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1/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 4ch white led driver with buck-boost (40 led maximum) bd81a44muv-m / BD81A44EFV-M general description bd81a44muv-m/efv-m is a white led driver with the capability of withstanding high input voltage ( 35v max). this driver has 4ch constant-current driv ers integrated in 1-chip, where each channel can draw up to 120ma (max), which is also suitable for high illumination led drive. furthermore, a buck-boost current mode dc/dc controller is also integrat ed to achieve stable operation during power voltage fluctuation. light modulation (5000:1 dimming function) is possible by pwm input. features integrated buck-boost current mode dc/dc controller integrated 4ch current driver for led drive 5000:1 pwm dimming @200hz external switching frequency synchronization built-in protection function (uvlo, ovp, ocp, scp) led abnormality detection function (open/short) integrated v out discharge function (buck-boost or buck structure limitation) aec-q100 qualified (note 1) (note 1) grade1 application for display audio, cid, cluster, hud small and medium type lcd panels for automotive use. key specifications operating input voltage range output led current accuracy dc/dc oscillation frequency operating temperature range led maximum output current pwm min pulse width 4.5 to 35 v 3.0%@50ma 200 to 2200khz -40 to +125 120ma/ch 1.0us package(s) w(typ) x d(typ) x h(max) vqfn28sv5050 htssop-b28 (bd81a44muv-m) (BD81A44EFV-M) w(typ) d(typ) h(max) w(typ) d(typ) h(max) 5.0mm 5.0mm 1.0mm 9.7mm 6.4mm 1.0mm typical application circuit product structure silicon monolithic integrated circuit this product has no designed prot ection against radioactive rays bd81a44muv-m / BD81A44EFV-M cin vcc creg vreg vcc en vdisc ovp cs boot outh sw outl cout dgnd led1 led2 led3 led4 pgnd fail2 sync rt rrt comp rpc cpc ss css pwm iset riset gnd shdeten leden1 leden2 fail1 vreg figure 1. buck-boost application circuit datashee t downloaded from: http:///
datasheet d a t a s h e e t 2/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m pin description pin configuration vqfn28sv5050 (top view) htssop-b28 (top view) block diagram vqfn28 sv5050 htssop -b28 terminal name function 1 11 leden1 led output pin enable terminal 1 2 12 leden2 led output pin enable terminal 2 3 13 led1 led output terminal 1 4 14 led2 led output terminal 2 5 15 led3 led output terminal 3 6 16 led4 led output terminal 4 7 17 ovp over-voltage detection terminal 8 18 iset led output current setting terminal 9 19 pgnd led output gnd terminal 10 20 outl low side fet gate terminal 11 21 dgnd dc/dc output gnd terminal 12 22 vdisc output voltage discharge terminal 13 23 sw high side fet source terminal 14 24 outh high side fet gate terminal 15 25 boot high side fet driver power supply terminal 16 26 vreg internal constant voltage 17 27 en enable terminal 18 28 cs dc/dc current sense terminal 19 1 vcc input power supply terminal 20 2 ss soft start capacitor connection 21 3 comp err amp output 22 4 rt oscillation frequency-setting resistor input 23 5 sync external synchronization input terminal 24 6 shdeten short detection enable signal 25 7 gnd small signal gnd terminal 26 8 pwm pwm light modulation input terminal 27 9 fail1 failure signal output terminal 28 10 fail2 led open/short detection output signal - - thermal pad back side thermal pad (please connect to gnd) figure 3. internal block diagram figure 2. pin configuration downloaded from: http:///
datasheet d a t a s h e e t 3/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m description of blocks 1. voltage reference (v reg ) 5v (typ) is generated from the v cc input voltage (when at en=high). this voltage (v reg ) is used as power supply of internal circuit and when fixing the pins outside of the ic at a high voltage, as well. the uvlo protection is integrated in v reg . the circuit starts to operate at v cc 4.0v (typ) and v reg =3.5v (typ) and stops when at v cc 3.5v (typ) or v reg 2.0v (typ). for release/cancellation condition and detection condition, please refer to table 2 on page 11. connect a ceramic capacitor (c reg ) to vreg terminal for phase compensation. creg range is 1.0uf to 4.7uf and recommend value is 2.2uf. if the c reg is not connected, the operation of circuit will be notably unstable. 2. constant current driver table1. led control logic leden1 leden2 led1 led2 led3 led4 l l on on on on h l on on on off l h on on off off h h on off off off if less than four constant-current drivers are used, please ma ke the led1~4 terminal open while the output off by leden1 and leden2 terminal. the truth table for these pins is shown above. if the unused cons tant-current driver output will be set open without the process of leden1,2 terminals, t he open detection will be activated. the leden1, 2 terminals is pulled down internally in the ic and it is low at open co ndition. they should be connected to vreg terminal or fixed to logic high when in use. (1) output current setting (riset) figure 4. iled vs riset the output current iled can be obt ained by the following equation: [ ] = . [ ] ? riset operating range is 41kohm to 250kohm. it c an not change the riset value in the operation. this ic has iset-gnd short protection t hat protect led element from over current when iset and gnd is short. if the riset value is under 4.7kohm, the ic detects is et-gnd short and led current becomes off. 20 30 40 50 60 70 80 90 100 110 120 40 60 80 100 120 140 160 180 200 220 240 iled [ma ] riset[k ? ] iled vs riset downloaded from: http:///
datasheet d a t a s h e e t 4/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m 80 90 100 110 120 iled [ma] ta [ ] ta vs iled S vout=50mv S vout=100mv S vout=200mv if the output current i led is set to >100ma/ch, the stabilit y of led current within specifi ed operating temperature range will decrease. led current supply value will depends on the amount of ripple in output voltage (vout). the figure below shows the temperature and the possible led current maximum value settings, please adjust the ripple voltage in such a way that the led current value setting will fall within the range as shown on the graph below. ( ? vout output ripple voltage) please refer p.22, there is the detail information of vout ripple voltage. figure 5. temperature (ta) vs output led current (iled) (2) pwm intensity control figure 6. pwm=150hz, duty=0.02%, i led waveform figure 7. pwm=150hz, duty=50.0%, i led waveform the current driver on/off is controlled by pwm terminal. the duty ratio of pwm terminal becomes duty ratio of i led . if dont use pwm dimming, please set the pwm terminal to high. output light intensity is greatest at 100% input 3. buck-boost dc/dc controller (1) number of led in series connection in this ic, the output voltage of the dc/dc converter (vou t) is controlled by led cathode voltage (led1C4 terminal voltage) becomes 1.0v (typ). when two or more led are operating at the same time, the led terminal voltage that connects the highest led vf row is held at 1.0v (typ). then the voltages of other led terminal will increased only led vf tolerance. please decide led vf tolerance by using the description as shown below: led series number x led vf tolerance vo ltage < short detection voltage 4.2v (min) led control voltage 1.1v (max) (2) over voltage protection (ovp) the output of the dc/dc converter (vout) should be connect ed to the ovp pin via voltage divider. if ovp terminal voltage is over 2.0v (typ), over voltage protection (ovp) is acti ve and stop the dcdc switching. in determining an appropriate trigger voltage for ovp function, consider the total number of leds in series and the maximum variation in vf. when ovp terminal voltage drops to 1.94v (typ) after ovp operation, the ovp will be released. if rovp1 is gnd side resistance, rovp2 is output voltage side resistance and output vo ltage is vout, ovp will occur at below equation. [ ] { [ ] + [ ] / [ ] } .[] ovp will engage when v out >32v if rovp1=22k ? and rovp2=330k ? . pwm (2v/div) iled (50ma/div) pwm (2v/div) iled ( 50ma/div ) 500ns / div 1ms / div downloaded from: http:///
