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| MP4653 real lips cc/ cv mode llc tv led driver MP4653 rev 1.0 1 www.monolithicpower.com 1 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. the future of analog ic technology descri ption the mp465 3 is a cc/cv mode l l c tv led driver for led backligh t ing, especially for larg e size tv le d backlight ing. powered by 9v to 30v input supplies, th e MP4653 outputs two 180 degree phase shifte d driving sig nals for the external power stages. its enhanced 9v gate driver provides adequa te driving capability an d can direct ly drive the external mosf et s through an external gate driving transformer. the mp46 53 integrat es a constant current control loop for the led current regulation and also a const ant voltage control loop for the dc bus voltage, which is used to generate system power supplies like 12 v/5v with other dc/dc converters. the cc/cv control loo p programs the operatin g frequency of the llc p o wer stage and thus reg ulates the l e d current and also the bus voltage. the MP4653 incorporat es both analog dimming and pwm dimming t o the led current. a driving sign al is outpu t to directly drive the dimming mosfet, whi c h help s to achieve fast and high co ntrast ratio pwm dimmi ng. the pwm dimming signal is also u s ed for the cc/cv mod e control. at pwm on interval, the cc mode is effect ive and the le d current is regulated; at pwm off i n terval, the cv mode is effective an d the dc b u s voltage is regulated. the gate d r iving signal and thus t he energy through the power stage are continu ous at both the pwm on interval a nd the pw m off interval. this helps t o eliminate t he system audible noise at pwm dimming. the mp46 53 features sufficient and smart protection t o increa se system reliability. it protects the fault condit i on at both t he dc bus stage and th e led driver stage. the protection for the dc bus stage include s the over voltage prot ection and over current protection (short protection). the protection for the l e d driver st age include s the open led protection, short led protection, over led current protection and a n y point of led string short to ground protectio n . thermal protection is integrated in MP4653. the mp465 3 is available in soic20 package. features ? secondary side ?real lips? llc controller ? cc/cv freq uency control loop ? audible noise elimination ? continuous driving sign al at pwm dimming and led fault condition ? 9v to 30v input voltage range ? analog and pwm di mming ? input under voltage lockout ? dc bus out put over vol t age protection ? dc bus sho r t protection ? system aut o -recovery a nd hiccup timer ? led open, short protection ? led output over voltage, over led current protection ? any point of led string short to gnd protection ? available in soic 20 pa ckage appli c ations ? lcd tvs and monitors ? desktop lcd flat panel displays ? flat panel video displays ? street lighting a l l m p s p a r t s a r e l e a d - f r e e a n d a d h e r e t o t h e r o h s d i r e c t i v e . for mp s gr een sta t u s , plea se v isit mps w ebsite under produ cts, quali t y assuran c e ? m p s ? and ?th e fu ture o f a nal og ic t e chn o l ogy ? ar e re gi ste r e d tr a dem ar ks o f monolithic pow e r sy st em s , inc. http://
mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 2 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. typical application vin pw m 400 v gnd 40 0 v ifb . . . ifb ovp pwmout pw mou t ocp 40 0 v g n d ocp ovp vocp vfb vocp vfb vbus vbus pwmout a- dim ifb vc c ss fs et gn d gl pwmout vin gr ss d pw min ic om p 4 5 6 7 8 9 10 13 14 15 16 11 12 vle d 1 vled 2 vled 4 vled 3 17 18 19 20 vf b vc omp 2 3 vocp 1 a- d i m mp 4 653 r ss_fset rss cs s r fs et r vcomp c vcomp r ic o m p c ic o m p c in c vcc c drv r vocp r ocp r vf bh r vfb l r ovph r ovpl r se nse c vb us c o c r mn mp q1 q2 t1 t2 c i mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 3 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. ordering information part number* package top marking MP4653gy soic20 MP4653 * for tap e & reel, ad d suf f ix ?z (eg. MP4653gy ? z); package reference ifb vcc ss fset g n d gl pw m o ut vin gr ssd pwmin ic omp 4 5 6 7 8 9 10 13 14 15 16 11 12 vled1 vled2 vled4 vled3 17 18 19 20 vfb vc om p 2 3 vocp 1 a- dim mp 4653 absolute m a xi mum ratings (1) supply voltage v in ......................... -0.3v to +38v gl,gr, vcc , pwmout ....................... -0.5v to 10.7v ssd, vocp ................................... -6.5v to + 4v other pins ....................................... -0.5v to +7v junction te mperature ............................... 150 ? c continuous power dissipation (t a = +25c) (2) ............................................................ 1.7 w storage temperature ............... -65 ? c to +150 ? c operating frequency .............................. 