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2ch pwm dc/dc controller r1280d002x series 2001.6.16 rev. 1.10 - 1 - outline the r1280d002x series are 2-channel pwm step-up (as channel 1)/inverting (as channel 2) dc/dc converter controllers with cmos process. each of the r1280d002x series consists of an oscillator, a pwm control circuit, a reference voltage unit, an error amplifier, a reference current unit, a protection circuit, and an under voltage lockout (uvlo) circuit. a high efficiency step-up/inverting dc/dc converter can be composed of this ic with inductors, diodes, power mosfets, resisters, and capacitors. each output voltage can be adjustable with external resistors, while soft-start time can be adjustable with external capacitors.. maximum duty cycle of r1280d002a and c series can be also adjustable with external resistors. maximum duty cycle of r1280d002b is built-in as 90%(typ.). when ce pin of r1280d002b is set at gnd level, this ic turns off external power mosfets of step-up/inverting as standby-mode. standby current is typically 0 a. as for a protection circuit, if maximum duty cycle of either step-up dc/dc converter side or inverting dc/dc converter side is continued for a certain time, the r1280d series latch both external drivers with their off state by its latch-type protection circuit. delay time for protection is internally fixed typically at 100ms. to release the protection circuit, restart with power-on (voltage supplier is equal or less than uvlo detector threshold level), or as for r1280d002b, once after making the circuit be stand-by with chip enable pin and enable the circuit again. features input voltage range ? ? ? ? ? ? ? ? ? ? ? ? ? 2.5v to 5.5v built-in latch-type protection function by monitoring duty cycle (fixed delay time typ. 100ms) oscillator frequency ? ? ? ? ? ? ? ? ? ? ? ? ? 700khz(r1280d002a,b)/200khz(r1280d002c) maximum duty cycle ? ? ? ? ? ? ? ? ? ? ? ? ? typ. 90%(only applied to r1280d002b series) high reference voltage accuracy ? ? ? ? ? ? 1.5% u.v.l.o. threshold ? ? ? ? ? ? ? ? ? ? ? typ. 2.2v (hysteresis: typ. 0.1v) small package ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? thin son-10 (package thickness max. 0.9mm) applications constant voltage power source for portable equipment. constant voltage power source for lcd and ccd.
rev.1.10 - 2 - block diagram r1280d002a/c v in ext1 osc vref1 latch dtc2 v fb2 vrefout ext2 uvlo gnd a mpout1 v fb1 vrefout dtc1 dela y circuit ch ch r1280d002b v in ext1 osc vref1 latch dtc2 v fb2 vrefout ext2 uvlo gnd ce v fb1 vrefout dtc1 dela y circuit chip enable ch1 ch
rev. 1.10 - 3 - selection guide the mask option for the ics can be selected at the user's request. the selection can be made with designating the part number as shown below; r1280d002x-tr part number a b code contents a designation of mask option : a version: fosc=700khz, with external phase compensation for channel 1. b version: fosc=700khz, with internal phase compensation and standby mode. c version: fosc=200khz, with external phase compensation for channel 1 b designation of taping type : (refer to taping specifications.) pin configuration son10 10 6 1 5 ( mark side ) pin description r1280d002a/c pin no. symbol description 1 ext1 external transistor of channel 1 drive pin (cmos output) 2 gnd ground pin 3 ampout1 amplifier output pin of channel 1 4 dtc1 maximum duty cycle of channel 1 setting pin 5v fb1 feedback pin of channel 1 6v fb2 feedback pin of channel 2 7 dtc2 maximum duty cycle of channel 2 setting pin 8 vrefout reference output pin 9v in voltage supply pin of the ic 10 ext2 external transistor of channel 2 drive pin (cmos output)
