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AP2152 ms1348-e-00 1 2012/05 description the AP2152 is a 3 channel white led driver ic. it i s composed of a current mode dc/dc boost converter with an internal power mosfet and 3 channe l constant current sources, which can drive up to 10 leds per channel for a maximum of 30 leds. the AP2152 achieves 0.8% typ. led current matching between each channel when the led current is set at 75.8ma. the led current can be run up to a maximum of 120ma with the appropriate external set resistor on the iset pin. the AP2152 operates over a wide input voltage range f rom 4.25v to 35v, and the switching frequency goes up to a maximum of 2.5mhz with the appr opriate external set resistor on the rt pin. the switching frequency can also be synchronized wi th an external signal. the AP2152 provides the led dimming function via an external pwm signal, with a frequency range from 100hz to 20khz. the AP2152 provides led open protection, led short prot ection, ovp pin short protection, channel short protection, over voltage protection, over curre nt protection, thermal protection and uvlo. features white led driving number: maximum 30 pieces (10 pie ces in series x 3 in parallel) led current matching: 0.8% typ. (i led =75.8ma) led maximum current: 120ma maximum switching frequency: 2.5mhz pwm dimming frequency by applying external signal: maximum 20khz input voltage range: 4.25v 35v built-in 45v power mosfet error flag through serial interface synchronize with external frequency master C slave configuration led open protection led short protection ovp pin short protection output channel short protection overvoltage protection (ovp) over current protection thermal protection uvlo 20 pin htssop with heat-sink package applications display backlight lighting equipment AP2152 3ch high power wled driver
AP2152 ms1348-e-00 2 2012/05 block diagram uvlo os c sw itch logic timer la tch ldo 5.0v 17 ch3 18 ch2 19 ch1 ovp vin vdc tm rt iset gnd 20 10 14 8 9 low side current s ink 13 cs ch1 ch2 ch3 ove r voltage p rotecti on error amp dimmi ng cont rol thermal shutdown 5 12 pwm comparator pwm 11 comp pwm cs current sense cs vdc voltage select le d timer 3 ch short 4 3 sclk sdata lx pgnd 1 2 dri ver ? + reg 3.0v vout short prot ection led s hort protecti on 3 vosp timer ch open protecti on 3 4bit seria l i/f 3 timer latch vdc ss current sink pwm error amp s s 6 7 sync clko 15 pgood fail ch vosp tsd vosp tsd vout cout vin figure 1. AP2152 block diagram rovp1 rovp2
AP2152 ms1348-e-00 3 2012/05 pin layout and application circuit example top view 1 7 ch3 1 8 ch2 1 9 ch1 ovp vin vdc tm rt iset gn d 2 0 10 1 4 8 9 5 12 pwm 11 comp 4 3 sclk sdata lx pgn d 1 2 6 4 sync clko 1 5 pgood c in2 c out2 l d c out 1 c in1 r ovp2- 1 vout r iset r t r sy nc c vdc c t m c c omp 2 pwm input r ovp1 13 vin r ovp2- 2 c com p 1 r comp figure 2. AP2152 pin layout and a circuit example pin description pin no. pin name function 1 lx power mosfet pin. nch mosfet open-drain. if 2.6a or higher current is detected on this pin, over-current protection circuit is activated. 2 pgnd gnd for power mosfet 3 sdata data output from serial interface. nch open-drain o utput. the output data will be synchronized with the clock input on the sclk pin.. when the data function is unnecessary please connect to gnd. 4 sclk clock input for serial interface. when the clock fu nction is unnecessary please connect to gnd. 5 pwm pwm dimming signal input pin. built-in 200k pull down resistor. this also functions as the enable input, and if this pin goes to a high le vel, the ic is changed from the stand-by state to the enable state, the internal ldo is acti vated, and the boost operation begins. if this pin goes to a low level, the internal timer st arts counting, 30msec later the ic goes into the standby state. 