300khz recommended operating conditions (3) supply voltage v in ......................... -0.3v to +30v operating fr equency ................ 20khz to 25 0khz operating junction temp ....... -40 ? c to +125 ? c thermal resistance (4) ja jc soic20 .................................. 72 ...... 30 ... ? c/w notes : 1) exceeding these ratings ma y da m age the device. 2) the maximum allowable power dissipation is a function of the maximum junction temperature t j (max), the junction-to- ambient thermal resistance ja , and the ambient temperature t a . the maximum allowable continuous power dissipation at any ambient temperature is calculated by p d (max) = (t j (max)-t a )/ ja . exceeding the maximum allowable powe r dissipation w ill cause ex cessive die tempe r ature, and t h e regulator w ill g o into thermal shutdo w n . inte rnal thermal shutdo w n circuitr y pr otects the device from permanent damage. 3) the device is not guarante ed to fu nction outside of its operating conditions. 4) measured on jesd51-7, 4-layer pcb. mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 4 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. electri c al characteristi cs v in = 12v, t a = +25 ? c, unless otherw ise noted . parameter sy mbol conditio n min t y p max u nits gate driver gl, gr gate pull- do wn r gd igate = 20ma 2 ? gate pull-up r gu igate = 20ma 7.5 ? output source curre n t i sour ce with 1nf loa d 1 [5] a output sink curre n t i sink with 1nf loa d 2 [5] a dead time t dead 600 750 900 ns gate driver supply voltage (vcc) i vcc =0ma 9 9.4 9.8 v voltage v vcc i vcc =30ma 8.8 9.3 v cur r e n t i vcc 20 50 ma vin uvlo threshold v th_uvlo_vin vcc rising 4.2 4.35 4.5 v vcc uv lo h y stere s is v t h _vin_h y st 240 mv brightness dimming control range analog di mm ing full scal e v a-dim analog dimmi ng 1.13 1.18 1.23 v pwm logi c input threshold v th-pwm pwm dimming 1.6 1.9 2.2 v pwm logi c input hyste r e s is v t h-p w m -hy st pwm dimmin g 0.5 v supply current supply cu rre nt i in no drive r out put 1.6 2.5 m a operating frequency minimum fre quen cy set voltage v fset 0.95 1 1.05 v ss pin voltage vss at normal op eration 1.45 1.49 1.53 v minimum op e r ating fre que ncy f min_op rfset=r ss_fset =40 k ? , ifb=0.1v(icomp=2.2v), pwmin=high 35.6 38.6 41.6 khz maximum op erating f r eq u ency f max_op rfset=r ss_fset =40 k ? ,, ifb=0.21v(icomp=1v), pwmin=high 2.2 2.5 2.8 fmin outpu t pwm dimming signal for led (pwmout) logi c hig h voltage v h-pwmout normal operation 9v 9.4 9.8 v logi c lo w voltage v l-pwmout at fault condition, or pwmin=0 0.3 v output pwm source curre n t i sour ce_pw m out 100pf o n pwmout pi n 5 ma output pwm sink cu rrent i sink_ p w m out 100pf o n pwmout pi n 100 ma led cur r en t feedba ck (i fb) magnitud e |v ifb | 0.192 0.2 0.208 v led sho r t thresh ol d for immediate a c tion v ifbs 540 600 660 mv led sh ort det ection bl anking time t blank 100 140 180 ns mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 5 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. electri c al characteristi cs (continued) v in = 12v, t a = +25 ? c, unless otherw ise noted . parameter sy mbol conditio n min t y p max u nits led sho r t threshold fo r sl ow action v ifbsc 270 300 330 mv delay time for slow action t delay_ifb 300mv mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 7 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. typical characteristics i_in(ma) vin_bv( v) supply current vs. t emperature v uvlo_rising vs. t emperature v cc vs. t emperature i vcc =30ma dead time vs. temperature v uvlo_falling vs. t emperature v cc _30ma( v) char_uvlo_f( v) vcc voltage (v) load current (ma) vcc load regulation v in =12v vcc line regulation i vcc =20ma input voltage (v) input voltage (v) ifb v oltage line regulation 99.0 99.5 100.0 100.5 101.0 51 0 1 5 2 0 2 5 3 0 8.0 8.2 8.4 8.6 8.8 9.0 9.2 9.4 0 1 02 0 3 04 0 5 06 0 0 1 2 3 4 5 6 7 8 9 10 51 0 15 20 25 30 vcc vol t age (v) 0 10 20 30 40 50 60 -50 -30 -10 10 30 50 70 90 1 10 130 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 -50 -30 -10 10 30 50 70 90 1 10 130 char_uvlo_r( v) 9.10 9.15 9.20 9.25 9.30 9.35 9.40 -50 -30 -10 10 30 50 70 90 1 10 130 700 720 740 760 780 800 820 840 -50 -30 -10 10 30 50 70 90 110 130 t_dead(ns) 4.3 4.31 4. 3 2 4. 3 3 4. 3 4 4. 3 5 4. 3 6 4. 37 4. 3 8 4. 3 9 4. 