datasheet d a t a s h e e t 5/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m (3) buck-boost dc/dc converter oscillation frequency (fosc) figure 8. rrt vs fosc dcdc oscillation frequency can be set via a resistor connected to the rt pin. this resistor determines the charge/discharge current to the internal capa citor, thereby changing the os cillation frequency. please set the resistance of rrt using the above data and below equation. [ ] = [ ] ? where: 8110 2 is the constant value in ic (+/-10%) is the adjustment factor (rrt : = 41k ? : 1.01, 27k ? : 1.00, 18k ? : 0.99, 10 k ? : 0.98, 4.7k ? : 0.97, 3.9k ? : 0.96) a resistor in the range of 3.6 k ? to 41 k ? is recommended. settings that deviate from the frequency range shown above may cause switching to stop, and proper operation cannot be guaranteed. (4) external synchronization oscillation frequency (fsync) if the clock signal input to sync terminal, the internal oscillation frequency can be synchronized externally. do not switch from external to internal oscillation if the dc/dc converter is active. the clock input to sync terminal is valid only in rising edge. as for the external input frequency, the input of the intern al oscillation frequency 20% decided in rt terminal resistance is recommended. (5) soft start function (ss) the soft-start (ss) function can limits the start up current and output rise-time slow ly if the capacitor connected to ss terminal. it is available for prevention of output voltage overs hoot and inrush current. if you dont use soft-start function, please set ss terminal open. for the calculation of ss time, please refer to the formula on page 19. (6) max duty if this ic operates by dcdc switching max duty, it would not output expect voltage and led current decrease or led current off by scp. please set load condition and external parts for dcdc switching duty does not reach max duty. 200 2000 1 10 100 fosc [khz] rrt [kohm] rrt vs fosc downloaded from: http:///
datasheet d a t a s h e e t 6/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m 4. protect function table 2. the detect condition of each protect function and the operation during detection protect function detect condition operation during detection [detection] [release/ cancellation] uvlo v cc <3.5v or vreg<2.0v v cc >4.0v and vreg>3.5v all blocks shuts down (except for vreg) tsd tj>175c tj<150c all blocks shuts down (except for vreg) ovp vovp p >2.0v v ovp <1.94v dcdc switching off ocp v cs v cc -0.2v v cs >v cc -0.2v dcdc switching off scp one of the led1-4 is under 0.3v or vovp<0.57v (100ms delay @300khz) en reset or uvlo reset after scp delay time, all block latch off (except for vreg) led open protection vled<0.3v and vovp>2.0v en reset or uvlo reset only the detected channel latches off led short protection vled>4.5v (100ms delay @300khz) en reset or uvlo reset after led short delay time, only the detected channel latch off figure 9. protection flag output block diagram the operating status of the protection is propagated to fail1 and fail2 terminals (open-drai n outputs). fail1 becomes low when ovp or ocp protection is detected, whereas fail2 bec omes low when scp, led open or led short is detected. if the fail terminal will not be used as flag output, please make the fail terminal open or connect it to gnd. but if the fail terminal will be used as a flag output, it is recommended to pull-up the fail1, 2 terminals to vreg terminal. the recommended value of pull-up resistance is 100k . downloaded from: http:///
datasheet d a t a s h e e t 7/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m (1) under-voltage lock out (uvlo) the uvlo shuts down all the circuits except vreg wh en vcc<3.5v (typ) or vreg <2.0v (typ). and uvlo is released by vcc>4.0v(typ) and vreg>3.5v(typ). (2) thermal shut down (tsd) the tsd shuts down all the circuits except vreg when the tj reaches 175c (typ), and releases when the tj becomes below 150c (typ). (3) over-voltage protection (ovp) the output voltage of dc/dc is det ected from the ovp terminal vo ltage, and the over-voltage protection will activate if the ovp terminal voltage becomes greater than 2.0v (typ). when ovp is activa ted, the switching operation of the dc/dc turns off. and ovp terminal becomes less than 1.94v (t yp), ovp is released and t he switching operation of the dc/dc turns on. (4) over-current protection (ocp) the ocp detects the coil current by monitoring the voltage of the high-side resistor, and activates when the cs voltage becomes less than v cc -0.2v (typ). when the ocp is activated, the switching operation of t he dc/dc turns off. and cs voltage becomes over than vcc-0.2v (typ), ocp is released and the sw itching operation of the dc/dc turns on. (5) short circuit protection (scp) when the led terminal voltage becomes less than 0.3v (t yp) or ovp terminal becomes less than 0.57v (typ), the built-in counter operation will start and t he latch will activate at oscillation frequency in 32770 count. in case of fosc=300khz, the count time is approximately 100ms. if the led terminal voltage becomes over 0.3v or ovp terminal becomes over 1.0v (typ) before 32770 count, t he counter resets and scp is not detected. (6) led open detection when the led terminal voltage is below 0.3v (typ) and o vp terminal voltage more than 2.0v (typ) simultaneously, led open is detected and latches off the open channel. (7) led short detection circuit if the led terminal voltage becomes more than 4.5v (typ), the built-in counter operation will start and the latch will activate at oscillation frequency in 32770 count. in case of fosc=300khz, the count time is approximately 100ms. during pwm dimming, the led short detect operation is carri ed out only when pwm=high. if the led terminal voltage becomes less than 4.5v (typ) before 32770 count, the counter resets and led short is not detected. when led short detect function will not be used, shdeten terminal should be co nnected to vreg before starting. when led short detect function is used, the shdeten terminal should be connected to gnd. in addition, it cannot change shdeten voltage (high or low) during normal operation. (8) pwm low latch off circuit after the en is on, the low interval of pwm input is c ounted by built-in counter. the cl ock frequency of counter is the fosc frequency, which is determined by rrt, and stops the operation of circuits exc ept vreg at 32768 counts. in case of fosc=300khz, the count time is approximately 100ms. downloaded from: http:///