6 sync clock input pin for synchronous operation. built-in 1m pull-down resistor. if the synchronous operation is unnecessary, please connect to gnd. 7 clko internal clock output pin. if the clock func tion is unnecessary, please keep this pin open. 8 vin power input pin. internal ldo input to provide powe r for internal circuits. 1.0 f should be connected between the vin pin and gnd. 9 vdc internal ldo output pin. 5v output by regulating fr om vin. maximum output current is 30ma. 1.0 f should be connected between the vdc pin and gnd. 10 ovp over voltage protection detection circuit input pin . the voltage at the ovp pin is the led anode voltage divided by the resistor divider. if t he voltage exceeds 1.2v, the boosted led anode voltage will be suppressed. if the voltage go es below 0.1v, the ovp pin short protection circuit is activated. 11 comp dc/dc boost converter phase compensation pin. a res istor and a capacitor should be connected between the comp pin and gnd. 1 20 htssop20 clko pgood 11 10 ch3 ch2 ch1 tm lx sclk sdata gnd vdc ovp iset vin pgnd pwm rt comp nc sync
AP2152 ms1348-e-00 4 2012/05 pin no. pin name function 12 rt switching frequency set pin. oscillation frequency can be set by connecting a resistor between the rt pin and gnd. please refer to section 2.4 switching frequency setting/function of synchronizing with external clo ck. 13 iset led driving current set pin. led current can be set by connecting a resistor between the iset pin and gnd. please refer to section 2.3 led current setting. 14 tm capacitor connection pin for timer. if an abnormali ty occurs in the ic, this pin outputs 10a constant current. if this pin voltage exceeds 2.0v, the ic ceases its operation. by returning to the standby state, the timer is reset and the ic can be released. when the timer is unnecessary, please connect to gnd. please refer to section 2.6 timer latch (tm) setting. 15 pgood power good pin. n channel open-drain, it keeps off when normal operation. if an abnormality occurs in the ic, the operation is latc hed off by timer latch function and internal fet turns on. please refer to protections description for the detail of power good pin status described later. when the power goo d function is unnecessary, please connect to gnd. 16 nc nc pin. 17 ch3 wleds constant current circuit 3. ch3 is open drain , and provides constant current to the leds. if this constant current channel is unnecessa ry, please keep this pin open. 18 ch2 wleds constant current circuit 2. ch2 is open drain , and provides constant current to leds. if this constant current channel is unnecessa ry, please keep this pin open. 19 ch1 wleds constant current circuit 1. ch1 is open drain , and provides constant current to leds. if this constant current channel is unnecessa ry, please keep this pin open. 20 gnd gnd pin for internal circuits. - thermal pad for heat radiation, connection to gnd is recommende d. this is electrically isolated from the internal cir cuit. absolute maximum ratings rating symbol value unit condition vin voltage v in -0.3 to +45 v *1 lx, ch1-3 voltage v lx , v ch -0.3 to +45 v *1 sdata, sclk, pwm,vdc, pgood, sync voltage - -0.3 to +6 v *1 ovp, comp, rt, iset, tm, clko voltage - -0.3 to (v dc + 0.3) v *1*4 ch1-3 current i ch 140 ma pgood current i good 20 ma power dissipation p d 2500 mw *2, *3 operating temperature range t op -40 ~ +105 c storage temperature range t stg -55 ~ +150 c note: *1. all voltages refer to gnd pin (gnd, pgnd) as ze ro (reference) voltage. *2. pd must be decreased at the rate of 23.3mw/ c for operation above 25 c. *3. mounted on a 50 mm 50 mm x 1 mm double sided fr-4 board. *4. the maximum value is limited to 6.0v if v dc exceeds 5.7v. note the maximum ratings are the absolute limitation val ues with the possibility of damage/breakage. when operation exceeds this standard, quality canno t be guaranteed.