4 -5 0 - 3 0 - 1 0 1 0 3 0 5 0 7 0 9 0 1 1 0 1 3 0 4 4.02 4.04 4.06 4.08 4.1 4.12 4.14 4.16 4.18 -50 -30 -10 10 30 50 70 90 1 10 130 mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 8 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. typical characteristics (continued) v_icomp_clamph( v) v_icomp_clampl( v) v_ifb( v) v ifb vs. t emperature v a-dim vs. t emperature v icomp_clamph vs. temperature v icomp_clampl vs. t emperature v vfb_clamp_h vs. t emperature r vled vs. temperature v vfb_clamp_l vs. t emperature vclamp_vfb_h( v) vclamp_vfb_l( v) v_ss( v) vss vs. temperature 1.482 1.484 1.486 1.488 1.490 1.492 1.494 1.496 1.498 1.500 1.502 -50 -30 -10 10 30 50 70 90 1 10 130 0.200 0.200 0.200 0.201 0.201 0.201 0.201 0.201 0.202 0.202 0.202 -50 -30 -10 10 30 50 70 90 1 10 130 1.184 1.185 1.186 1.187 1.188 1.189 1.190 1.191 1.192 -50 -30 -10 10 30 50 70 90 1 10 130 v a-dimh( v) 0.990 0.992 0.994 0.996 0.998 1.000 1.002 -50 -30 -10 10 30 50 70 90 1 10 130 2.180 2.185 2.190 2.195 2.200 2.205 2.210 2.215 2.220 -50 -30 -10 10 30 50 70 90 1 10 130 37.6 37.7 37.8 37.9 38.0 38.1 38.2 38.3 -50 -30 -10 10 30 50 70 90 1 10 130 fmin_op_cv(khz) 1.188 1.190 1.192 1.194 1.196 1.198 1.200 1.202 1.204 -50 -30 -10 10 30 50 70 90 1 10 130 1.985 1.990 1.995 2.000 2.005 2.010 2.015 2.020 -50 -30 -10 10 30 50 70 90 1 10 130 0 5 10 15 20 25 30 35 -50 -30 -10 10 30 50 70 90 1 10 130 r_led_in(kohm) mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 9 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. typical characteristics (continued) v_vocp_ocp( v) v_ssd( v) v ssd vs. temperature v vfb_ovp vs. temperature v vocp_ocp vs. t emperature char_led1_ovp( v) v vled_ovp vs. temperature 2.370 2.375 2.380 2.385 2.390 2.395 2.400 2.405 2.410 2.415 2.420 2.425 -50 -30 -10 10 30 50 70 90 1 10 130 -0.21 -0.20 -0.19 -0.18 -0.17 -0.16 -0.15 -50 -30 -10 10 30 50 70 90 1 10 130 2.36 2.37 2.38 2.39 2.40 2.41 2.42 2.43 -50 -30 -10 10 30 50 70 90 1 10 130 v_vfb_ovp( v) -0.1 10 -0.105 -0.100 -0.095 -0.090 -0.085 -0.080 -50 -30 -10 10 30 50 70 90 1 10 130 mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 10 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. typical perfo r manc e characteristics (continued) performanc e w aveforms are tested on the evaluation board of the design example section. v in = 12v, 400v_bus=380v, v led = 120v, iled=130ma*4 strings, dc/dc output=12v/1.5a, t a = 25c, unless otherwise noted. led current (ma) vin (v) pwm dimming curve analog dimming curve efficiency vs. v400v_bus adim voltage (v) 90.7 90.8 90.8 90.9 90.9 91.0 91.0 91.1 91.1 91.2 360 365 370 375 380 385 390 395 400 0 100 200 300 400 500 600 0 20 40 60 80 100 120 0 100 200 300 400 500 600 0 0.2 0.4 0.6 0.8 1 1.2 1.4 led current (ma) mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 11 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. typical perfo r manc e characteristics (continued) performance waveforms are tested on the evaluation board of the design example section. v in = 12v, 400v_bus=380v, v led = 120v, iled=130ma*4 strings, dc/dc output=12v/1.5a, t a = 25c, unless otherwise noted. start up with cv mode start up with cc mode shut down at cv mode shut down at cc mode steady state pwm dimming, 50%, 480hz analog dimming adim=0.655v pwm dimming+ analog dimming 12v output 10v/div . v bus 10v/div. v gr 5v/div . v in_ic 10v/div . v gl 5v/div . v bus 10v/div . v fset 1v/div . i led 200ma/div . v gl 5v/div . v bus 5v/div . v fset 1v/div . i led 200ma/div . v gl 5v/div . v bus 5v/div . v fset 500mv/div . i led 200ma/div . v gl 5v/div . v bus 5v/div . v fset 500mv/div . i led 200ma/div . v gl 5v/div . v gl 5v/div . v bus 5v/div . v bus 5v/div . v fset 500mv/div . v open 50v/div . i led 200ma/div . v icomp 1v/div . v gl 5v/div . v bus 5v/div . v fset 500mv/div . i led 200ma/div . v gl 5v/div . v bus 5v/div . v fset 500mv/div . i pri 1a/div . open led protection mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 12 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. typical perfo r manc e characteristics (continued) performance waveforms are tested on the evaluation board of the design example section. v in = 12v, 400v_bus=380v, v led = 120v, iled=130ma*4 strings, dc/dc output=12v/1.5a, t a = 25c, unless otherwise noted. open led protection recovery short led+ to led- protection short led+ to led- recover short led- to gnd protection short led- to gnd recover short led+ to gnd protection and recovery short dc bus to gnd protection and recover v ssd 100mv/div . i shor t 500ma/div . v gl 5v/div . v bus 5v/div . v open 50v/div . v icomp 1v/div . v gl 5v/div . v bus 5v/div . i led 500ma/div . v icomp 1v/div . v bus 5v/div . v icomp 1v/div . v ssd 100mv/div . i shor t 500ma/div . v bus 5v/div . v icomp 1v/div . v ssd 500mv/div . i led 500ma/div . v bus 5v/div . v icomp 1v/div . v cop 100mv/div . v gl 5v/div . v bus 10v/div . v comp 2v/div . v gl 5v/div . v bus 5v/div . i led 500ma/div . v icomp 1v/div . mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 13 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. pin functio n s pin # name description 1 ss soft start. this pin functio n s soft sta r t and al so set s the operatin g freque ncy togethe r with fset pin. co nne ct a re si stor (r ss_fset ) i n parallel wit h a re si stor (rss) and a capa citor (css) in se rie s to this pin. t he sou r ci ng current of this pi n togethe r wi th the sou r ci ng cu rrent of fset pin determin e s the o peratin g freq uen cy. the re sisto r r ss_fset togethe r wit h the resi sto r on fset pin sets the o p e r ating frequ en cy; the resi st or rss and t he ca pa citor css fun c tions the s o ft s t art. the norm a l voltage on this pin is 1.49 v and is pulled low to 0v at bus volta ge stage faul t con d ition. the rss and css net work sets the start up operating freque ncy an d the soft sta r t time. 2 fset freq uen cy set. conne ct a resi sto r from th is pin to gnd. th e operating freque ncy is determi ned b y the sourcin g current thro ugh this pin and ss pin. the voltage of fset pin is prog ram m ed by the current control loop an d the voltage con t rol loop, an d so do es t h e operating fre quen cy. 3 vocp over current protection of bus st age. this pin senses the sec ondary current of the bus stage, when the vocp voltage is lower than -1 00mv, ic triggers bus stage protection. 