datasheet d a t a s h e e t 8/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m (9) output voltage discharge circuit (vdisc function) when en restart with vout charge remaining, there is the possibility of led flicker. t herefore restarting dc/dc must be operated after discharging vout. if using only pull-down resist ance as setting ovp for discharge, it takes a lot time for discharging vout. therefore this product has functionality of circuit for vout discharge. vout discharge function is available for buckboost or buck application. it is need to connect vout and vdisc terminal and use vdisc function. when vdisc terminal is connected to vout, the output can be discharged when dcdc circuit becomes off (with en changing high to low or detection of protect). the discharge time tdisc is expressed in the following equations. [ ] = [ ] [ ] [ ] where: tdisc : dc/dc output discharge time cout : dc/dc output capacity vout : dc/dc output voltage idisc : discharge current please confirm idisc value that 25% of vout voltag e from following graph and input above equation. for example, when using vout=20v, please use idisc value of vout=5v (approximately 76ma). it will take tdisc time for vout discharge. please set en=low time over than tdisc for prevent led flicker. this tdisc value is reference data. please verifying by actual measurements. figure.10 vout vs idisc 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0 5 10 15 20 25 30 35 40 idisc [a] vout [v] vout vs idisc downloaded from: http:///
datasheet d a t a s h e e t 9/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m absolute maximum ratings (ta=25c) parameter symbol rating unit power supply voltage v cc 40 v boot, outh pin voltage v boot , v outh 45 v sw, cs pin voltage v sw , v cs 40 v boot-sw pin voltage v boot-sw 7 v led1 to 4, vdisc pin voltage v led1,2,3,4 , v vdisc 40 v pwm, sync, en pin voltage v pwm, v sync, v en -0.3 to +7 v vreg, ovp, fail1, fail2, ss, rt pin voltage v vreg, v ovp, v fail1, v fail2, v ss, v rt -0.3 to +7 < vcc v leden1, leden2, iset, outl, comp, shdeten pin voltage v leden1, v leden2, v iset v outl, v comp, v shdeten -0.3 to +7 < vreg v junction temperature range tj -40 to +150 storage temperature range tstg -55 +150 led maximum output current i led 120 (note 1) ma (note 1) current level per channel. please set led current that does not over junction temperature range (tj) maximum. recommended operating ratings parameter symbol rating unit min max power supply voltage (note 2) v cc 4.5 35 v operating temp range topr -40 +125 dc/dc oscillation frequency range f osc 200 2200 khz external synchronization frequency range (note 3) (note 4) f sync 200 2200 khz external synchronization pulse duty range f sduty 40 60 % (note2) it is near vcc terminal voltage. please be careful the voltage drop by vcc line impedance. (note3) if dont use an external synchronization freque ncy, please make the sync open or connect to gnd. (note4) if using an external synchronization frequency, dont chan ge to internal oscillation in the middle of process. recommended parts ratings parameter symbol rating unit min max vreg capacitor creg 1.0 4.7 f led current setting resistance riset 41 250 k dc/dc oscillation frequency setting resistance rrt 3.6 41 k soft start setting capacitor css 0.047 0.47 f downloaded from: http:///
datasheet d a t a s h e e t 10/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m thermal resistance (note 1) parameter symbol thermal resistance (typ) unit 1s (note 3) 2s2p ( note 4) vqfn28sv5050 junction to ambient ja 128.5 31.5 c/w junction to top characterization parameter (note 2) jt 12 9 c/w htssop-b28 junction to ambient ja 107.0 25.1 c/w junction to top characterization parameter (note 2) jt 6 3 c/w (note 1) based on jesd51-2a(still-air) (note 2) the thermal characterization parameter to report the difference between junction temperature and the temperature at the top cen ter of the outside surface of the component package. (note 3) using a pcb board based on jesd51-3. layer number of measurement board material board size single fr-4 114.3mm x 76.2mm x 1.57mmt top copper pattern thickness footprints and traces 70 m (note 4) using a pcb board based on jesd51-5, 7. layer number of measurement board material board size thermal via (note 5) pitch diameter 4 layers fr-4 114.3mm x 76.2mm x 1.6mmt 1.20mm 0.30mm top 2 internal layers bottom copper pattern thickness copper patte rn thickness copper pattern thickness footprints and traces 70 m 74.2mm x 74.2mm 35 m 74.2mm x 74.2mm 70 m (note 5) this thermal via connects with th e copper pattern of all layers.. downloaded from: http:///
datasheet d a t a s h e e t 11/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m electrical characteristics (v cc =12v, ta = -40c to +125c *unless otherwise specified) parameter symbol limit unit conditions min normal max circuit current i cc - - 10 ma en=high, sync=high, rt=open pwm=low, iset=open,c in =10 f standby current i st - - 10 a en=low, vdisc=open [vreg] reference voltage v reg 4.5 5.0 5.5 v i reg =-5ma, c reg =2.2 f [outh] outh high side on-resistor r onhh 1.5 3.5 7.0 ? iouth=-10ma outh low side on-resistor r onhl 0.8 2.5 5.5 ? iouth=10ma ocp detection voltage v olimit vcc-0.22 vcc-0.2 vcc-0.18 v [outl] outl high side on-resistor r onlh 1.5 3.5 10.0 ? ioutl=-10ma outl low side on-resistor r onll 0.8 2.5 5.5 ? ioutl=10ma [sw] sw low side on-resistor r on_sw 4.0 10.0 25.0 ? isw=10ma [error amp] led control voltage v led 0.9 1.0 1.1 v comp sink current i compsink 35 80 145 a vled=2v, vcomp=1v comp source current i compsource -145 -80 -35 a vled=0.5v, vcomp=1v [oscillator] oscillation frequency 1 fosc1 285 300 315 khz rt=27k ? oscillation frequency 2 fosc2 1800 2000 2200 khz rt=3.9k ? [ovp] ovp detection voltage v ovp1 1.9 2.0 2.1 v vovp=sweep up ovp hysteresis width v ovphys1 0.02 0.06 0.10 v vovp=sweep down downloaded from: http:///
datasheet d a t a s h e e t 12/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 bd81a44muv-m/efv-m www.rohm.com tsz22111 ? 15 ? 001 electrical characteristics (v cc =12v, ta = -40c to +125c *unless otherwise specified) parameter symbol limit unit conditions min normal max [uvlo] uvlo detection voltage v uvlo 3.2 3.5 3.8 v vcc : sweep down uvlo hysteresis width v uhys 0.25 0.5 0.75 v vcc : sweep up,vreg>3.5v [led output] led current relative dispersion i led1 -3 - +3 % iled=50ma, ta=25 ? iled1=(iled/iled_avg-1)100 -5 - +5 % iled=50ma, ta=-40 125 ? iled1=(iled/iled_avg-1)100 led current absolute dispersion i led2 -3 - +3 % iled=50ma, ta=25 ? iled2=(iled/50ma-1)100 -5 - +5 % iled=50ma, ta=-40 125 ? iled2=(iled/50ma-1)100 iset voltage v iset 0.9 1.0 1.1 v riset=100k ? pwm minimum pulse width t min 1 - - s fpwm=150hz 15khz, iled=20ma 100ma pwm frequency f pwm 0.15 - 15 khz [protection circuit] led open detection voltage v open 0.2 0.3 0.4 v vled1,2,3,4= sweep down led short detection voltage v short 4.2 4.5 4.8 v vled1,2,3,4= sweep up led short detection latch off delay time t short 70 100 130 ms rrt=27k ? scp latch off delay time t scp 70 100 130 ms rrt=27k ? pwm latch off delay time t pwm 70 100 130 ms rrt=27k ? iset-gnd short protection impedance r isetprot - - 4.7 k [logic input] input high voltage v inh 2.1 - vreg v en, sync, shdeten, pwm, leden1, leden2 input low voltage v inl gnd - 0.8 v en, sync, shdeten, pwm, leden1, leden2 input current i in 15 50 100 a vin=5v(en,sync, shdeten pwm, leden1, leden2,) [fail output (open drain)] fail low voltage v ol - 0.1 0.2 v iol=0.1 a downloaded from: http:///
datasheet d a t a s h e e t 13/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 bd81a44muv-m/efv-m www.rohm.com tsz22111 ? 15 ? 001 typical performance curves 200 250 300 350 400 -40 0 40 80 120 w [] aa [] figure 12. vreg vs temperature figure 13. switching frequency vs temperature (@ 300 khz) [] a[] vcc=4.5~35v en=3.3v pwm=0v ta=25c vcc=12v en=3.3v rt=27k ? figure 11. circuit current vs supply voltage figure 14. switching frequency vs temperature (@ 2000 khz) 1000 1500 2000 2500 3000 -40 0 40 80 120 w [] aa [] vcc=12v en=3.3v rt=3.9k ? [] aa [] vcc=12v~35v en=3.3v pwm=5v downloaded from: http:///
