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product structure silicon monolithic integrated circuit ? this product is not designed prot ection against radioactive rays 1/36 www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 14k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 datashee t 4-channel white led driver with integrated fet for up to 40 leds BD65D00MUV ? general description this ic is white led driver ic with pwm step-up dc/dc converter that can boost max 41v and current driver that can drive max 100ma. the wide and precision brightness can be controlled by external pwm pulse. this ic has very accurate current drivers, and it has few current errors between each strings. so, it will be helpful to reduce brightness spots on the lcd panel. small package is suited for saving space. it can respond to the application according to the application to be abele to switch to external/internal nchfet boosting. ? features ? high efficiency pwm step-up dc/dc converter (fsw=typ 1.25mhz, 0.60mhz to 1.6mhz) ? high accuracy & good matching current drivers 4ch (max100ma/ch) ? integrated 50v power nch mosfet ? soft start function ? drive up to 10 leds in series, 4 strings in parallel ? various safety functions over-voltage protection external sbd open detect / output short protection over current limit ch terminal open / gnd short protect ch over voltage protect / led short protect thermal shutdown uvlo iset short protection ? pwm dimming(100hz - 25khz)analog brightness control ? key specifications ? operating power supply voltage range: 6v to 27v ? led maximum current: 100ma/ch ? quiescent current: 1.6 a (typ.) ? operating temperature range: -40 ? to +85 ? ? package ? ? ? ? ? ? w(typ.) x d(typ.) x h(max.) ? a pplications all lcd equipments, backlight of notebook pc, amusement, net book, monitor, tv, portable dvd player, light source etc. ? typical application circuit (4 parallel) figure 2. typical application circuit 6v to 27v v qfn028 v 5050 5.00mm x 5.00mm x 1.00mm figure 1.
2/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? absolute maximum ratings (ta=25 ?) parameter symbol ratings unit conditions terminal voltage 1 vmax1 7 v vdc, iset, abc, comp, fset, test, fault, preout, trin, sensp terminal voltage 2 vmax2 45 v ch1 to ch4, lx, ovp terminal voltage 3 vmax3 30.5 v vin, enable terminal voltage 4 vmax4 15 v pwm power dissipation 1 pd1 380 *1 mw power dissipation 2 pd2 880 *2 mw power dissipation 3 pd3 3264 *3 mw operating temperature range topr -40 to +85 ? storage temperature range tstg -55 to +150 ? *1 reduced 3.0mw/ ? with ta>25 ? when not mounted on a heat radiation board. *2 1 layer (rohm standard board) has been mounted. copper foil area 0mm 2 , when it?s used by more than ta=25 ? , it?s reduced by 7.0mw/ ?. *3 4 layer (jedec compliant board) has been m ounted. copper foil area 1.4layer 20.2mm 2 , copper foil area 2 to 3layers 5505mm 2 , when it?s used by more than ta=25 ? , it?s reduced by 26.1mw/ ?. ? power dissipation is calculated by formula : (storage temperature max - 25 ? )/ ja (ex. pd1=3.0mw/ ?) ? recommended operating ratings (ta=-40 ?to +85 ?) parameter symbol limits unit conditions min. typ. max. power supply voltage vinl 6.0 12.0 27.0 v coil power supply vin 4.5 5 27.0 v ic power supply ? electrical characteristics (unless otherwise specified, vin=12v, ta = +25 ?) parameter symbol limits unit conditions min. typ. max. [general] quiescent current iq - 1.6 4.4 a enable=0v current consumption idd - 3.6 5.4 ma ovp=0v,iset=39k ? max. output voltage mov - - 41 v under voltage lock out uvlo - 3.7 4.1 v vin falling edge [enable terminal] low level input voltage enl 0.0 - 0.8 v high level input voltage 1 enh 2.0 - vin v enable pull down resistor enr 100 300 500 k ? enable =3v output current eniout - 0 2 a enable=0v [pwm terminal] low level input voltage pwml 0.0 - 0.8 v high level input voltage 2 pwmh 1.3 - 14.5 v pwm pull down resistor pwmr 100 300 500 k ? pwm=3v output current pwmiout - 0 2 a pwm=0v [fault] nch ron ffcr - - 3 k ? enable=pwm=3v, ovp=2v [regulator] vdc voltage vreg 4.2 5.0 6.0 v no load, vin > 6v 3/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? electrical characteristics - continued (unless otherwise specified, vin=12v, ta = +25 ?) parameter symbol limits