AP2152 ms1348-e-00 5 2012/05 electrical characteristics v in =12v, gnd=pgnd=0v, r iset =36k, r t =91k, pwm=5v, t a =+25 c unless otherwise specified. items marked by are guaranteed by design in the range of -30 to +85 . value parameter symbol min typ max unit condition dc/dc converter input voltage range v in 4.25 35 v supply current(sw on) i dd 5 10 ma standby current i stb 5.0 10 a after start up pwm =0v *1 uvlo voltage v uvlo 3.75 4.0 4.25 v uvlo on v in uvlo hysteresis width v hys_uvlo 0.2 v uvlo off v in 1.86 2.0 2.14 mhz 1.80 2.0 2.17 mhz r t =55k 1.21 1.3 1.39 mhz switching frequency f osc 1.18 1.3 1.42 mhz r t =91k lx on resistance r lx 400 800 m i lx =+30ma lx off leak current i leak_lx 0.1 1.0 a v lx =45v maximum on duty d max 90 95 % f osc =1.3mhz lx minimum on time t lx_min 50 ns comp output high voltage v oh_comp 4.55 4.9 v i comp =-10a comp output low voltage v ol_comp 0.1 0.2 v i comp =+10a 680 800 920 mv error amp reference voltage v ref_ea 600 800 1000 mv r iset =36 k current sink circuit and dimming part led current range i led 10 120 ma 73.15 75.8 78.46 ma r iset =36k 2 i i ) ma ( i min )3 1( ch max )3 1( ch typ _ led ? ? + = i led_typ1 72.39 75.8 79.21 ma r iset =36k 2 i i ) ma ( i min )3 1( ch max )3 1( ch typ _ led ? ? + = 28.8 30.0 31.2 ma r iset =91k 2 i i ) ma ( i min )3 1( ch max )3 1( ch typ _ led ? ? + = i led_typ2 28.5 30.0 31.5 ma r iset =91k 2 i i ) ma ( i min )3 1( ch max )3 1( ch typ _ led ? ? + = led current i led_typ3 62.08 65.0 67.93 ma r iset =42k 2 i i ) ma ( i min )3 1( ch max )3 1( ch typ _ led ? ? + =
AP2152 ms1348-e-00 6 2012/05 electrical characteristics (continuation) value parameter symbol min typ max unit condition i led1 -2.5 0.8 +2.5 % r iset = 36k, i led_typ =75.8ma 100 i i i i (%) i min )3 1( ch max )3 1( ch min )3 1( ch max )3 1( ch led + ? = ? ? ? ? i led2 -5.0 1.5 +5.0 % r iset = 91k, i led_typ =30.0ma 100 i i i i (%) i min )3 1( ch max )3 1( ch min )3 1( ch max )3 1( ch led + ? = ? ? ? ? led current accuracy between channels i led3 -2.5 0.8 +2.5 % r iset = 42k, i led_typ =65.0ma 100 i i i i (%) i min )3 1( ch max )3 1( ch min )3 1( ch max )3 1( ch led + ? = ? ? ? ? tr 1 2 led current rising time to pwm input r t =55k led current delay time tf 0.5 1 s led current falling time to pwm input r t =55k ldo 4.75 5.0 5.25 v output voltage v dc 4.50 5.0 5.50 v v in =12v, i dc =10ma protection function ovp reference voltage v ovp 1.15 1.2 1.25 v led short criterion voltage v sht 10.8 12 13.2 v ch1~ch3 pin lx limited current i lx_limit 2.6 a pgood on resistance r pgood 100 i pgood =+10ma tm voltage v tm 1.9 2.0 2.1 v tm constant output current i tm 8 10 12 a tm=1.0v switching frequency range f osc 0.2 2.5 mhz input high level voltage v ih 2.1 v pwm, sclk, sync input low level voltage v il 0.7 v pwm, sclk, sync clko output high level voltage v oh_clko 4.0 v i clko =-1ma clko output low level voltage v ol_clko 0.3 v i clko =+1ma
AP2152 ms1348-e-00 7 2012/05 *1. normally, when 4.25v is applied to vin for shorter th an 100s, while the pwm pin is kept at a low level, the ic will be in the standby mode. however, if 4.25v is applied to vin for longer than 3 00s, the current consumption of the ic is about 900a. in order to get the ic into standby mode, af ter inputting a h level to the pwm pin for more than 36s , a l level needs to be maintained for more th an 50ms. figure 3. power supply rising time and standby mode interface (ac timing) value parameter symbol min typ max unit condition pwm 15 30 s before startup pwm minimum high time 1 t pwm_min1 15 36 s before startup pwm minimum high time 2 t pwm_min2 5 7 s after startup shutdown time t sd 20 30 50 ms pwm dimming frequency range f pwm 0.1 20 khz f pwm f osc / 65 sync sync input frequency range f sync 0.21 2.5 mhz sync input duty d sync 20 80 % serial timing sclk cycle t sckp 10 s sclk pulse width t sckw 5 s sdata delay t sdtw 3 s sclk sdata tsckp tsckw tsckw tsdtw figure 4. serial interface wave form pwm stan d by mode vin 36 s or longer 4.2 v 0 0 50 ms or longer approx 900 a idd approx 5ma approx 5 a 300 s or longer