datasheet d a t a s h e e t 14/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 bd81a44muv-m/efv-m www.rohm.com tsz22111 ? 15 ? 001 typical performance curves - continued 80 85 90 95 100 20 40 60 80 100 120 [%] [] 80 85 90 95 100 20 40 60 80 100 120 efficiency [%] output current iled1-4 [ma] [] aa [] [] a [] fi g ure 15. led current vs led volta g e figure 16. led current vs temperature figure 17. efficiency vs output current (buck-boost application) vcc=12v en=3.3v vled=2v pwm=vreg vcc=12v en=3.3v vled=sweep ta=25c figure 18. efficiency vs output current (boost application) vcc=12v en=3.3v pwm=vreg ta=25c led8series 4ch vcc=12v en=3.3v pwm=vreg ta=25c led4series 4ch downloaded from: http:///
datasheet d a t a s h e e t 15/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 bd81a44muv-m/efv-m www.rohm.com tsz22111 ? 15 ? 001 timing chart (start up and protection) figure 19. startup and protect function timing chart *1 vcc, en, pwm, sync are input sequence free. *2 the count time of 32770clk 1/f osc . in case of fosc=300khz, the count time is approximately 100ms. *3 above timing chart is the case of pulling up fail1 and fail2 terminal to vreg. 1. when vovp less than 1.0v, regardless of pwm input, the dc/dc switching operation will be active (pre-boost function). and if vovp reaches 1.0v, the pre-boost is finished. 2. when vled2 less than 0.3v and vovp more than 2.0v, led open protect is active and led2 is turned off. then fail2 becomes low. 3. if the condition of vled3 more than 4.5v passes 100m s (@fosc=300khz), led3 is turned off. then fail2 becomes low. 4. when vled4 short to gnd, increase the vout voltage. then vovp rises over 2.0v, fail1 becomes low. if ovp occur, dcdc switching is off and decrease vout voltage, then ovp repeats on/off. and dcdc switching and led current of each ch is off after approximatel y 100ms. (in case of fosc=300khz). vcc en *1 uvlo sync *1 pwm *1 ss iled1 iled2 iled3 iled4 vled1 vled2 vled3 vled4 fail1 *3 3.5v 100ms *2 vreg under 0.3v over 4.5v 2.0v under 0.3v 100ms *2 ovp 2.0v led4=gnd led3=short led2=open hi-z hi-z hi-z hi-z 1.0v fail2 *3 sw/outl/ outh 4.5v vout vovp 1.0v vf 1.94v 1.94v downloaded from: http:///
datasheet d a t a s h e e t 16/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 bd81a44muv-m/efv-m www.rohm.com tsz22111 ? 15 ? 001 timing chart (start up and restart) figure 20. start up and en restart timing chart *1 en low term when en restart needs more 2.0ms *2 please restart after vout voltage discharged. vout discharge function (p.8) or external discharge switch is available. if en restart with vout voltage remaining, there is possibility of led flash. y downloaded from: http:///
datasheet d a t a s h e e t 17/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 bd81a44muv-m/efv-m www.rohm.com tsz22111 ? 15 ? 001 application examples when using as boost dc/dc converter figure 21. boost application circuit note: when using as boost dc/dc converter, if the v out and led terminal are shorted, the over-current from vin cannot be prevented. to prevent overcurrent, carry out measure such as inserting fuse in between v cc and rcs. when using as buck dc/dc converter figure 22. buck application circuit bd81a44muv-m / BD81A44EFV-M cin vcc creg vreg vcc en vdisc ovp cs boot outh sw outl cout dgnd led1 led2 led3 led4 pgnd sync rt rrt comp rpc cpc ss css pwm iset riset gnd shdeten leden1 leden2 fail2 fail1 bd81a44muv-m / BD81A44EFV-M cin vcc creg vreg vcc en vdisc ovp cs boot outh sw outl cout dgnd led1 led2 led3 led4 pgnd sync rt rrt comp rpc cpc ss css pwm iset riset gnd shdeten leden1 leden2 fail2 fail1 downloaded from: http:///
datasheet d a t a s h e e t 18/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 bd81a44muv-m/efv-m www.rohm.com tsz22111 ? 15 ? 001 pcb application circuit figure 23. pcb application circuit ? please arrange rrt resistor closest to rt pin and do not attach capacitor. ? please arrange riset resistor closest to iset pin and do not attach capacitor. ? please attach the decoupling capacitor of cin and creg to ic pin as close as possible. ? because there is possibility that big current may flow into dgnd and pgnd, please make the impedance low. ? in pins of iset, rt and comp, please pay attention so that noise will not get in. ? since pwm, outh, outl, sw, sync and led 1-4 are switchin g, please pay attention so that it will not affect the surrounding pattern. ? there is a heat dissipation pad at the back of package. please solder the board for the heat dissipation pad. ? please set the gate resistor of step-down fet (m1) to 0 ? . if resistor is connected, m1 off timing is delayed in m1 parasitic capacity and gate resistor, and the penetrating current flows to the internal transistor of m1 and sw. ocp may be detected by penetrating current. ? to reduce noise, please consider the board lay out in the shortest min impedance for boost loop (d2 cout dgnd m2 d2) and buck loop (vcc rcs m1 d1 dgnd gnd cin vcc). ? the ringing of low side fet is decreased by rg1, but if rg1 value is increased, there is c oncern about a decrease of efficiency. please evaluate to determine the proper value of rg1 to be used. . downloaded from: http:///
datasheet d a t a s h e e t 19/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m pcb board external components list buck boost application serial no. component name component value product name manufacturer 1 cin1 10 f gcm32ec71h106ka01 murata 2 cin2 3 cin3 4 rcs1 100m ? mcr100 sieries rohm 5 rcs2 100m ? mcr100 sieries rohm 6 rcs3 short 7 ccs 8 css 0.1 f gcm15r71h104ke37 murata 9 cpc1 0.01 f gcm15r71h104ke37 murata 10 rpc1 5.1k ? mcr03 series rohm 11 rrt1 27k ? mcr03 series rohm 12 rfl1 100k ? mcr03 series rohm 13 rfl2 100k ? mcr03 series rohm 14 creg 2.2 f gcm188c71a225ke01 murata 15 cboot 0.1 f gcm155r71h104ke37 murata 16 rboot short 17 l1 22 h slf12565t-220m3r5-pf tdk 18 m1 rss070n05 rohm 19 m2 rss070n05 rohm 20 d1 rb050l-40 rohm 21 d2 rb050l-40 rohm 22 cout1 10 f gcm32ec71h106ka01 murata 23 cout2 10 f gcm32ec71h106ka01 murata 24 cout3 10 f gcm32ec71h106ka01 murata 25 cout4 10 f gcm32ec71h106ka01 murata 26 rovp1 30k ? mcr03 series rohm 27 rovp2 360k ? mcr03 series rohm 28 riset1 100k ? mcr03 series rohm 29 rg1 0 ? * above components should be changed by load or conditions. downloaded from: http:///
datasheet d a t a s h e e t 20/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m selection of components externally connected follow the steps as shown below for selecting the external components. 1. computation of input p eak current il_max from application condition 2. set the rcs value so that it becomes iocp>il_max 3. select the value of l so that it becomes 0.05v/ s < ? rcs<0.63xfosc [mhz] please judge the l value. if its ok, go to 4. and if its ng, go back to 1. 4. select the coil, schottky diode, mo sfet and rcs which meets the current and voltage ratings. 5. select the output capacitor which meets with the ripple voltage requirements. 6. select the input capacitor. 8. phase characteristics adjustment (cpc, rpc) 9. over-voltage protection setting (rovp1, rovp2). 10. soft start time selection (css). 11. check the startup time v out l l value is feed back 7. select the boot ? sw capacitor. 12. en restart check 13. actual operation confirmation a aa downloaded from: http:///