4 vfb bus voltage feedba ck. this pin fee d s b a ck the bus volta g e for regul a t ion. mp465 3 automatically sam p le s the vfb voltage at pwm o n in te r v a l an d u s es it as th e re fe r e n c e voltage of the bus voltage control loop a t pwm off interval. the voltage on vfb pin is also used for over vo ltage protection of bus voltage stage. when the voltage on vfb pin exceeds 2.4v, the over voltage protection of bus voltage stage is triggered. 5 vcomp feedb ack co mpen sation nod e of volta ge control loo p . con n e c t a comp en satio n ca pa citor o r a r-c network from this pi n to gnd. vcomp pin is also u s e d as the hiccup timer fo r the fault prote c tio n of the bus voltage stage . whe n fault condition occu rs i n the b us voltage sta g e , the vcomp is di sconn ected from t h e internal volta ge loop and t he hiccu p tim e r for the volt age bu s volta ge sta ge sta r t s . a n internal current source charges vcomp until 3v and then discharges it to 0.45v. 6 icomp feedb ack co mpen sation nod e of curre n t control loo p . conn ect a comp en satio n cap a cito r or a r-c network from this pi n to gnd. icomp pin is also used as the hiccup ti mer for the led stage prote c tio n . when fault con d ition of t he led stag e occurs, the i c omp pi n is discon ne cted from the inte rnal a m plifier and le d sta ge hi ccup tim e r starts. an internal cu rre n t sou r ce ch arge s i c om p until 3v an d then disch a rg es it to 0.45v. 7 ifb led cu rre nt feedb ack inp u t. this pin fe eds ba ck the led cu rre nt throu gh a sen s ing re si stor. the internal error am plifie r sin k s a cu rrent fr om the icomp pin p r opo rtion a l to the absol ute value of the v o ltage at thi s pin. the average volt ag e a t this pin i s regulate d to the refere nce voltage (controlled by the a-dim volt age, 0.2v when a-dim is high ). the voltage o n this pin is al so u s ed for o v er led current detectio n . when the vol t age on this pin gets hi gh er than 0.3v for 200 s o r whe n the voltage get s high er than 0.6v, the ic trigge rs the l e d stage p r ot ection. 8 ssd short string prote c tion. this pin feeds back t he se con dary sid e curre nt of the led drive r stage. when the voltage on this pin is less t han -2 00mv, ic triggers the led driver stag e prote c tion. 9 vled4 voltage feedback of led string4. 10 vled3 voltage feedback of led string3. 11 vled2 voltage feedback of led string2. mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 14 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. pin functio n s (continued) pin # name description 12 vled1 voltage feed back of led string1. vled1, vl ed2, vled3 and vled4 co rp o r ate for the prote c tion of the led driv er stag e. th e ma ximum v oltage of these pi ns a n d the voltage differen c e am ong the s e pin s are d e tecte d for led sta ge prote c tion. if the number of led strings is less than 4, connect the left pins together with others. 13 a-dim analog dimmi ng input. 0~1. 18v sets the led cu rre nt from 0 to 100%. if not use d pull it high to vcc thro u gh a 100 k ? r e si st or. 14 pwmin pwm dimming control input. apply a 100hz to 2khz pwm signal to this pin for pwm dimming 15 vin supply input. bypass this pin with a ceramic capacitor larger than 0.1 f. 16 pwmout output of the driving signal for the dimming mosfet. 17 vcc powe r suppl y for the gat e drive r an d intern al ci rcuit. bypass t h is pi n with a ce rami c capacitor larger than 1 f. 18 gl driving signal output, 180 degree phase shifted of gr 19 gnd ground reference. 