unit conditions min. typ. max. [switching regulator] led control voltage vled 0.64 0.80 0.96 v switching frequency accuracy fs w 1.00 1.25 1.50 mhz fset=56k ? duty cycle limit duty 91.0 95.0 99.0 % ch1-4=0.3v, fset=56k ? lx nch fet ron ron - 0.3 0.5 ? ilx=80ma [protection] over current limit ocp 1.5 2.5 - a *1 over voltage limit input ovp 1.16 1.20 1.24 v detect voltage of ovp pin output short protect ovpfault 0.02 0.05 0.08 v detect voltage of ovp pin ovp leak current ovil - 0.1 1.0 a ch terminal over voltage protect accuracy vsc -15 0 +15 % vsc=8v [current driver] led maximum current ilmax - - 100 ma this is current driver?s characteristics. this ic may not output current according to application. led current accuracy ilaccu - - 5.0 % iled=60ma (39k ? ) led current matching ilmat - - 3.0 % (max led current ? min led current)/ ideal current (60ma) iled=60ma led current limiter ilocp - 0 0.1 ma current limit value at iset resistance 1k ? setting iset voltage iset - 0.733 - v led current accuracy2 ilaccu2 - 3.0 - % iled=60ma, abc=0.733v *1 this parameter is tested with dc measurement. ? block diagram pin number 22pin figure 3. block diagram currentsense sense 4/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? pin descriptions pin no. pin name io function terminal diagram 1 vdc out regulator output / internal power-supply c 2 test in test signal (pull down 100k ? within ic) e 3 fset in resistor connection for frequency setting a 4 abc in pin for analog brightness control c 5 gnd - gnd for switching regulator b 6 comp out erramp output a 7 iset in resistor connection for led current setting a 8 ch4 in current driver sink for ch4 c 9 nc - - - 10 ch3 in current driver sink for ch3 c 11 nc - - - 12 ch2 in current driver sink for ch2 c 13 nc - - - 14 ch1 in current driver sink for ch1 c 15 nc - - - 16 gnd - gnd for current driver b 17 fault out fault signal c 18 preout out signal output pin for internal switching tr a 19 trin in gate termi nal for switching tr a 20 sensp in source terminal for external switching tr a 21 pgnd - pgnd for switching tr d 22 lx out switching tr drive terminal f 23 lx 24 nc - - - 25 ovp in detect input for sbd open and ovp c 26 pwm in input pin for current driver power on/off e 27 enable in pin for power on/off or power control e 28 vin in battery input g - thermal pad - heat radiation pad of back side connect to gnd ? pin esd type figure 4. pin esd type vdc 5/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? typical performance curves figure 8. under voltage lock out figure 5. quiescent current figure 6. current consumption figure 7. vdc voltage 6/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? typical performance curves figure 9. fault ron figure 10. switching frequency figure 11. max duty figure 12. lx nch ron fre q uenc y ( mhz ) 7/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? typical performance curves - continued figure 14. over voltage protect figure 16. ovp leak current figure 13. over current limit figure 15. output short protect 8/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? typical performance curves - continued figure 18. led current vs. ch voltage figure 19. iset voltage figure 17. ch terminal ovp figure 20. led current matching 9/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? typical performance curves - continued figure 21. led open time vs. temp figure 22. led short time vs. temp figure 23. thermal shut down figure 24. efficiency 10ledx4ch iled=60ma 10/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? typical performance curves - continued figure 25. led current vs. pwm duty pwm freq=200hz fset=56k ? figure 26. led current vs. pwm duty pwm freq=30khz fset=56k ? 11/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? application example figure 27, figure 28 and figure 29 are application examples. recommended schematics and layout are shown in page 29, 31. figure 27. bd65d00 application example (4 parallel) figure 28. bd65d00 application example (3 parallel) BD65D00MUV ch1 ch 2 ch 3 ch 4 ov p 10 serial x 4 parallel (40pcs) 60ma abc lx lx 2.2f/50v fa u lt vin 10h 10f iset 39k ? gnd pgnd vdc pgnd 2.2m ? 68k ? vout 2.2f gnd pgnd fset test 56k ? 