AP2152 ms1348-e-00 8 2012/05 operation 1) operation outline the AP2152 is composed of a current mode dc/dc boos t convertor, 3 led constant current source channels, an ldo, and several protection circuits. i t can drive a single led line to three led lines connected together with a common anode. (any unused channel should be left open) this current mode dc/dc boost convertor has a built -in a power mosfet, and the switching frequency is determined by an external resistor or an external clock signal. the led anode voltage is optimized by monitoring each channels voltage and t he channel voltage that has the highest forward voltage is chosen. this voltage is used to control the dc/dc boost convertors output voltage . constan t current circuits for driving the leds are set by an external resistor, and pwm dimming is possible by applying a pwm signal to the pwm pin. the latch-off t ime for the protection circuits, such over current protection, channel short protection, and thermal pro tection can be set. there is also a pgood pin to output the latch-off status. the AP2152 flowchart at startup is shown in figure 5 . when all ch pins are used, applying a pwm signal begin s the dc/dc boost convertor operation. the led anode voltage rises, and if the led current of all the ch reaches 1/10 of the set current, the soft-start circuit is activated and the led current gradually increases in approximately 1ms, and leds are lit. if there are any unused ch pins, the led open detect ion circuit is activated at the beginning of the dc/dc boost converter operation as soon as the pwm s ignal is applied. when the led anode voltage reaches the ovp preset value, the ovp state is detec ted. if a ch pin has not reached 1/10 of the led se t current, an open state is recognized, and the led c onstant current circuit will cease. for ch pins connected to leds, the led current reaches 1/10 of the set current, the normal connection is recognized, and the leds are lit after the soft-sta rt operation. figure 5. flowchart at startup apply power apply pwm reference voltage on. vdc on . power on reset. boost circuit on . c onstant current circuit (1/10 of the set current) on. 1/10 of the set current flows to all 3 ch constant current circuits. vout reaches the ovp voltage. exclude open ch from dc/dc control. operate led current soft start 1 ms normal operation 300 s delay delay time 30 s all ch pin are used (3ch s ) . 1 or 2chs is/are used. when a current is not flowed on the constant current circuit in the ch. initial determination mode boost circuit/constant current circuit operation continues regardless the pwm signal level (high/low). tsw 1920
AP2152 ms1348-e-00 9 2012/05 2) functions 2-1) pwm input circuit the AP2152 achieves pwm dimming by applying a pwm sig nal to the pwm pin. the pwm pin is also used as the enable function of the ic. at startup, if a high level pwm signal is applied to the pwm pin and maintained for more than 36us, the standby mode will be released. if the high leve l of pwm signal within the range of 50hz~20khz(f pwm f osc / 65), is applied longer than 7us to the pwm pin af ter releasing the standby mode, the operation mode is maintained and direct p wm dimming by pwm signal is simultaneously conducted. the led current will be the set current configured by the r iset resistor during a high level of the pwm dimming signal, and the current will be 0ma during a low level of the pwm dimming signal. if a low level pwm signal is maintained longer than 50ms after the led is lit, the ic will be in the standby mode. 2-2) 5v regulator the AP2152 has a built in low dropout linear regulat or to supply voltage for the internal circuits. if a low level is applied to the pwm pin, the vdc is approxim ately 0v, and if a high level is applied to the pwm pin, the vdc outputs 5v. the vdc pin, the output o f the ldo, outputs 5v while the supply voltage ranges from 6v to 35v. if the supply voltage is less than 6v, the output voltage decreases depending on the supply voltage. if the supply voltage goes below t he uvlo voltage, the ic ceases operation. if the supply voltage is between the uvlo voltage and 6v, th e ic operates but the characteristics are not guaranteed. please connect 1uf capacitor between the vdc pin and gnd. 2-3) led current setting the AP2152 has 3 channel led constant current circu its built in. by connecting 10 leds in series per channel, a maximum of 30 leds can be driven. maximu m led current per channel is 120ma. the led current can be set in the range from 10ma to 120ma by connecting an external resistor r iset between the iset pin and gnd. if the iset pin is affected b y noise, the led current becomes unstable, so r iset should be placed as close to the ic as possible. the iset pin sets the led current for all channels. (ch1~ch3) the following shows the approximate expression for the led current and the r iset connected to the iset pin. please check the led current (thoroughly) when designing the actual board. ) k( r 2730 = ) ma ( iled iset 2-4) switching frequency setting/synchronize with e xternal clock the AP2152 can set the dc/dc boost converter switch