20 gr driving signal output, 180 degree phase shifted of gl mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 15 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. function block diagram figure 1?MP4653 function block diagram mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 16 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. operation the mp465 3 is a cc/cv mode l l c tv led driver, espe cially desig ned for the real lips structure for the large size tv led backlight ing. powered b y 9v to 3 0 v input supplies, the MP4653 out puts two 180 degree phase shifte d driving sign als for the e x ternal power stages. it s enhanced 9v gate dr iver provides adequate driving cap ability and can direct ly drive the external mosfets through an e x ternal gate driving transformer. the mp465 3 employs frequency control for the llc po wer stage. both the le d current an d the bus voltage are controlled. figu re 1 shows the block d i agram of MP4653. internal regulator the mp46 53 include s an inte rnal linear regulator vcc. it is th e supply vo ltage for the gate driver and also for the internal circuit. the MP4653 fea t ures under voltage lockout. th e chip is d i sa bled until v cc exceed s the uvlo threshold. sy stem sta r tup when the MP4653 is powered up, the vcc i s charged up , and when it passe s the uvlo threshold, i c starts up . it resets the voltage control loo p , the cur r ent control loop and discharges t he soft start capacitor. t he MP4653 enjoys a sof t start up. the MP4653 gets a 4.35v in put uvlo threshold, a nd it can st art up directly from the system 5v standby power supply. please refer to figure 2. the pwm d i mming sign al controls t he start up of the led driver stage. the system operates in constant voltage mode and the dc bus voltage is controlled before pwm signal ap plied. cc/cv mod e operation the mp46 53 integrat es a const ant voltage control loop (cv) and a constant cur r ent control loop (cc). both the led current of the led stage and t he bus volt age of the bus voltage stage are controlled. t he pwm dimming signal is used to distinguish these two modes. at pwm on interval, the current con t rol loop is effective (cc mode) an d the led current is regulated. at pwm off interval, the voltage control loop is effe ctive and the dc bus voltage is controlled (cv mode). for the current control loop for the led current regulation, t he led current is fed back to ifb pin. the int e rnal error amplifier re gulates the average val ue of ifb signal to t he internal 200mv ref e rence voltage. its output is connected to the external current-loop compensation network on icomp pin through an inner switch s1. at pwm on interval, s1 is on, and the output of the error amplifier is connected to the external compensation network on icomp pin. the le d current is regulated by this control loop. at pwm off interval, s1 is turned off , and the co mpensation network on icomp is disconnect ed from th e error amplifier and holds its value until next pwm on interval. the output o f the error amplifier is pulled low at pwm off interval. MP4653 int egrates burst mode for the led current regulation. whe n ifb volta ge is higher than 1.1 times of its ref e rence volta ge and the icomp volt age is sufficiently low (which means a highest o perating fre quency), the ic skips some switching cycles until i f b voltage decreases sufficiently. for the voltage control loop for the bus voltage regulation, t he bus voltage is fed b a ck on vfb pin. MP4653 automatically samples the vfb voltage at p w m on inte rval and uses it as the reference f o r the volt age control loop. the internal volt age-loop er ror amplifie r regulates the average value of the vfb voltage to this reference voltage at pwm off interva l . its outpu t is con nect ed to the external voltage-loop compensation network on vcomp pin through an inner switch s2. at pwm off interval, s2 is on, and th e output of the voltag e-loop error amplifier is connect ed to th e external compensation network on vcomp pin. the b u s voltage is regulated by this contr o l loop. at pwm on in terval, s2 i s turned off, and the compensation network on vcomp i s disconnecte d from the e rror amplifier and holds its value un t il next pwm off in terval. the output mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 17 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. of the voltage-loop erro r amplifier is pulled low at pwm on interval. MP4653 also integrat es burst mode for the voltage regulation. whe n vfb volta ge is higher than 1.1 t i mes of the ref e rence volta ge and the vcomp voltage is sufficien tly low (which means a highest opera ting frequen cy), the ic skips some switching cycles until vfb voltag e decreases sufficiently. the operating frequen cy is contr o lled by th e larger one of the outputs of the current-loop error amplifier and t he voltage-loop error amplifier. a high compensation ou tput voltage gets a low o perating fre quency. dimming control the mp465 3 provides two dimming methods: pwm di mming mode and analog dimmin g mode. applying a digit a l pwm signal on the pwmin pin allows the pwm dimming. the brightness of the led string is pro portional to the duty cycle of the e x ternal pw m signal. a driving sign al on pw mout pin is output t o directly drive the dimming mosfet, which helps to achieve fast and high contrast ratio pwm dimmi ng. MP4653 achieves 500: 1 pwm dimming ratio (0.2% minimum pw m dimming dut y) at 200 hz pwm di mming frequency. the pwm dimmin g ratio may de crease with a higher pwm dimming frequency. a dc analog signal fro m 0v to 1.18v on