1nf 12v to 27v(vinl) e nable p wm 2.1v to vin c omp 1k ? pwm f pw m =1 00 hz~2 5khz 22nf reset preout trin sensp 10 ? BD65D00MUV ch1 ch 2 ch 3 ov p 10 serial x 3 parallel (30pcs) 60ma abc lx lx 2.2f/50v fa u lt vin 10h 10f iset 39k ? gnd pgnd vdc pgnd 2.2m ? 68k ? vout 2.2f gnd pgnd fset test 56k ? 1nf 9v to 27v(vinl) e nable p wm 2.1v to vin c omp 1k ? pwm f pw m =1 00 hz~2 5khz 22nf reset preout trin sensp 10 ? ch 4 12/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 figure 29. bd65d00 application example (2 parallel) BD65D00MUV ch1 ch 2 ov p 10 serial x 2 parallel (40pcs) 60ma abc lx lx 2.2f/50v fa u lt vin 10h 10f iset 39k ? gnd pgnd vdc pgnd 2.2m ? 68k ? vout 2.2f gnd pgnd fset test 56k ? 1nf 6v to 27v(vinl) e nable p wm 2.1v to vin c omp 1k ? pwm f pw m =1 00 hz~2 5khz 22nf reset preout trin sensp 10 ? ch 3 ch 4 13/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? functional descriptions 1) pwm current mode dc/dc converter this detects the lowest voltage inside ch 1,2,3,4 pin voltage during power on. pwm duty is decided to be 0.8v and output voltage is kept invariably. as for the input soft the pwm co mparator as the feature of the pwm current mode, one is overlapped with error components from the error amplifier, and the other is overlapped with a current sense signal that controls the inductor current into slope waveform to prevent s ub harmonic oscillation. this output controls internal nch tr via the rs latch. in the period where inte rnal nch tr gate is on, energy is accumulated in the external inductor, and in the period where internal nch tr gate is off, energy is transferred to the output capacitor via external sbd. this ic has many safety functions, and their det ection signals stop switching operation at once. 2) pulse skip control this ic regulates the output voltage using an improved pulse-skip. in ?pulse-ski p? mode the error amplifier disables ?switching? of the power stages when it detects low outpu t voltage and high input voltage. the oscillator halts and the controller skip switching cycles. the error amplifier reactivate s the oscillator and starts swit ching of the power stages again when this ic detects low input voltage. at light loads a conventional ?pulse-skip? regulation mode is used. the ?pulse- skip? regulation minimizes the operating current because this ic does not switch continuously and hence the losses of t he switching are reduced. when the error amplifier disables ?switching?, the load is al so isolated from the input. this improved ?pulse-skip? control is also referred t o as active-cycle control. figure 30. pulse-skip 3) soft start this ic has soft start function. the soft start function prevents large coil current. rush current at turning on is prevented by the soft start function. the soft start of this ic controls over-current setting hence peak is controlled. therefore, before switching phenomenon (not pulse-skip phenomenon) occurs, soft start (the phenomenon wher e-in current flows to the coil) will not start (stop). pulse-skip can release soft-start if the switching on/off time is set. after changing enable pin, pwm pin from ?l? ? ?h?, regulator (vdc) voltage increases. soft start is effective within the period 4.3ms when uvlo is detect ed and when it exceeds vdc=3.9v (typ.). once soft start is finished, even if you change pwm from ?l? ? ?h?, soft start does not work. figure 31. soft start pwm vout led current lx 60ma duty 20% @1.25mhz(typ) pulse skip pwm v out lx led current en able v dc s oft start pw m pulse-skip max 1ms typ 4.3ms off on off on uvlo on off enabl max 1m s off on off on vdc soft star t pwm uvlo off t1 t2 soft start tim e=t 1+t 2=4.3m s typ. 14/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 4) fault when the error condition occurs, boost oper ating is stopped by the protection functi on avoiding error condition. ?l? is outputted from fault pin when an error occurs. after power-on, unt il soft start is released, ar ound 4.3ms (typ.), protection functions do not operate (except tsd). when enable pin is changed to ?l?, even if output of faul t pin latches, it will still reset to the initial status. (in pulse-skip state, while the switching is stopped, the mask time of the fault pin becomes longer since the soft start is also stopped.) when using 3 parallel connection of led in le ss than 4.3ms (typ.), the