datasheet d a t a s h e e t 21/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m 1. input peak current il_max computation internal ic cs outh sw cout outl vin rcs m1 d2 l vout d1 il m2 figure 24. output application circuit diagr am (in case of buck-boost application) (1) max output voltage (vout_max) computation consider the vf variation and number of led connection in series for vout_max derivation _ = +? + . vout_max [v] : max output voltage vf[v] : led vf voltage ? vf[v] : led vf voltage variation n : led series number (2) max output current i out_max computation _ = . iout_max[a] : max input peak current iled[a] : output current per channel m : led parallel number (3) max input peak current i l_max computation _ = _ + M ? il_max[a] : max input peak current il_avg[a] : max input average current il[a] : input current amplification (in case of boost application) _ = _ _ M ? = _ _ (in case of buck-boost application) _ = + _ _ M ? = _ _ (in case of buck application) _ = _ M ? = _ vcc[v] input voltage ? efficiency fosc[hz] switching frequency l[h] coil value the worst case for vin is minimum, so the minimum value should be applied in the equation. the current-mode type of dc/dc convertor is adopted for bd81a34muv-m/efv-m, which is optimized with the use of the recommended l value in the design stage. this recommendation is based upon the efficiency as well as the stability. the l values outside this recommended range may cause irregular sw itching waveform and hence deteriorate stable operation. n (efficiency) becomes almost 80%. 2. setting of over-current protection (iocp) value [ ] = _[]= . [] > _[] rcs should be selected by above equation. downloaded from: http:///
datasheet d a t a s h e e t 22/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m 3. selection of the inductor in order to achieve stable operation of t he current mode dc/dc converter, we recomm end selecting the l value in the range indicated below. .[ ? ]< [ ] [ ] [ ] < . [] since there is almost 30% variation in the value of coil l, keep enough margin and set. the smaller [ ] [ ] [ ] allows stability improvement but slows down the response time. if the condition of vcc is under 5v, please sa tisfy below equation when selecting the coil. [] < [ ] [ ] [ ] [][] the coil outside of above equations may cause low led brightness. 4. selection of coil l, diode d1 , d2, mosfet m1, rcs and cout current rating voltage rating heat loss coil l > i l_max D D diode d1 > iocp > vcc_max D diode d2 > iocp > vovp_max D mosfet m1 > iocp > vcc_max D mosfet m2 > iocp > vovp_max D r cs D D > iocp 2 rcs c out D >vovp_max D please consider external parts deviation and make the setting with enough margin. in order to achieve fast switching, choose th e mosfets with the smaller gate-capacitance. 5. selection of output capacitor select the output capacitor cout based on t he requirement of the ripple voltage voutpp. [] = [ ] [ ] [ ] +? [] [] actually, vout ripple voltage is sensitive to pcb layout and external components c haracteristics. therefore, when designing for mass-production, stability should be th oroughly investigated and conf irmed in the actual physical design. available cout max value is 500uf. 6. selection of input capacitor we recommend an input capacitor greater than 10 f with the small esr ceramic capacitor. the input capacitor outside of our recommendation may cause large ripple voltage at the input and hence le ad to malfunction. 7. selection of boot C sw capacitor when using the buckboost application or buck applicat ion, please input boot - sw capacitor 0.1uf. downloaded from: http:///
datasheet d a t a s h e e t 23/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m 8. phase characteristics adjustment figure 25. comp terminal application circuit diagram about application stability condition the stability in led voltage feedback system is achieved when the following conditions are met. (1) the phase delay when gain is 1(0db) is below 150c (or simply, phase margin >30c). (2) the frequency (unity gain frequency) when gain is 1(0db) is <1/10 of switching frequency. one way to assure stability based on phase margin adjustment is setting the phase-lead fz close to switching frequency. in addition, the phase-lag fp1 shall be deci ded based on cout and output impedance rl. respective formula shall be as follows. phase-lead [] = [] [ ] phase-lag [] = [ ] [] (note) the output impedance calculated from = good stability would be obtained when the fz is set between 1khz 10khz. it is important to keep in mind that these are very loose gu idelines, and adjustments may have to be made to ensure stability in the actual circuitry. it is also impor tant to note that stability characterist ics can change greatly depending on factors su ch as substrate layout and load conditions . therefore, when designing for mass-pro duction, stability should be thoroughly investigated and confirmed in the actual physical design. 9. setting of over voltage protection(ovp) over voltage protection (ovp) is set from the external resistance rovp1 and rovp2. the setting described below will be important in the either boost, buck, buck-boost applications. figure 26. ovp application circuit the ovp terminal detects the over voltage when at >2.0v (typ) and stops the dc/dc switching. in addition, it detects the open condition when ovp terminal is at >2.0v (typ) and led1 to 4 pin voltage is at <0.3v (typ), and the circuit is latched to off (please refer to page 11, protect function). in preventing erro r in detection of open, it is necessary that the resistor divide voltage of the maximum value of output voltage shall be less than the min value of open detection voltage. please set the rovp1 and rovp2 is such a way the formula shown below can be met. [] { [ ] [ ] + [ ] ? } < [] (1) vout : dc/dc output voltage vo vpopen : ovp pin open detection voltage vout led1~4 a internal ic comp rpc cpc rovp2 rovp1 ovp vout internal ic 2.0v/1.94v 1.0v/0.57v downloaded from: http:///
datasheet d a t a s h e e t 24/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m sample 1: when v f =3.2v0.3v led is used in 8series [] = . + . + . = . open detection ovp pin voltage =. if rovp1=20k ? , please set by rovp2 > 286.3k ? from (1) sample 2: vf=3.2v0.3v led is used in 3series [] = . + . + . = . open detection ovp pin voltage =. if rovp1=20k ? , please set by rovp2 > 102.21k ? from (1). 10. setting of soft start time the soft start circuit minimizes the coil cu rrent at the input and oversh oot at the output voltage during the start-up conditio n. a capacitance in the range of 0. 047 to 0.47f is recommended. a capacitance of less than 0.047f may cause overshoot at the output voltage. however, a capacitanc e greater than 0.47f may cause massive reverse current through the parasitic elements when power supply is off and may damage the ic. soft start time tss (typ) is below. [ ] = [] .[] M [] css: the capacitance at ss terminal 11. check the start up time if the pwm duty at start up is sm all, the start up time is longer. if you want to setup the startup time shorter, small cpc val ue is available, but it needs phase margin check. below data is pwm duty vs startup time of representative two conditions. condition 1 (boost, below figure left side) vcc = 12v, vout = 30v (assumed led 8 series), rrt = 27k ? (fosc = 300khz), cpc=0.01 f, rpc=5.1k ? , css = 0.1 f, rovp1 = 20k ? , rovp2 = 360k ? figure 27. pwm duty vs startup time (boost) condition 2 (buckboost, below figure right side) vcc = 12v, vout = 20v (assumed led 5 series), rrt = 27k ? (fosc = 300khz), cpc=0.01 f, rpc=5.1k ? , css = 0.1 f, rovp1 = 30k ? , rovp2 = 360k ? figure 28. pwm duty vs startup time (buckboost) above data is only reference dat a. actual startup time depe nds on layout pattern, parts value and part characteristics, please verify your design by the actual measurements. 0 100 200 300 400 500 600 700 800 900 1000 0 2 04 06 08 01 0 0 start up time [ms] pwm duty [%] pwm duty vs startup time (boost) 0 100 200 300 400 500 600 700 800 900 1000 0 0.2 0.4 0.6 0.8 1 start up time [ms] pwm duty [%] pwm duty vs startup time (boost, zoom up) 0 100 200 300 400 500 600 700 800 900 1000 0 2 04 06 08 01 0 0 start up time [ms] pwm duty [%] pwm duty vs startup time (buckboost) 0 100 200 300 400 500 600 700 800 900 1000 00 . 20 . 40 . 60 . 81 start up time [ms] pwm duty [%] pwm duty vs startup time (buckboost, zoom up) downloaded from: http:///