a-dim pin dims th e led current amplitude from 0 to 100%. for pwm a nd analog dimming control, apply the pwm d i mming signal on pwmin pin and apply the analog dimming signal on a-dim pin. bus voltage stage pro t ection the mp465 3 features rich and sma r t protection to increase system reliability. it p r otects th e fault condit i on at both t he dc bus voltage stage and the led driver stage. the protection for the dc bus voltage stag e includes the over volta ge protectio n and over current prot ection (short protection). the vfb pin senses th e bus stag e voltage for voltage regulation and also for over voltage protection. when the vfb pin voltage gets higher than 2.4v for 2 u s, ic triggers the bus voltage stage protectio n . the secon dary side current of bus voltage stage is se nsed on vocp pin. when vocp voltage gets lower than -100mv, ic triggers the bus voltage stage protection. at bus voltage stage protection, the whole gate driving signals are disabled an d no power is delivered to the outpu t, includ ing both the dc bus voltage stage and the led d r iver stage. the current loop comp ensation no de icomp pin and the soft start ss pin are pu lled low. the hiccup time r for the bus voltage stage starts. the voltage-loop compensation no de vcomp pin is d i sco nnected fro m the internal amplifie r and holds its value until the fault conditio n disappears. a 2 a current source charges the vcomp pin capacitor till vcomp voltage hits 3v, and the n a 2 a current source discharges vcomp pin until 0 . 45v and then t he system recovers. led drive r stage prote c tion the fault p r otection for the led driver stage includes t h e open led protectio n , short led protection, o v er led current protection and any point of led string short to ground protection. the voltage of the led strings are sensed on vled1~vl ed4 pins. the maximum value of vled1~vl ed4 and th eir voltage d i fference ar e used for pr otection. w hen the maximu m valu e of vled1~vled4 gets h i gher than 2. 4v or their voltage diffe rence get la rger than 1 50mv (this value can be adjusted by the ext e rnal input resistance o n vled# pins), ic trigg e rs the led driver stage protection. the led cu rrent feedback ifb is also used for over led current prote c tion. when ifb voltage gets higher than 300mv for 200us or when ifb voltage gets higher than 600mv, i c triggers the led driver stage protection. the second ary side cur r ent of the led drive r stage is se nsed on s s d pin. when ssd pin voltage gets lower tha n -200mv for 2us, ic triggers the led driver stage protection. at the led driver stag e protection , the driving signal for th e dimming mosfet is disabled to mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 18 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. turn off the dimming mosfet and also to disconnect the led dri v er stage from the po we r stage. the current loop compensation nod e icomp is disconnected from the internal amplifier a nd holds its value u n til the fa ult condition on the led driver stage disappears. a 2 a current source charges the icomp pi n capacitor till icomp voltage hits 3v , and then a 2 a current source discharges icomp pin until 0.45v and then the led driver stage recovers. the gate driving signals for the mosfets in th e power stag e are cont inuous and the dc b u s voltage is regulated at t he fault con d ition of led driver stage. therefore, the system power supplies are not influenced by the fa ult protectio n of the led driver stage. thermal protection is int egrated in MP4653. 400v 5v stby vin vbus 12v/5v pwm,en led current figure 2?real lips pow e r sy ste m and start up sequence mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 19 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. start vcc pass uvlo n y pwmin= high n current loop regulation voltage loop regulation led stage fault protection led stage fault triggered n y bus stage fault trig gered n y dc bus stage fault protection y logic reset hiccup timer for led stage hiccup delay timer for bus stage monitor fault signals figure 3?sy stem ope r ation flo w chart mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 20 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. appli c ation information setting the led curren t (pin7, ifb) the external led current sensing resistor sets the maximum led current (refer to typical application circuit) and value can be determined using the equation: led 0.2 v rs e n s e i ? the iled is the total curr ent of the l e d strings. it is recommended a 1k resistor bet ween the ifb pin and the current sensing resistor for sh ort proteciton. setting the minimum/maximum operating frequenc y (pin1 ss, pi n2 fset) the operating frequ ency of MP4653 is determined by the sourcing current through ss pin and fset pin. 9 f set op ss _ f se t f s e t v 21 . 4 9 v f( ) 1 . 