fault pin will output ?l? if the process of the unused pin is not yet finish ed. evaluate sufficiently the start up time when the connected capacitor between comp pin & gnd starts up smoothly. object of protect function is as shown below. - over-voltage protection (ovp) - thermal shut down (otp) - over current protect (ocp) - output short protect - led short (latch) - led open (latch) figure 32. fault operating description fault protect function (ovp, ocp) boost operation enable vdc pwm protect function (led open, led short) protect function (tsd) off normal boost stop normal off normal undetected detected undetected typ4.3 ms ?x? ?x? ?l? ?l? ?h? ?l? ?h? mask undetected detected undetected latch t y p100s undetected detected undetected ?l? ?h? ?l? ?h? ?h? ?l? 15/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? protection protection table case failure mode detection mode ch1 pin ch2 to 4 pin vout adjustment fault terminal 1 led short ( led ch1 is short) ch1 > vsc led current stop and dc/dc feedback doesn?t return normal burning dc/dc feedbacks at ch2 to ch4 adjust vf of led at ch2 to ch4 at the biggest line ?h? ? ?l? (latch) 2 led open ( led ch1 is open) ch1 < 0.2v(typ.) and ovp > 1.2v(typ.) led current stop and dc/dc feedback doesn?t return normal burning dc/dc feedbacks at ch2 to ch4 adjust vf of led at ch2 to ch4 at the biggest line ?h? ? ?l? (latch) 3 vout/lx gnd short ovp < 50mv(typ.) fault change from ?h? to ?l?, and switching is stopped. when ovp>50mv, fault return ?h? - ?h? ? ?l? 4 output led stack voltage too high ovp > 1.2v(typ.) fault change from ?h? to ?l ?, and switching is stopped. ovp<1.2v, fault returns to ?h ? (does not return when it occurs at the same time with led open) - ?h? ? ?l? 5 lx current too high ocp > 2.5a or otp > 175 c(typ.) fault change from ?h ? to ?l ?, and switching is stopped. fault pin does not returns to ?h ? because ic shutdowns and when enable is from ?h ? to l until ?h ?. - ?h? ? ?l? ? over voltage protection (ovp) when led is separated it will result to output open and over step-up. when the built-in (external) tr and ovp pin exceed the absolute maximum rating, the built-in (external) tr and ic will break down. thus, ovp pin when more than the detect voltage will turn into over voltage protection st atus turning off switching and stopping dc/dc. after over voltage protection, as shown in figure 33, the ic changes from activation into non-activation, and the output voltage goes down slowly. and when the feedback of ch1 isn?t returned, feedback takes place in ch2. figure 33. ovp operating description vout ch1 volta g e ch1 connection ch2 connection feedbac k enabl e , pwm normal ch1 ch1 ch2 normal ope n ch1 curren t 60ma 0m a ch2 curren t 60ma 0m a ovp signal hysteresis(typ 2.5%) 16/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 the value shown in electrical characteristics is used here. over voltage limit min 1.16v typ 1.20v max 1.24v led control voltage min 0.64v typ 0.80v max 0.96v led terminal over voltage protect min 6.80v typ 8.00 v max 9.20v 1. calculate the condition of the total value of led vf. example) in the case of serial 8 leds with vf=2 .9v (min), 3.2v (typ.), 3.5v (max) => 3.5v x 8=28v 2. then calculate the biggest value of output with the following formula. the biggest value of output = the biggest value calculated in #1 + the biggest value of led terminal voltage. (0.96v) example) the biggest value of output = 28v + 0.96v =28.96v 3. set the smallest value of over voltage larger than the biggest value of output. if over voltage is closer to the total value of vf, it could be occurred to detect over voltage by ripple, noise, and so on. it is recommended that some margins should be left on the difference between over voltage and the total value of vf. this time around 6% margin is placed. example) output largest value = 28.96v, the smallest value of over vo ltage = 28.96v x 1.06 = 30.70v ic over voltage limit min=1.16v, typ=1.20v, max=1.24v typ = 30.70v(1.20v/1.16v) = 31.76v max = 31.76v(1.26v/1.20v) = 33.35v 4. below shows how to adjust setting resistor value. please fix resistor high between ovp terminal and output and then set over voltage after changing resistor between ovp terminal and gnd. if this resistor value is decreased, output voltage will also decrease while pwm is turned off, hence ripple of output voltage becomes larger and the sound/noise of output capacitor also increases. example) selecting ovp resistor (r1 and r2). ? ovp resistor selection (example. 