C) 0 Temperaure (C) Fig. 7 Reference Volage vs. Temperaure Fig. 8 Load Compensaion vs. Temperaure V-MAX (V) VCC-OVP (V) Temperaure (C) Fig. 9 V (off) vs. Temperaure 26 Temperaure (C) Fig. 10 VCC OVP vs. Temperaure -D-01 Augus

8 Applicaion Informaion Operaion Overview The is an excellen primary side feedback conroller wih Quasi-Resonan 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 MO. As shown in Fig. 11, 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. 12. A sarup ransien, he VCC is below he UVLO(on) hreshold, so here s no pulse delivered ou from o drive he power MO. Therefore, he curren hrough R1 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 R1 and hen reduce he power consumpion on R1. By using CMO process and some unique circui design, he requires only 1.9A max o sar up. Higher resisance of R1 will spend much more ime o sar up. The user is recommended o selec proper value of R1 and C1 o opimize he power consumpion and sarup ime. UVLO(on) Vcc AC Inpu EMI Filer UVLO(off) Cbulk D1 R1 C1 I(Vcc) operaing curren (~ ma) VCC sarup curren (~µa) GND Fig. 11 Fig. 12 -D-01 Augus

9 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. 13. The volage induced in he auxiliary winding is a reflecion of he secondary winding volage while he MO 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 Ra Rb V REF + - /H COMP Driver secondary curren discharge ime from previous cycle. And will be hold unil he nex sampling period. The Fig. 13 sampled volage is compared wih an inernal reference V REF (1.0V) and he error will be amplified. The error amplifier oupu COMP reflecs he load condiion and V D 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: V Ra Ns 1.0V (1 )( ) Rb Na V F V D Fig.14 Where V F indicaes he drop volage of he oupu diode, Ra and Rb are op and boom feedback resisor value, Ns and Na are he urns of ransformer secondary and auxiliary. The undershoo would make he sample error. In case ha he oupu volage is sensed hrough he auxiliary winding; he leakage inducance will induce ringing o affec oupu regulaion. To opimize he collecor volage clamp circui will minimize he high frequency ringing and achieve he bes regulaion. Fig. 14 VIN Na Fig.15 R Np Ns shows he desired collecor volage waveform in compare o hose wih large undershoo due o leakage inducance induced ring (Fig. 15). The ringing may make he sample error and cause poor performance for oupu volage Ra COMP regulaion. A proper selecion for resisor R, in series Rb wih he clamp diode, may reduce any large undershoo, as shown in Fig. 16. Fig.16 -D-01 Augus

10 Load Regulaion 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. 17. 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 Load_COMP (V COMP 0.45) 9.75( A) The compensaion curren versus V COMP is shown as: 20 I Load_COMP (ma ) Fig. 17 Quasi-Resonan Mode Deecion V COMP (V) The employs quasi-resonan (QR) 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. 18 shows he ypical QR deecion block. The QR deecion block will deec auxiliary winding signal o drive MO as pin volage drops o 0.15V. The QR comparaor will no acivae if pin volage remains above 0.2V. Naux Ra Rb 1.0V ample and Hold 0.15/0.2 V Max. Frequency & Green Mode GM VCOMP Error Amplifier /H Buffer 2R R Load Compensaion QRD QRD Muli-Mode Operaion Blanking Time QRD Time-Ou 2 Time-Ou 1 Fig. 18 C.C. 1V PWM Turn-on Turn-off Leading Edge Blanking The is a QR conroller operaing in muli-modes. The conroller changes operaion modes according o line volage and load condiions. A heavy-load (V COMP>1.6V, Fig. 19), 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 75 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 QR mode. A medium or ligh load condiions (0.7V<V COMP<1.2V), 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. R Q -D-01 Augus