9 8 1 0 rr ? ?? ? ? the v fset voltage is the larger value of the outputs of in ternal amplif iers for volta ge loop and current loop. it is in rang e of 1~2.2v. the minimu m operating frequency is set by: 9 mi n ss _ f se t f se t 21 . 4 9 v 2 . 2 v f( ) 1 . 9 8 1 0 rr ? ?? ? ? the maxi mu m operating frequency is set by: 9 ma x ss _ f se t f se t 21 . 4 9 v 1 v f( ) 1 . 9 8 1 0 rr ? ?? ? ? setting the soft start u p frequency and soft start time (pin1 ss) the soft star t up frequen cy is: ss _ f se t s s 9 s_ s t a r t ss _ f se t ss f s e t 21 . 4 9 v ( r r ) 1v f( ) 1 . 9 8 1 0 r* r r ?? ? ?? ? ? usually, the soft start u p frequency could be 1. 5 to 3 times of the maximu m operating frequency. the soft st art time is determined by the rc constant of rss and c ss . the soft start t i me could be e s timated with 3 times of the rc constant: s s ss ss t3 r c ?? ? setting the voltage loop feedback (pin4 vf b) the voltage on vfb pin should b e tween 1.2v and 2v at normal op eration. set the voltag e feedback d i vider (r vfbh and r vfbl ) and make sure the fe edback volt age is in t h is range at normal operation. vfbl vf b b us vfbh vfbl r 1 . 2v v v 2v rr ?? ? ? ? the vfb pin also funct i ons as the over voltag e protection fo r the bus sta ge. when the voltage on vfb gets higher than 2. 4v, ic triggers bus stag e protection. setting ove r -voltage protection of the led stage (pin9,10,11,12) the voltage divider sets the over-volta ge protection point (refer to typical applicati o n ci rcui t) through the equation: o vph o v pl ov p ovp l rr v2 . 4 v r ? ?? normally, th e ovp point is setting about 10%- 30% higher than the maximu m led voltage. setting the voltage difference protection of the led strings (pin9,10,11,12) MP4653 implements th e protection when led string voltage is differ ent from e a ch other, in order to protect the con d ition that several leds in a str i ng ar e shorted. it is u s ed only for multiple- strings app lication. the protection point of the voltage difference between led strings is se t by: input ov ph o v p l pr o ov pl 23 k r rr v2 . 4 v r1 6 2 3 k ? ? ?? ? ? ? where r input is the input resistance of the led# pin. adjust the input r e sistance to program the protection p oint. application can add a resistor r x between the voltage divider and led# pins to a d just the inp u t resistance . ov ph o v p l in pu t x ov pl ovph rr rr rr ? ?? ? mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 21 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. setting the over current protection for the bus stage (pin3 vocp) this pin implements the over current protection for the bus stage. the current of the bus stage is sensed to this pin with a negative polarity. when the voltage on this pin is lower than -100mv, the ic triggers the bus stage protection. oc p _ bu s vocp 100 m v i r ? usually, the protection point is aro und 1.5 to 3 times of the normal current of the bu s stage. setting the over current protection for the led stage (pin8 ssd) this pin de tects the current throu gh the led stage with a negative p o larity. when the voltag e on this pin gets lower t han -200mv, ic trigge rs led stage protection. oc p _ le d ocp 200 m v i r ? the over c u rrent protection point for the led stage could usually set at around 1.5 to 2 times of the total current through the led strings. setting the voltage lo op compensation (pin5 vcomp) this pin is connected t o the output of the inn e r error amplifier for the voltage control loop through an internal switch. place a rc (r vc om p , c vcomp ) network on this pin for compensating the volta g e control loop. usually, a ceramic capa citor in rang e of 47nf t o 470nf and a resistor in range of 2k to 200k is recommend ed for the co mpensation. this pin is also used a s the hiccu p mode fault timer. whe n fault condition in th e bus stage occurs, the inner switch which connects this pin to the outpu t of error a m plifier for voltage cont rol loop turns off and a 2 a current source will charge this pin to 3v and then discharge it t o 0.45v. ic auto recovers after the hiccup timer. the hiccup delay time is: vc omp vcomp vcomp hicc u p _ v c( 3 v v ) c 2 . 5 v t 2a 2a ?? ? ?? ?? setting the current lo op compensation (pin6 icomp) this pin is connected t o the output of the inn e r error amplifier for the cu rrent control loop throug h an internal switch. place a rc (r ic om p , c ic om p ) network on this pin for the current control loop compensation. usually, a ceramic capa citor in rang e of 47nf t o 470nf and a resistor in range of 200 to 5k is recommend ed for the co mpensation. this pin is also used a s the hiccu p mode fault timer for th e led stag e. when fa ult conditio n occurs in th e led stag e, the inner switch which connects th is pin to t he output of the error amplifier for current con t rol loop tur n s off and a current source will charge this pin to 3v and then discharge it to 0.45v. the control for the led stage auto r e covers after this hiccup timer. the hiccup delay time is: i comp icomp0 icomp hiccu p _ i c( 3 v v ) c 2 . 