1) vf=3.5v max, serial = 7 led ovp = 1.2v, r1 = 2.2m ? , r2 = 95.3k ? vout = 1.2 (2.2m ? + 95.3k ? )/ 95.3k? = 28.90v (example. 2) vf=3.5v max, serial = 8 led ovp = 1.2v, r1 = 2.2m ? , r2 = 82k ? vout = 1.2 (2.2m ? + 82k ? )/ 82k ? = 33.40v (example. 3) vf=3.5v max, serial = 9 led ovp = 1.2v, r1 = 2.2m ? , r2 = 73.2k ? vout = 1.2 (2.2m ? + 73.2k ? )/ 73.2k? = 37.27v (example. 4) vf=3.5v max, serial = 10 led ovp = 1.2v, r1 = 2.2m ? , r2 = 68k ? vout = 1.2 (2.2m ? + 68k ? )/ 68k ? = 40.02v ?;,9405(3 vout r1 r2 17/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? over current protection over current flows in current detect resi stor that is connected between internal switching tr source and pgnd. when it increases beyond detect voltage, over cu rrent protect operates. over current protec t prevents it becoming more than detect voltage by reducing on duty of switchi ng tr without stopping boosting operation. since the over current detector of this ic detects peak current, more than setting value of over current doesn?t flow. if both pwm=h (boosting condition) and over current situation keep going during continuous 2ms, the ic shuts down. by making enable ?h?->?l?->?h?, the ic activates again. the ic might shut down if boosting operation starts with slow speed of power supply activation and also low voltage. please operate after setting input voltage that is required for application. ? external sbd open detect / output short protection if in case external sbd and dc/dc output (v out) connection is open, or vout is short ed in gnd, there is a risk that coil and the internal tr might break down. therefore, at such an error as ovp becoming 50mv (typ.) or below, turns off the output tr, and prevents the coil and the ic from being destructed. and the ic changes from activation into non-acti vation, current does not flow to the coil (0ma). ? thermal shut down this ic has thermal shut down function. the thermal shut down works at 175 c (typ.) or higher, and the ic changes from activation into non-activation. 2ms fault coil current over current protec t ch1 terminal enabl e oc p pw m internal reset continuous 2ms(typ.) fault termina l 0 v latch reset 18/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? operating of the a pplication deficiency 1) when 1 led or 1string open during the operation the led string which became open isn't lighting (e.g. ch1), but other led strings are lighting. as shown in figure 34, when the strings in ch1 are open, ch1 pin become 0v. the lowest voltage is below 0.8v thus the output will boost up to over voltage protection voltage. when ov er voltage protect is detect ed, open process starts. once open, since the pin which is the obj ect of the feedback is excluded, vout returns to normal voltage. 2)when led short-circuited in multiple all led strings are lighted unless ch1 to 4 terminal voltage is more than 8v(typ.). when it was more than 8v only t he strings which short-circuited are turned off, le d current strings of other lines continue to turn on normally. short line (ch1) current is changed from 60ma to 0.05ma (typ.), so ch1 terminal don?t heat. ? 3)when schottky diode remove ic breakdown is prevented by stopping boost operation thru schottky diode protection function (ovp pin <50mv). ch 1 ch 2 ch 1 ch 2 figure 34. led open protect figure 35. led short protect vout ch1 voltage ch1 connection ch2 connection feedback enable, pw ch1 curren t normal ch1 off ch 2 normal o p en 60ma 0ma ch2 curren t 60ma 0m a ch1 ovp ch1 enable 100 s ch1terminal feedback ch1 current ch1 ch2 ch2 current 60ma 60ma 0.05ma(typ.) vout 0.8v led short ? ch2 terminal 0.8v typ 8v ch1>ch2 100 s(typ.) 19/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? control signal input timing timing sequence1 figure 36. shows the power on sequence. enable and pwm signal from ?l? to ?h? after charging current (vin on). power off sequence, on the other hand, is turn ing off power supply (vin) after enable and pwm signal turns from h to l. timing sequence2 figure 37. shows the power on