datasheet d a t a s h e e t 25/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m 12. en restart check en restart when vout voltage is remain, it possible to dete ct scp. please set the condition according to applications. when use the buckboost or buck application. please connect vout and vdisc terminal and set en=low time refer to the below equation. [ ] = [ ] [ ] [ ] < [] regarding tdisc details, please refer p.8. when use the boost application. please adjust css and cpc value according to below. if cpc value is changed, phase margin will changed, and if css value is changed, start up time is changed. pl ease verifying by actual measurements. [ ] = .+.? [ ] . + . [ ] [ ] + . []/ . [%] [ ] = [ ] . + ./[] please adjust css and cpc value with [ ] <[] n : ledseries number vcc[v] : power supply fosc[khz] : dcdc frequency rrt[k ] : rt resistence cpc[ f] : comp capacitor duty[%] : pwm duty css[ f] : ss capacitor ex.) n=7, vcc=7v, fosc=300khz, rrt=27k , cpc=0.01 f, c s s = 0 . 1 f, pwm duty = 1% [ ] = . + . ? .+. + . ./ . =. [ ] = . . + . = . [ ] <[] this condition is ok. 13. verification of the operation by taking measurements the overall characteristics may change based on load current, input voltage, output voltage, inductance, load capacitance, switching frequency, and pcb layout. we strongly recomm end verifying your design by the actual measurements. downloaded from: http:///
datasheet d a t a s h e e t 26/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m additional parts for emc 1. this part adjusts slew rate of high side fet. 2. this part decreases noise of current loop of high side fet. 3. this part decreases spectrum of high frequency on power line. 4. this low pass filter decreases noise of power line. 5. this common mode filter de creases noise of power line. 6. this snubber circuit decreases spectr um of high frequency of low side fet. 7. this snubber circuit decreases ringing of switching for low side fet. bd81a44muv-m / BD81A44EFV-M cin creg vreg vcc en vdisc ovp cs boot outh sw outl cout dgnd led1 led2 led3 led4 pgnd sync rt rrt comp rpc cpc ss css pwm iset riset gnd shdeten leden1 leden2 vcc fail2 fail1 figure 29. application parts for emc downloaded from: http:///
datasheet d a t a s h e e t 27/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m attention point for pcb layout the layout pattern influences characteristic, such as efficiency and a ripple greatly. so, it is necessary to examine carefully about it. boost dc/dc has loop1 (in the right side figure). placement of these parts should be compact. and wiring should be low-impedance (e.g. couts gnd and dgnd should be very near). also, back-boost dc/dc has loop2. placement of these parts and wiring should be compact and low-impedance (e.g. cins gnd and d1s gnd should be very near). figure 30. circuit of dc/dc block rcs d1 d2 cin cout m1 figure 31. BD81A44EFV-M pcb top-laye r m2 bd81a44muv/efv-m cs outh sw vcc rcs m1 cout vout cin outl l d2 m2 d1 downloaded from: http:///
datasheet d a t a s h e e t 28/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m calculation of power consumption = ??? circuit power + ??? boost fet power + ??? buck fet power +{ + ? ? } ??? current driver power pc[w] : ic power consumption icc[a] : max ci rcuit current vcc [v] : power supply voltage ciss1[f] : boost fet gate capacitance ciss2[f] : b uck fet gate capacity vreg[v] : vreg voltage fsw[hz] : switching frequency vled[v] : led control voltage iled [a] : led output current m : number of led parallel vf[v] : led vf torelance icc=10ma, vcc=12v, ciss1=2000pf, ciss2=2000pf, vreg=5v, fsw=2200khz, vled=1v, iled=50ma, n=7, m=4 vf=3.5v, ? vf=0.5v, n=80% = . + . + = = . = . _ = + ? . . ? = . = + + + { . + . ? } = .[] the above mentioned is a simple calculation and someti mes the value may differ from the actual value. downloaded from: http:///
datasheet d a t a s h e e t 29/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m i/o equivalence circuit all values are typ value. ss comp rt vcc 1k ss vreg 10k vreg vreg comp 1k vreg 5k rt 1k 12.5 ? sync,pwm pwm sync 100k 10k vreg fail1,fail2 shdeten,leden1,leden2 shdeten leden1 leden2 vreg 100k 10k vreg fail1 fail2 1k led1~4 ovp iset led1 led2 led3 led4 10k vreg 100k 2 ? 90k ovp 10k 10k 10k 10k 10k iset 1k vreg 1k outl vdisc sw outl vreg vdisc sw vcc outh boot vreg outh boot boot sw 1k boot sw boot vreg vreg vcc en cs en 62.5k 125k 1.1k 2p cs vcc 166 ? 5k vcc vreg sw sw downloaded from: http:///
datasheet d a t a s h e e t 30/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m operational notes 1. reverse connection of power supply connecting the power supply in reverse polarity can damage the ic. take precautions against reverse polarity when connecting the power supply, such as mounting an ex ternal diode between the power supply and the ics power supply pins. 2. power supply lines design the pcb layout pattern to provide low impedance supply lines. furthermore, connect a capacitor to ground at all power supply pins. consider the effect of temperature and aging on the c apacitance value when using electrolytic capacitors. 3. ground voltage ensure that no pins are at a voltage below that of t he ground pin at any time, even during transient condition. 4. ground wiring pattern when using both small-signal and large-current ground trac es, the two ground traces s hould be routed separately but connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal ground caused by large currents. also ensure that the ground traces of external components do not cause variations on the ground voltage. the ground lines must be as s hort and thick as possible to reduce line impedance. 5. thermal consideration should by any chance the power dissipation rating be exceeded the rise in temperature of the chip may result in deterioration of the properties of the chip. in case of exceeding this abs olute maximum rating, increase the board size and copper area to prevent exceeding the pd rating. 6. recommended operating conditions these conditions represent a range within which the expect ed characteristics of the ic can be approximately obtained. the electrical characteristics are guaranteed under the conditions of each parameter. 7. inrush current when power is first supplied to the ic, it is possible that the internal logic may be unstable and inrush current may flow instantaneously due to the internal powering sequence and delays, especially if the ic has more than one power supply. therefore, give special consi deration to power coupling capacitance, po wer wiring, width of ground wiring, and routing of connections. 8. operation under strong electromagnetic field operating the ic in the presence of a strong electromagnetic field may cause the ic to malfunction. 9. testing on application boards when testing the ic on an application board, connecting a capacitor directly to a low-impedance output pin may subject the ic to stress. always discharge capacitors completely after each process or step. the ics power supply should always be turned off completely before connecting or removing it from the test setup during the inspection process. to prevent damage from static discharge, ground the ic during assembly and use similar precautions during transport and storage. 10. inter-pin short and mounting errors ensure that the direction and position are correct when mountin g the ic on the pcb. incorre ct mounting may result in damaging the ic. avoid nearby pins being shorted to each ot her especially to ground, power supply and output pin. inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment) and unintentional solder bridge deposited in between pins during assembly to name a few. 11. unused input pins input pins of an ic are often connec ted to the gate of a mos transistor. the gate has extremely high impedance and extremely low capacitance. if left unconnect ed, the electric field from the outsi de can easily charge it. the small charge acquired in this way is enough to produce a sign ificant effect on the conduction through the transistor and cause unexpected operation of the ic. so unless otherwise specified, unused input pins should be connected to the power supply or ground line. downloaded from: http:///