ing frequency in the range from 0.2mhz to 2.5mhz by connecting an external resistor rt betwee n the r t pin and gnd. if the rt pin is affected by noise, the switching frequency becomes unstable, so r t should be placed as closer to the ic as possible. the AP2152 switching frequency can be synchronized to an external clock signal. if an external clock signal is applied to the sync pin, the switchin g frequency synchronizes to the external clocks rising edge. if a low level is applied to the sync pi n for approximately 10us during the synchronization operation, it becomes self-oscillating. (if low level is applied to the sync pin in the synchr onization operation for approximately 10us, it becomes self-oscillation operation.) the external clock frequency and the switching freq uency set by r t should be the same. the following shows the approximate expression of the switching frequency and r t on the rt pin. please check (thoroughly) when designing the actual board. 80 + ) k( r 695 .7 10 = ) mhz ( f t 3 osc
AP2152 ms1348-e-00 10 2012/05 2-5) over voltage protection (ovp)/ovp pin short pr otection in order not to exceed the internal mosfet breakdow n voltage, the AP2152 has built in over voltage protection . the ovp pin monitors the led anode voltage divided by the resistor divider. if the ovp pin voltage exceeds 1.20v, the ic ceases boost operatio n. the led constant current source maintains operation. if the ovp pin voltage becomes less than 1.20v, the boost operation is resumed. the over current protection function prevents damage by suppressing an overvoltage condition (excessive led anode voltage) when the load is redu ced. this can occur when there is an open condition across one of the led lines or when the s upply voltage fluctuates rapidly. voltage reference ovp ) r r 1( voltage ovp 1 ovp 2 ovp + = ovp reference voltage 1.2v (typ) the ovp set voltage should be set more than the tot al voltage of the maximum forward voltage of the led line plus the error amplifier reference voltage t o correctly detect an led open condition. however the total voltage needs to be less than the nch powe r mosfet maximum rating voltage. the ovp pin short protection is built in. it is activ ated when the ovp pin voltage becomes less than 0.1v, which is caused by an open across the external schottkey diode. if the ovp pin short protection is activated, the boost dc/dc convertor operation and t he led constant current circuit ceases, the internal fet for pgood is turned on. 2-6) timer latch (tm pin) setting the AP2152 has a built in timer latch type protection circuit. the latch time for the protection circuit is set by connecting an external capacitor c tm between the tm pin and gnd. when channel short protection, over current protection, ovp pin short pro tection, or thermal protection is activated, c tm which is connected to the tm pin is charged by a 10u a constant current. however, the tm pin becomes hi-z (high impedance) while pwm = low and the tm pin voltage is maintained. when the protection circuits continue their operation , the charging of c tm also continues. if the tm pin voltage reaches 2.0v, the dc/dc boost convertor and the led constant current circuits are latched off and the internal fet for pgood is turned on. in order to restart the ic after it has been turned off by the timer latch function, a low level for m ore than 50ms needs to be maintained on the pwm pin or the supply voltage needs to be pulled down below the uvlo voltage. the following shows the approximate expression of the timer latch time and c tm connected on the tm pin. please check (thoroughly) when designing the ac tual board. timer latch time )f ( c 200 = ) ms ( t tm tm 2-7) thermal protection the AP2152 has a built in thermal protection circuit . if the ic goes into and maintains a high temperature state, the ic will be latched off, there fore the ic needs to be operating below the thermal protection circuit minimum (activation) temperature of 125 c. 2-8) led open protection the AP2152 can be operated with one, two or three ch annels connected. there is not a problem if a ch pin is left open. . for this operation, the AP2152 has a built in led ope n detection circuit. if an open ch pin is detected, the ch pin becomes a high impedance and is excluded f rom the control circuit of the dc/dc boost converter. if all three ch pins are open, the dc/dc boost conve rter and the led constant current circuits are completely turned off. if a capacitor is connected in parallel with the led line and the led line is opened, the open detection circuit may not work corre ctly.