sequence. power supply charge (vin on), enable signals from l to h, then pwm signal from l to h. power off sequence, on t he other hand, is turning off power s upply (vin)and enable, pwm signal from h to l. enable, pwm vin power on power off led ic timing sequence for pwm control turn-on vin 2 ~ 5v min 0 s pw m enable min 0 s 6.0 ~ 27v 1.3~5v 0 ~ 0.8v 0 ~ 0.8v 0v led ic timing sequence for pwm control turn-off pw m 2 ~ 5v min 0 s vin enabl e min 0 s 6.0 ~ 27v 2 ~ 5v 0 ~ 0.8v 0 ~ 0.8v 0v figure 36. timing sequence1 pwm vin, enable power on power off en able 2 ~ 5v min 0 s vin pw m min 0 s 6.0 ~ 27v 1.3~5v 0 ~ 0.8v 0 ~ 0.8v 0v vin 2 ~ 5v min 0 s en able pw m min 0 s 6.0 ~ 27v 1.3~5v 0 ~ 0.8v 0 ~ 0.8v 0v led ic timing sequence for pwm control turn-on figure 37. timing sequence2 led ic timing sequence for pwm control turn-off *other signals are inputted after signals are turned on. *other signals are inputted after signals are turned off. *other signals are inputted after signals are turned on. *other signals are inputted after signals are turned off. 20/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 timing sequence3 figure 38.shows power on sequence. power supply charge (vin on), pwm from l to h, then afterwards enable signal from l to h. power off sequence is power supply (vin) off, pwm signal from h to l then enable signal from h to l. vin wake up speed figure 39. control signal timing in case there is pwm off status (min: 10ms) during operation, enable is reset (?h? to ?l?) as shown in figure 40. if pwm stops and vout voltage is dropped, this ic will be in current limiter state when pwm starts (no soft start). if soft start is not necessary, ther e is no need also to reset. vin min. 100s 6.0 v 1 2 figure 40. pwm stop and enable turn ?off? pwm off vin enable min 10ms pwm pwm reset enable vin, pwm power on power off pw m 2 ~ 5 v min 0 s vin en abl e min 0 s 6.0 ~ 27v 1.3~5 v 0 ~ 0.8v 0 ~ 0.8v 0v vin 2 ~ 5v min 0 s pw m enable min 0 s 4.2 ~ 27v 2 ~ 5v 0 ~ 0.8v 0 ~ 0.8v 0v led ic timing sequence for pwm control turn-on figure 38. timing sequence3 led ic timing sequence for pwm control tn *other signals are inputted after signals are turned on. *other signals are inputted after signals are turned off. 21/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? how to activate pay attention to the following when activating. ? regulator (vdc) is operated after enable=h. inner circuit is operated after releasing uvlo. when boosting after releasing uvlo, soft start function is operated. soft start circuit needs t 15 (more than 5s) such as figure 41. soft start is operated during tsoft time. set pwm width ?h? until soft start finishes. example: time until soft start finishes at pwm frequency 25khz and pwm=h time is 6s by soft start time typ 4.3ms tsoft = 6s - 5s = 1s soft start time / tsoft / pwm frequency = 4300s / 1s / 25khz = 172ms at dimming with pwm terminal (after soft start finishes) figure 41. soft start figure 42. timing input (after soft start) "$ ? vin vdc enable t1 h[v] t2 t3 t14 t6 t10 t11 t7 t9 t8 t4 t5 h[v] pwm t14 t3 vin terminal vdc terminal enable terminal uvlo si g nal pwm terminal soft start up to ocp value (0a to 2.5a ) t t soft comp terminal pulse-skip signal t detect skip lx terminal stop to switching name unit min. typ. max. t1 power supply rise time s 100 - - t2 power supply - enable rise time s0 - - t3 enable rise time s 0 - 100 t4 enable fall time s 0 - 100 t5 enable low width s50 - - t6 power supply - pwm time s0 - - t7 pwm rise time s 0 - 100 t8 pwm high width s5 - - t9 pwm fall time s 0 - 100 t10 pwm low width s5 - - t11 pwm cycle s 40 5000 10000 t12 enable(h)->pwm(h) time s0 - - t13 enable(l)->pwm(l) time s0 - - t14 pwm(l)->enable(l) time s0 - - t15 soft start set up time s5 - - h operation voltage v 4.2 12 27 l no operation voltage v - - 4.2 22/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? how to select the number of led strings of the current driver in order to reduce the number of strings of current driver, open unnecessary ch1 to 4 pins for them not to be selected. when using 2 strings, open the unnecessary 2 strings. during vout wake up in an open state, vout boost up until ovp voltage. once ic detect ovp, vout don?t boost up until ovp from next start up. if enable