datasheet d a t a s h e e t 31/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m operational notes C continued 12. regarding the input pin of the ic this monolithic ic contains p+ isolat ion and p substrate layers between adjac ent elements in order to keep them isolated. p-n junctions are formed at the intersection of the p layers with the n layers of other elements, creating a parasitic diode or transistor. for example (refer to figure below): when gnd > pin a and gnd > pin b, the p-n junction operates as a parasitic diode. when gnd > pin b, the p-n junction o perates as a parasitic transistor. parasitic diodes inevitably occur in the structure of the ic. the oper ation of parasitic diodes can result in mutual interference among circuits, operational faults, or physical damage. therefore, conditions that cause these diodes to operate, such as applying a voltage lowe r than the gnd voltage to an input pin (and thus to the p substrate) should be avoided. figure 32. example of monolithic ic structure 13. ceramic capacitor when using a ceramic capacitor, determine the dielectric constant considering the change of capacitance with temperature and the decrease in nominal capacitance due to dc bias and others. 14. area of safe operation (aso) operate the ic such that t he output voltage, output current, and power di ssipation are all within the area of safe operation (aso). 15. thermal shutdown circuit(tsd) this ic has a built-in thermal shutdown circuit that prevents heat damage to t he ic. normal operation should always be within the ics power dissipation rating. if however t he rating is exceeded for a continued period, the junction temperature (tj) will rise which will activate the tsd circui t that will turn off all output pins. when the tj falls below the tsd threshold, the circuits are autom atically restored to normal operation. note that the tsd circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no circumstances, should the tsd circuit be used in a set design or for any purpose other t han protecting the ic from heat damage. 16. over current protection circuit (ocp) this ic incorporates an integrated over current protection circuit that is acti vated when the load is shorted. this protection circuit is effective in pr eventing damage due to sudden and unexpect ed incidents. however, the ic should not be used in applications characterized by continuous operation or transit ioning of the protection circuit. downloaded from: http:///
datasheet d a t a s h e e t 32/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m ordering information bd81a44muv - m e 2 package muv:vqfn28sv5050 packing & foaming specification m: high reliability design e2: reel shape embossed taping (vqfn28sv5050) bd81a44efv - m e 2 package efv:htssop-b28 packing & foaming specification m: high reliability design e2: reel shape embossed taping (htssop-b28) marking diagram part number marking package orderable part number bd81a44muv vqfn28sv5050 bd81a44muv-me2 bd81a44efv htssop-b28 BD81A44EFV-Me2 vqfn28sv5050 (top view) bd81a 44muv part number marking lot numbe r 1pin mark htssop-b28 (top view) bd81a44efv part number marking lot numbe r 1pin mark downloaded from: http:///
datasheet d a t a s h e e t 33/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m physical dimension tape and reel information (bd81a44muv-m) package name vqfn28sv5050 downloaded from: http:///
datasheet d a t a s h e e t 34/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m physical dimension, tape and reel information (BD81A44EFV-M) package name htssop-b28 ? order quantity needs to be multiple of the minimum quantity. embossed carrier tape (with dry pack) tapequantity direction of feed the direction is the 1pin of product is at the upper left when you hold reel on the left hand and you pull out the tape on the right hand 2500pcs e2 () direction of feed reel 1pin downloaded from: http:///
datasheet d a t a s h e e t 35/35 tsz02201-0t3t0c600060-1-2 ? 2016 rohm co., ltd. all rights reserved. 2016.4.26rev.002 www.rohm.com tsz22111 ? 15 ? 001 bd81a44muv-m/efv-m revision history date revision changes 2016/1/13 001 new 2016/4/26 002 p. 9 absolute maximum ratings pwm, sync and en terminal. before : -0.3 to +7 < vcc after : -0.3 to +7 p.10 thermal resistance 2 internal layers / copper pa ttern, bottom / copper pattern before : 74.2mm 2 (square) after : 74.2mm x 74.2mm p.29 i/o equivalence circuit change rt, outl, outh and en terminal. downloaded from: http:///
notice-paa-e rev.003 ? 201 5 rohm co., ltd. all rights reserved. notice precaution on using rohm products 1. if you intend to use our products in devices requiring extreme ly high reliability (such as medical equipment (note 1) , aircraft/spacecraft, nuclear power controllers, etc.) and whose malfunction or failure may cause loss of human life , bodily injury or serious damage to property ( specific applications ), please consult with the rohm sales representative in advance. unless otherwise agreed in writin g by rohm in advance, rohm shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any rohm s products for specific applications. (note1) medical equipment classification of the specific applic ations japan usa eu china class class class b class class ? class 2. rohm designs and manufactures its products subject to stri ct quality control system. however, semiconductor products can fail or malfunction at a certain rate. please be sure to implement, at your own responsibilities, adeq uate safety measures including but not limited to fail-safe desig n against the physical injury, damage to any property, whic h a failure or malfunction of our products may cause. the followi ng are examples of safety measures: [a] installation of protection circuits or other protective devic es to improve system safety [b] installation of redundant circuits to reduce the impact of single or multiple circuit failure 3. our products are no t designed under any special or extraordinary environments or conditions, as exemplified below . accordingly, rohm shall not be in any way responsible or liable for any damages, expenses or losses arising from the use of any rohms products under any special or extraordinary environments or conditions. if you intend to use our products under any special or extraordinary environments or c onditions (as exemplified below), your independent verification and confirmation of product performance, reliabil ity, etc, prior to use, must be necessary: [a] use of our products in any types of liquid, including water, oils, chemicals, and organi c solvents [b] use of our products outdoors or in places where the products are exposed to direct sunlight or dust [c] use of our products in places where the products are e xposed to sea wind or corrosive gases, including cl 2 , h 2 s, nh 3 , so 2 , and no 2 [d] use of our products in places where the products are exposed t o static electricity or electromagnetic waves [e] use of our products in proximity to heat-producing component s, plastic cords, or other flammable items [f] sealing or coating our products with resin or other coating materials [g] use of our products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of flux is recommended); or washing our products by using water or water-soluble cleaning agents for cleaning residue after soldering [h] use of the products in places subject to dew condensation 4. the products are not subject to radiation-proof design. 