AP2152 ms1348-e-00 11 2012/05 2-9) led short protection and cout setting the AP2152 has a built in led short protection circu it. if an led is broken as a short state and the ch pin voltage exceeds 10.8v, the corresponding constant current circuit will be ceased. if there is an unused ch pin, the led anode voltage increases up to the ovp setting voltage by the led open detection circuit. in this case, the ch pin temporarily increases and becomes the same state as the led short protection, in order to distinguish this case from led short protection operation, the opened ch pin is excluded using the ic internal coun ter. for this operation, the cout value is constrained, so cout should be determined using the following formula. led short protection count time ch pin voltage rising time (10.8v or higher) led short protection count time 1920 fsw 1 = 95 .0 iout ) v 8. 10 ) min ( ledvf ) max vp( vo ( cout time rising voltage pin ch = 2-10) pgood function the pgood pin is an nch open drain output. the interna l fet on the pgood pin stays off when the supply voltage is 0v (if the pgood pin is connected to a pull-up resistor, the pgood pin becomes high level) if the supply voltage reaches to approximately 2 v, the internal circuits are biased and the internal pgood fet turns on. if the supply voltage i s more than uvlo and the pwm pin is high, the standby circuit will be released, the ic recognizes as normal operation and the internal pgood fet turns off. if a protection circuit is activated afte r normal operation, the internal pgood turns on. (relationship between protection function and the pg ood pin state is later described in protection function). by applying a pwm low level for longer th an 50ms, the ic will be reset and the internal pgood fet turns on in a standby state. when the led anode is shorted to gnd, the internal pgood fet immediately is turned on by the ovp pin short circuit protection and the pgood signal can be used to cut the path from vin to the led anode. (refer to figure 7) the AP2152 employs a timer latch method for protectio n functions. if the fet over current protection, thermal protection, ch short protection, led open prote ction, or led short protection is activated, the ic is latched off and turns off the leds. for example, when the pgood pin is monitored by a mic rocomputer and an abnormal state (pgood pin with pull-up resistor is low level) is detected, t he microcomputer controls a restart sequence after the ic is reset, so a highly stable system configur ation is possible.
AP2152 ms1348-e-00 12 2012/05 internal nch fet on pgood pin operation turn off during normal operation turn on when abnormal operation timer latch off (over current, ch short, thermal pr otection), all ch are open or short, uvlo turn on when in standby state while supply voltage (vin) is applied. turn off when vin is less than 2v turn on without delay by timer circuit when ovp pin short is detected. figure6. pgood pin operation figure7. cut off vin-led anode path by using an ex ternal fet (example) vpwm vin vin pwm initial determination 1 / 10 * iled iled led setting current 30ms typ 1 ms led current soft start pgood pgood pgood pgood on off off on about 2v off about2v 0 . 3 ms typ vin 8 lx 15 pgood c in 2 c out 2 l d c out 1 c in 1 vin 1 led anode 3 . 3 v
AP2152 ms1348-e-00 13 2012/05 2-11) serial interface the AP2152 has a built in read only serial interfac e. by inputting a clk signal to the sclk pin, data can be read from the sdata pin synchronizing with th e clk rising edge. the sdata pin is an nch open drain output. the pin needs to be pulled-up to the external power supply. sdata state ch1 low led open or short ? ch1 shutoff ch2 low led open or short ? ch2 shutoff ch3 low led open or short ? ch2 shutoff tm low shut-off state by timer latch sclk sdata ch1 ch2 ch3 tm reset ch1 figure8. serial interface timing chart