set to ?l,? ic resets ch4 status as shown figure 43. also during vout wake up, ch4 (open terminal) and ch1 are selected as shown figure 44. ? figure 43. select the number of ch1 strings figure 44. select the number of ch4 strings (wake up) ch 1 ch 2 ch 3 vout ch1~3 ch4 ovp normal volta g e 0.8v ( t yp . ) 0v 0v pwm enabl e reset mask open ch1 curren t ch4 termina l ch4 curren t 60m a vou t soft start: typ 4.3ms enabl e sta b le pw m ch1 termina l 0m a 0m a feedback terminal typ 0.8v over voltage protect signal ?unmask te rm i na l s e le c t ( led open prot ec t ) ch1 ch4 normal condition over voltage protect 100 s(typ.) 23/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? start control (enable) and led current driver selection (pwm) this ic can control the ic system by enable, and ic can power off compulsory by setting 0.8v or below. also, it powers on enable is at more than 2.0v. after it?s selected to enable=h, when it is selected at pwm=h, led current decided with iset resistance flow. next, when it is selected at pw m=l, led current stop to flow. enable pwm ic led current 0 0 off off 1 0 on off 0 1 off off 1 1 on current decided with iset ? led current setting range normal current setting is done thru resist or (riset) connected to voltage of iset. setting of each led current is given as shown below. riset = 2340/iledmax also, normal current setting range is 30ma to 100ma. led cu rrent becomes a leak curren t max 2a at off setting. iset normal current setting example riset led current 24k ? (e24) 97.5ma 30k ? (e24) 78.0ma 39k ? (e24) 60.0ma 43k ? (e24) 54.4ma 68k ? (e24) 34.4ma ? frequency setting range switching frequency can be set by connecting the resistor to fset pin. also, frequency setting range is 0.60mhz to 1.60mhz. the below diagrams are the reference data that shows what happens when fset terminal is connected to resister. fset frequency setting example rfset frequency 130k ? (e96) 0.57mhz 56k ? (e24) 1.25mhz 43k ? (e24) 1.59mhz max duty example frequency max duty[%] min typ max 600mhz - 96.0 - 1.25mhz 91.0 95.0 99.0 1.6mhz - 92.0 - min duty example frequency min duty[%] min typ max 1.25mhz - 20 - frequency [mhz] 1.25 56k ? 130 k ? fset[k ? ] 0.57 1.59 43 k ? 24/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? pwm dimming current driver pwm control is controlled by providi ng pwm signal to pwm port, as it is shown figure 45. the current set up with iset is chosen as the h section of pwm and the current is off as the l section. therefore, the average led current is increasing in proportion to duty cycle of pwm signal. this method that it lets internal circuit and dc/dc to work, because it becomes to sw itch the driver, the current toleranc e is a few when the pwm brightness is adjusted, it makes it possible to brightne ss control until 5s (min 0.1% at 200hz). a nd, don't use for the brightness control, because effect of iset changeover is big under 1s on time and under 1s off time. typical pwm frequency is 100hz to 25khz. ? analog dimming this ic controls led current thru an analog input (abc terminal). led current is determined thru the resistor connected to iset. normal state is abc voltage= typ 0.733v. decrease led current to decrease abc voltage and increase led current to increase abc voltage. in order to get the max value of led current, follow the setting range of led current found in page 18. be careful that the setting led current max value is abc voltage=0.733v (typ.). abc input range is 0.05v ? 0.9v. this dimming is effected by iset tolerance. when analog dimming is not used, connect capacitor to abc terminal. led current increases until charging of the capacitor at the abc terminal is finished. the resistor between 1.2v and abc terminal is 120.9k ? . take into consideration the charge time before deciding the capacitor value. pwm led current coil current ic?s active current on off on off on off on figure 45. pwm sequence iset + - iset resistor driver abc 1.2v 0.733v dc input 120.9k ? 39k ? 180k ? iset + - iset resistor driver abc 1.2v 0.733v 120.9k ? 180k ? 39k ? figure 46. analog dimming application figure 47. pwm dimming application figure 48. iled vs. abc voltage iled [ma] 60ma 0.733 v 0.9v abc[v] 73.7ma riset=39k ? 