5 v t 2a 2a ?? ? ?? ?? analog dimming (pin 13, a-dim) this pin is for analo g dimming. applying a voltage in range of 0v to 1.18v d i ms the led current from 0 to 100%. it has positive polarity f o r the analog dimming. a ceramic capacitor is recommend ed on this pin to bypass it. pwm dimm ing input (pin 14, pwmi n) this pin is for pwm dimming inpu t. applying a pwm di mming signal with frequency in range of 100hz to 2khz on this p i n. it ha s po sitive polarit y for the pwm dimming. at pwm on interval, the led current is regulated and at pwm off interval, the volta ge control loop for the dc bus funct i on s. the dc bus voltage is regulated at the value of that in pwm on interval. suppl y inp u t (pin 15, vin) this pin is the supply input voltage for the i c . bypass this pin with a 0.1uf or larger ceramic capacitor. ic starts to work when the vin volta ge is applie d. if pwmin pin is h i gh, the led current contr o l loop is effe ctive and if th e pwmin pi n is low, the voltage control loop for the dc bus control is effective. if an ?enable? signal is required t o mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 22 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. control the starting operation of the ic, use this ?enable? signal to control this supply input voltage with following circuit in figure 4. figure 4?MP4653 en able control circuit pwm dim m ing signal output (pin 16, pwmout) this pin out puts a pw m dimming signal to drive the external dimming mosfet (mn) in seri es with the led string, and achieves fast pwm dimming. connect a re sistor in ser i es with this pin to adjust the driving speed. the pwmout signal is also used t o control th e external p-mos (mp) f o r protectio n , as shown in figure 5a. figure 5b shows the operating schem e of this drivin g circuit. a n egative voltage source (- vbus) is ge nerated fro m the seco ndary winding of dc bus stage. a p u lse waveform at ?v x ? is generated through the pwmout signal. by summing the negative voltage source and v x , a pulse wave form with a negative magnitude is generated o n ?p_drive? (the p-mos gate) and is used to drive the p-mos. mp465 3 pwmout 15 . . . ifb ovp pwmout ocp vocp vfb vbus vbus pwmout r vo c p r ocp r vf b h r vf bl r ov p h r ov p l r s ens e c vb u s c o mn mp primary llc power stage -vbus p_drive pwmou t v x figure 5a?pwmout for the p_mos driver figure 5b?scheme of the pwmout driving the p_mos gate driver suppl y (pi n 17, vcc) this pin su pplies the g a te drive signals gl,gr and pwmout. bypass this pin with a 1uf or larger ceramic capacit or. this pin could also be used to sup p ly an external circu i t. gate drive signals (pin 18,20 gl,gr) gl and gr provide the driving signal for t h e power stage . gl and gr are 180 d egree phase shifted gate drive signals. with t he enhanced drive capability, gl and gr can directly drive the external mosfet in the power st age through a gate driving transformer. the gate driving transformer also isolates th e primary power stage a nd the seco ndary control circuit. place a 2.2nf y cap betwe en the power stage groun d and the r e ference gr ound for th e control cir c u i t to improve the emi performance. mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 23 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. vin pw m 400 v g n d 400v ifb ifb ovp1 pwmout pw mo ut ocp 40 0 v gnd ocp ovp1 vocp vfb vocp vfb vbus vbus pwmout a- dim ifb vc c ss fs et g n d gl pw mo ut vin gr ss d pw mi n ico m p 4 5 6 7 8 9 10 13 14 15 16 11 12 vl e d 1 vle d 2 vl e d 4 vl e d 3 17 18 19 20 vf b vco m p 2 3 vocp 1 a- d i m mp 465 3 r ss _f s e t rss css r fs e t r vcomp c vc o m p r ic om p c ico m p c in c vc c c dr v r voc p r oc p r vf b h r vf b l r ovp h 1 r ov pl 1 r se n se c v bus c o1 c r mn mp q1 q2 t1 t2 c i . . . . . . c o2 ovp2 r ov ph 2 r ov pl 2 c b r ov pi n 1 o vp2 r ovpin 2 figure 6?MP4653 ba sed led driver for 2 strings mp46 53? real lips cc/cv mode llc tv led driv e r MP4653 rev 1.0 1 www.monolithicpower.com 24 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. figure 7?MP4653 ba sed led driver for 4 strings please refer to MP4653 application note fo r the de sign pr oc ed ure and e x am ple. mp46 53? real lips cc/cv mode llc tv led driv e r notice: t he informatio n in this doc ument i s subject to ch ang e w i th out n o tice. users sh oul d w a rra nt and gu ara n tee that third part y inte llectu a l prop ert y ri gh ts are not infrin ged u p o n w h e n integr atin g mps products int o an y ap pl icati on. mps w i ll n o t assume a n y le gal res pons ib ili t y for an y sai d app licati ons. MP4653 rev 1.0 1 www.monolithicpower.com 25 6/28/2012 mps proprietar y information. pate nt protec ted. un authorized photo c op y and d uplication prohibited. ? 2012 mps. all rights reserved. package informati o n soic20 |
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