5. please verify and confirm characteristics of the final or mou nted products in using the products. 6 . in particular, if a transient load (a large amount of load appl ied in a short period of time, such as pulse. is applied, confirmation of performance characteristics after on-board mou nting is strongly recommended. avoid applying power exceeding normal rated power; exceeding the power rating u nder steady-state loading condition may negatively affec t product performance and reliability. 7. de -rate power dissipation depending on ambient temperature. wh en used in sealed area, confirm that it is the use in the range that does not exceed the maximum junction temperature. 8 . confirm that operation temperature is within the specified range desc ribed in the product specification. 9 . rohm shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in this document. precaution for mounting / circuit board design 1. when a highly active halogenous (chlorine, bromine, etc .) flux is used, the residue of flux may negatively affect prod uct performance and reliability. 2. in principle, the reflow soldering method must be used on a surface-mount products, the flow soldering method mus t be used on a through hole mount products. i f the flow soldering method is preferred on a surface-mount p roducts, please consult with th e rohm representative in advance. for details, please refer to rohm mounting specification downloaded from: http:///
notice-paa-e rev.003 ? 201 5 rohm co., ltd. all rights reserved. precautions regarding application examples and external circuits 1. if change is made to the constant of an external circuit, p lease allow a sufficient margin considering variations o f the characteristics of the products and external components, inc luding transient characteristics, as well as static characteristics. 2. you agree that application notes, reference designs, and a ssociated data and information contain ed in this document are presented only as guidance for products use. therefore, i n case you use such information, you are solely responsible for it and you must exercise your own independ ent verification and judgment in the use of such information contained in this document. rohm shall not be in any way respon sible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of such informat ion. precaution for electrostatic this product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. please take p roper caution in your manufacturing process and storage so t hat voltage exceeding the products maximum rating will not be applied to products. please take special care under dry co ndition (e.g. grounding of human body / equipment / solder iro n, isolation from charged objects, setting of ionizer, friction prevention and temperature / humidity control). precaution for storage / transportation 1. product performance and soldered connections may deteriorate if the products are stored in the places where: [a] the products are exposed to sea winds or corrosive gases, in cluding cl2, h2s, nh3, so2, and no2 [b] the temperature or humidity exceeds those recommended by rohm [c] the products are exposed to direct sunshine or condensation [d] the products are exposed to high electrostatic 2. even under rohm recommended storage condition, solderabil ity of products out of recommended storage time period may be degraded. it is strongly recommended to confirm so lderability before using products of which storage time is exceeding the recommended storage time period. 3. store / transport cartons in the correct direction, which is indi cated on a carton with a symbol. otherwise bent leads may occur due to excessive stress applied when dropping of a carton. 4. use products within the specified time after opening a humi dity barrier bag. baking is required before using products of which storage time is exceeding the recommended storage tim e period. precaution for product label a two-dimensional barcode printed on rohm products label is f or rohm s internal use only. precaution for disposition when disposing products please dispose them properly usi ng an authorized industry waste company. precaution for foreign exchange and foreign trade act since concerned goods might be fallen under listed items of export control prescribed by foreign exchange and foreign trade act, please consult with rohm in case of export. precaution regarding intellectual property rights 1. all information and data including but not limited to appl ication example contained in this document is for reference only. rohm does not warrant that foregoing information or data will not infringe any intellectual property rights or any other rights of any third party regarding such information or data. 2. rohm shall not have any obligations where the claims, a ctions or demands arising from the combination of the products with other articles such as components, circuits, systems or ex ternal equipment (including software). 3. no license, expressly or implied, is granted hereby under any inte llectual property rights or other rights of rohm or any third parties with respect to the products or the information contai ned in this document. provided, however, that rohm will not assert its intellectual property rights or other rights a gainst you or your customers to the extent necessary to manufacture or sell products containing the products, subject to th e terms and conditions herein. other precaution 1. this document may not be reprinted or reproduced, in whole or in p art, without prior written consent of rohm. 2. the products may not be disassembled, converted, modified , reproduced or otherwise changed without prior written consent of rohm. 3. in no event shall you use in any way whatsoever the pr oducts and the related technical information contained in the products or this document for any military purposes, includi ng but not limited to, the development of mass-destruction weapons. 4. the proper names of companies or products described in this document are trademarks or registered trademarks of rohm, its affiliated companies or third parties. downloaded from: http:///
datasheet datasheet notice ? we rev.001 ? 2015 rohm co., ltd. all rights reserved. general precaution 1. before you use our pro ducts, you are requested to care fully read this document and fully understand its contents. rohm shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny rohms products against warning, caution or note contained in this document. 2. all information contained in this docume nt is current as of the issuing date and subj ec t to change without any prior notice. before purchasing or using rohms products, please confirm the la test information with a rohm sale s representative. 3. the information contained in this doc ument is provi ded on an as is basis and rohm does not warrant that all information contained in this document is accurate an d/or error-free. rohm shall not be in an y way responsible or liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or concerning such information. downloaded from: http:///

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