25/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ?coil selection the dc/dc is designed by more than 4.7h. when ?l? value sets to a lower value, it is possibility that the specific sub-harmonic oscillation of current mode dc / dc will be happened. do not let ?l? value to 3.3h or below. when ?l? value increases, the phase margin of dc / dc becom es zero. please enlarge the output capacitor value when you increase ?l? value. make the resistor component smaller in order to increase the efficiency of dcr inductor. please estimate peak current of coil as shown in the examples below. peak current calculation 26/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? output capacitor selection output capacitor smoothly keeps output voltage and supplies le d current. output voltage consists of charge (fet on) and discharge (led current). so output voltage has ou tput ripple voltage in every fet switching. output ripple voltage is calculated as following. output ripple voltage - switching cycle = t - total led current = i led - switching on duty = d - output ripple voltage = v ripple - output capacitor = c out - output capacitor (real value) = c real - decreasing ratio of capacitor = c error c real = c out c error (capacitor value is decreased by bias, so) c real = i led (1-d) t / v ripple c out = i led (1-d) t / v ripple / c error (example 1) in case of, v in =12.0v, fsw = 1.2mhz, vout =32v, i led =120ma, c out = 8.8f, c error = 50% t = 1 / 1.2mhz d = 1 ? v in / vout = 1 ? 12/32 v ripple ? ?= i led (1-d) t / (c out c error ) = 120ma (12/32) / 1.2mhz / (8.8f0.5) = ? 8.5mv 0v 35v 50v output voltage capa [ f] c out c real figure 49. bias characteristics of capacitor 27/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? the separations of the ic power supply and coil power supply this ic can work in separating the power source in both ic power supply and coil power supply. with this application, it can decrease ic power consumption, and can correspond to applied voltage exceeds ic rating 27v. that application is shown in below figure 50. the higher volt age source is applied to the power source of coil that is connected from an adapter etc. next, the ic power supply is connected with a different coil power supply. under the conditions for inputting from 4.5v to 5.5v into ic vin, please follow the recommend design in figure 50. it connects vin terminal and vdc terminal together at ic outside. when the coil power supply is applied, there is no any problem even though ic power supply is the state of 0v. although ic power supply is set to 0v, pull-down resistance is arranged for the power off which cuts off the leak route from coil power supply in ic inside, the leak route is cut off. and, ther e is no power on-off sequence of coil power supply and ic power supply. however, there?s an instance where the over current protection may be affected if t he power supply was inputted last in the coil because the enable and pwm were inputted already and also because of under voltage t hat was detected before the power supply stabilizes. before it reaches the needed voltage in the applications to be used, turn off the enable and pwm input. separate vin and coil power supply connect vin and vdc terminals figure 50. application at the ti me of power supply isolation BD65D00MUV ch 1 ch 2 ch 3 ch 4 ov p 10 serial x 4 parallel (40pcs) 60ma abc lx lx 2.2f/50v fa u lt vin 10h 10f iset 39k ? gnd pgnd vdc pgnd 2.2m ? 68k ? vo ut 2.2f gnd pg nd fset test 56k ? 1nf 12v to 27v (vinl) e nable p wm 2.1v to vin c omp 1k ? pwm f pw m =100hz~25khz 22nf reset preo ut trin sensp 10 ? BD65D00MUV ch 1 ch 2 ch 3 ch 4 ov p 10 serial x 4 parallel (40pcs) 60ma abc lx lx 2.2f/50v fa u lt vin 10h 10f iset 39k ? gnd pgnd vdc pgnd 2.2m ? 68k ? vo ut 2.2f gnd pg nd fset test 56k ? 1nf 6v to 32v(vinl) e nable p wm 2.1v to vin c omp 1k ? pwm f pw m =100hz~25khz 22nf reset preo ut trin sensp 10 ? 4.5 to 5.5v 28/36 BD65D00MUV datasheet www.rohm.com ? 2012 rohm co., ltd. all rights reserved. tsz22111 k 15k 001 tsz02201-0g3g0c400220-1-2 7.dec.2012 rev.001 ? pcb layout in order to make the most of the performance of this ic, its pc b layout is very important. characteristics such as efficiency and ripple and the likes change greatly with lay out patterns, which please note carefully. figure 51. schematic |