AP2152 ms1348-e-00 14 2012/05 3) protection function protection description detection time shut-off state detection condition release condition pgood thermal when the ic temperature rises and reaches the detection condition and exceeds the detection time, the dc/dc boost converter and the led constant current circuit are latched off. t tm *2 latch off 125 min *1 on over current internal nch power mosfet drain current is monitored by using an internal detection resistor. if exceeding the detection condition, the power mosfet is turned off. and if exceeding the detection time, the dc/dc boost converter and the led constant current circuit are latched off. t tm *2 latch off 2.6a *1 on over voltage (ovp) if the ovp pin voltage reaches the detection condition, the dc/dc boost converter is immediately shut off. in this case, the led constant current circuit is still operating led anode voltage control auto-release more than 1.2v 1.2v or less off ovp pin short if the ovp pin reaches the detection condition caused by the ovp pin shorted to gnd, the led anode shorted to gnd or the schottky diode open, the dc/dc boost converter and the led constant current circuit are immediately shut off and the internal pgood fet is turned on. if the ovp pin voltage reaches the release condition, normal operation is resumed. if exceeding the detection time, the dc/dc boost converter and the led constant current circuit are latched off. cease all auto-release t tm *2 latch off lass than 0.1v more than 0.1v *1 on uvlo to prevent malfunction of the ic when the vin voltage reaches the detection condition. circuits excluding the uvlo circuit stop the operation. if the vin voltage returns to the release condition, the ic resumes normal operation. cease all auto-release 3.75vmin 4.45vmax on ldo short to prevent malfunction and over heating of the ic when the vdc pin shorts to gnd. the ldo current is limited to low levels. if the short stat e goes away, the ic resumes normal operation. cease all auto-release more than 30ma 30ma or less off ch short when the ch pin shorts to gnd, the voltage reaches the detection condition, and exceeds the detection time, the dc/dc boost converter and the led constant current are ceased. t tm *2 latch off 0.1v *1 on led open if the ch pin is opened due to an led disconnection or destruction as an open state, the ch pin is latched off. internal timer each ch latch off less than led set current when ovp voltage *1 off *3 led short if the ch pin voltage reaches the detection condition due to destruction by an led short, the ch pin is latched off. internal timer each ch latch off 12v *1 off *4 iset short to prevent heat generation due to increases in the led current when the iset pin shorts to gnd, the nch power mosfet operation is ceased. if the short state goes away, the ic resumes the normal operation. cease nch power mosfet auto-release iset pin gnd short iset pin normal 1v off rt short to prevent heat generation due to increases in the switching frequency when the rt pin shorts to gnd, the nch power mosfet operation is ceased. if the short state goes away, the ic resumes the normal operation. cease nch power mosfet auto-release rt pin gnd short rt pin normal 1v off note: *1. in order to release the latch off state, the pw m pin should be maintained at a low level for 50ms or longer or the supply voltage should be pulled down less than the uvlo voltage. *2. set time by external capacitor on the tm pin. r efer to the timer latch setting. *3. off when 1 ch or 2 chs out of 3 chs is/are open state, on when all 3 chs are open state. *4. off when 1 ch or 2 chs out of 3 chs is/are shor t state, on when all 3 chs are short state.
AP2152 ms1348-e-00 15 2012/05 application (example) input voltage vin=8.5v~16v led 2 lines in parallel led anode voltage 9 leds in series 22.3v-32.6v led current 55ma/line 17 ch3 18 ch2 19 ch1 ovp vin vdc tm rt iset gnd 20 10 14 8 9 5 12 pwm 11 comp 4 3 sclk sdata lx pgnd 1 2 6 4 sync clko 15 pgood c in2 c out2 l d c out1 c in1 r ovp2-1 vo ut r iset r t r syn c c vdc c tm c comp 2 pwm inpu t r ovp1 13 vin r ovp2-2 c comp 1 r comp figure 9. external circuit connection example a recommended bom symbol p/n value maker note r t - 55k 0.5% - sw frequency 2mhz r ovp1 - 30k 0.5% - ovp voltage 37.2v r ovp2-1 - 430k 0.5% - ovp voltage 37.2v r ovp2-2 - 470k 0.5% - ovp voltage 37.2v r iset - 49.7k 0.5% - led current 55ma r comp - 1k 1% - phase compensation resistor r sync short 0 - self resonant freq. c in1 grm31cr71h475k 4.7uf/50v murata input capacitor c in2 cm21x5r105m50a 1.0uf/50v kyocera capacitor for the ic c vdc cm05x5r105m06a 1.0uf/6.3v kyocera for vdc stabilit y c tm cm05x5r104m10a 0.1uf/10v kyocera timer latch setti ng c comp1 cm05x5r473m16a 0.047uf/16v kyocera phase compensat ion c comp2 open - - - capacitor c out1 , 2 grm31cr71h225k 2.2uf/50v murata output capacitor diode d - 60v io=1a - inductor l #a921cy-150m d63lcb 15uh toko values in this table are for reference only.