11 fs 75kHz VIN Np Ns 0.7kHz 25kHz Green Mode 0.3V 0.7V 1.2V 1.6V Disconinuous wih valley swiching (2 nd,3 rd,4 h... Valley) Quasi Resonan (Firs Valley) Vcomp Fig. 19 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. 20, he deecs he primary MO 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 0.8V. From above, he MO peak curren can be obained from below. I PEAK(MAX) 0.8V R A leading-edge blanking (LEB) ime is included in he inpu of pin o preven he false-rigger from he urn-on curren spike. delivers more consan curren a high inpu volage han a low inpu volage. To compensae i, an offse volage is added o he R signal by an inernal curren source (I CC) and an exernal resisor (R 1) in series beween he sense resisor (Rs) and he pin, By selecing a proper value of he resisor in series wih he pin, he amoun of compensaion can be adjused. The value of I CC (300 μ A) depends on he COMP volage(v COMP>1.2V). The equaion of I CC (300μA) is decreased as: V V 300A R ) ( 1 Ra Rb Na COMP V Fig. 20 Principle of C.C. Operaion R1 V R LEB ime 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. 21. 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 R T Ts DI 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 Io N N N N P P V R 1 R 1 3 DI T T However his is an approximae equaion. The user may fine-une i according o he experimen resul. DI -D-01 Augus

12 Ou UVP funcion in is an auo-recovery ype i P T ON T i P,PK T DI proecion. The Fig. 23 shows is operaion. During he sof sar period, he UVP is disabled. To avoid oupu over volage in sof sar period. The Fig. 24 shows he operaion. While is shor o GND, pin keeps in zero volage level. If canno deec any volage signal over i,pk i 0.15V in he beginning of sof sar period, hen he sof sar will urn o generae a driving signal every 4ms unil Fig. 21 UVP delay o shu down IC and auo recovery. OVP (Over Volage Proecion) on Vcc Auo Recovery Vcc is implemened wih OVP funcion hrough Vcc. As he Vcc volage rises over he OVP hreshold volage, UVLO(on) UVLO(off) he oupu drive circui will be shu off simulaneously hus o sop he swiching of he power MO unil he nex UVLO(on) arrives. The Vcc OVP funcion of is UVP Tripped an auo-recovery ype proecion. The Fig. 22 shows is UVP Level operaion. Tha is, if he OVP condiion is removed, i will resume o normal oupu volage and Vcc level in normal condiion. UVP Delay Time of ar + UVP Delay Time VCC OVP Level OVP Tripped wiching Non-wiching wiching UVLO(on) UVLO(off) Fig. 23 Vcc UVLO(on) UVLO(off) wiching Non-wiching Fig. 22 wiching hor Level hor Under Volage Proecion ( UVP) & hor Circui Proecion Auo Recovery of ar + UVP Delay Time Non- wiching is implemened wih an UVP funcion over pin. If he volage falls below UVP level over he delay ime, he proecion will be acivaed o sop he swiching of he power MO unil he nex UVLO(on) arrives. The Fig. 24 -D-01 Augus

13 Package Informaion OT-26 ymbol Dimension in Millimeers Dimensions in Inches Min Max Min Max A B C D F 0.95 TYP TYP H I J M θ 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-01 Augus

14 Revision Hisory REV. Dae Change Noice 00 06/05/2015 Original pecificaion Modified I LOAD_COMP (was I ) es condiion from V COMP=3.0V o 2.5V, and revise he applicaion noe I LOAD_COMP equaion and V COMP V I LOAD_COMP curve (Fig.17), due o mark error. The field ess sill he same. 2. Modified F W_MIN from 0.56 khz o 0.5 khz, due o mark error. The field ess sill he same. -D-01 Augus

LD7515L 8/5/2015. Primary Side Quasi-Resonant BJT Controller with CV/CC Operation. Features. General Description. Applications. Typical Application

LD7515L 8/5/2015. Primary Side Quasi-Resonant BJT Controller with CV/CC Operation. Features. General Description. Applications. Typical Application 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.