AP2152 ms1348-e-00 16 2012/05 characteristics ta=25 c, pwm=3.3v (reference only) led current vs. supply voltage led current vs. pwm duty vin=12v pwm 200hz vin vs. led current 50 52 54 56 58 60 8 10 12 14 16 vin(v) iled (ma) iled_ch1 iled_ch2 pwm signal duty vs. iled 0 10 20 30 40 50 60 0 20 40 60 80 100 pwm signal duty(% ) iled (ma) iled_ch1 iled_ch2 efficiency vs. supply voltage phase margin vin=12v vin vs. efficiency 65 70 75 80 85 90 95 8 9 10 11 12 13 14 15 16 vin(v) efficiency(%) start-up wave form vin=12v pwm duty 100% start-up wave form vin=12v pwm duty 0.8% 200hz
AP2152 ms1348-e-00 17 2012/05 package and marking 1) dimension 20 pin htssop 4.4 0. 1 20 11 10 1 6.5 0.235 1.0 0.10 1.20 max 0.1 6.4 0 . 1 4 0.2 0.65 0.10 m 0.10 0 . 1 reference mount pad 0.8 0.375 0.65 3.2 4 . 3 2 0 ~ 1 0 0.60 0 . 1 0 . 0 5 s s 0 . 0 3 5 0.04 3.0 4 . 1 2 mark lot no 5.7 date code 0.25
AP2152 ms1348-e-00 18 2012/05 2) marking upper product name AP2152 center assembly lot number: 3 digits lower date code: 4 digits 1 digit (last digit of year) + 2 digits (weekly cod e) + 1 digit (lot number) important notice these products and their specifications are subject to change without notice. when you consider any use or application of these p roducts, please make inquiries the sales office of asahi kasei microdevices corporation (akm) or authorized distri butors as to current status of the products. descriptions of external circuits, application circ uits, software and other related information contai ned in this document are provided only to illustrate the operat ion and application examples of the semiconductor p roducts. you are fully responsible for the incorporation of thes e external circuits, application circuits, software and other related information in the design of your equipments. akm a ssumes no responsibility for any losses incurred by you or third parties arising from the use of these informa tion herein. akm assumes no liability for infringem ent of any patent, intellectual property, or other rights in t he application or use of such information contained herein. any export of these products, or devices or systems containing them, may require an export license or other official approval under the law and regulations of the count ry of export pertaining to customs and tariffs, cur rency exchange, or strategic materials. akm products are neither intended nor authorized fo r use as critical components note1) in any safety, life support, or other hazard related device or system note2) , and akm assumes no responsibility for such use, e xcept for the use approved with the express written consent by repres entative director of akm. as used here: note1) a critical component is one whose failure to functi on or perform may reasonably be expected to result, whether directly or indirectly, in the loss of the safety o r effectiveness of the device or system containing it, and which must therefore meet very high standards of performance a nd reliability. note2) a hazard related device or system is one designed o r intended for life support or maintenance of safet y or for applications in medicine, aerospace, nuclear energy , or other fields, in which its failure to function or perform may reasonably be expected to result in loss of life or in significant injury or damage to person or prope rty. it is the responsibility of the buyer or distributo r of akm products, who distributes, disposes of, or otherwise places the product with a third party, to notify such thir d party in advance of the above content and conditi ons, and the buyer or distributor agrees to assume any and all r esponsibility and liability for and hold akm harmle ss from any and all claims arising from the use of said product in the absence of such notification. AP2152 xxxx xxx

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