rev.1.10 - 4 - r1280d002b pin no. symbol description 1 ext1 external transistor of channel 1 drive pin (cmos output) 2 gnd ground pin 3 ce chip enable pin 4 dtc1 maximum duty cycle of channel 1 setting pin 5v fb1 feedback pin of channel 1 6v fb2 feedback pin of channel 2 7 dtc2 maximum duty cycle of channel 2 setting pin 8 vrefout reference output pin 9v in voltage supply pin of the ic 10 ext2 external transistor of channel 2 drive pin (cmos output) absolute maximum ratings r1280d002a/c symbol item rating unit v in v in pin voltage 6.5 v v ext1,2 v ext1,2 pin output voltage -0.3 v in +0.3 v v ampout1 ampout1 pin voltage -0.3 v in +0.3 v v dtc1,2 dtc1,2 pin voltage -0.3 v in +0.3 v v refout v refout pin voltage -0.3 v in +0.3 v v fb1,2 v fb1 ,v fb2 pin voltage -0.3 v in +0.3 v i ext1,2 ext1,2 pin output current 50 ma p d power dissipation 250 mw topt operating temperature range -40 to +85 c tstg storage temperature range -55 to +125 c r1280d002b symbol item rating unit v in v in pin voltage 6.5 v v ext1,2 v ext1,2 pin output voltage -0.3 v in +0.3 v v ce ce pin voltage -0.3 v in +0.3 v v dtc1,2 dtc1,2 pin voltage -0.3 v in +0.3 v v refout v refout pin voltage -0.3 v in +0.3 v v fb1,2 v fb1 ,v fb2 pin voltage -0.3 v in +0.3 v i ext1,2 ext1,2 pin output current 50 ma p d power dissipation 250 mw topt operating temperature range -40 to +85 c tstg storage temperature range -55 to +125 c
rev. 1.10 - 5 - electrical characteristics r1280d002a (topt=25 c) symbol item conditions min. typ. max. unit v in operating input voltage 2.5 5.5 v v refout v refout voltage tolerance v in =3.3v, i out =1ma 1.478 1.500 1.522 v i rout v refout output current v in =3.3v 20 ma ? vrefout / ? v in v refout line regulation 2.5v v in 5.5v 26 mv ? vrefout / ? i out v refout load regulation 1ma i rout 10ma v in =3.3v 612 mv i lim v refout short current limit v in =3.3v, v refout =0v 25 ma ? vrefout / ? t v refout voltage temperature coefficient -40 c topt 85 c 150 ppm/ c v fb1 v fb1 voltage v in =3.3v 0.985 1.000 1.015 v ? vfb1 / ? t v fb1 voltage temperature coefficient -40 c topt 85 c 150 ppm/ c i fb1,2 i fb1,2 input current v in =5.5v,v fb1 or v fb2 =0v or 5.5v -0.1 0.1 a f osc oscillator frequency ext1,2 pins at no load, v in =3.3v 595 700 805 khz i dd1 supply current v in =5.5v, ext1,2 pins at no load 1.4 3.0 ma r exth1 ext1 ?h? on resistance v in =3.3v, i ext =-20ma 4.0 8.0 ? r extl1 ext1 ?l? on resistance v in =3.3v, i ext =20ma 2.7 5.0 ? r exth2 ext2 ?h? on resistance v in =3.3v, i ext =-20ma 4.0 8.0 ? r extl2 ext2 ?l? on resistance v in =3.3v, i ext =20ma 3.7 8.0 ? t dly delay time for protection v in =3.3v, v fb1 =1.1v 0v 60 100 140 ms v uvlod uvlo detector threshold 2.10 2.20 2.35 v v uvlo uvlo released voltage v uvlod +0.10 2.45 v v dtc10 ch1 duty=0% v in =3.3v 0.1 0.2 0.3 v v dtc1100 ch1 duty=100% v in =3.3v 1.1 1.2 1.3 v v dtc20 ch2 duty=0% v in =3.3v 0.1 0.2 0.3 v v dtc2100 ch2 duty=100% v in =3.3v 1.1 1.2 1.3 v a v1 ch1 open loop gain v in =3.3v 110 db f t1 ch1 single gai n frequency band v in =3.3v, a v1 =0db 1.9 mhz v icr1 ch1 input voltage range v in =3.3v 0.7 to v in v i ampl ch1 sink current v in =3.3v, v ampout1 =1.0v, v fb1 =v fb1 + 0.1v 70 115 a i amph ch1 source current v in =3.3v, v ampout1 =1.0v, v fb1 =v fb1- 0.1v -1.4 -0.7 ma a v2 ch2 open loop gain v in =3.3v 60 db f t1 ch2 single gain frequency band v in =3.3v, a v2 =0db 3 mhz v icr1 ch2 input voltage range v in =3.3v, -0.2 to v in -1.3 v v fb2 ch2 input offset voltage v in =3.3v, -12 12 mv
rev.1.10 - 6 - r1280d002b (topt=25 c) symbol item conditions min. typ. max. unit v in operating input voltage 2.5 5.5 v v refout v refout voltage tolerance v in =3.3v, i out =1ma 1.478 1.500 1.522 v i rout v refout output current v in =3.3v 20 ma ? vrefout / ? v in v refout line regulation 2.5v v in 5.5v 26 mv ? vrefout / ? i out v refout load regulation 1ma i rout 10ma v in =3.3v 612 mv i lim v refout short current limit v in =3.3v, v refout =0v 25 ma ? vrefout / ? t v refout voltage temperature coefficient -40 c topt 85 c 150 ppm/ c v fb1 v fb1 voltage v in =3.3v 0.985 1.000 1.015 v ? vfb1 / ? t v fb1 voltage temperature coefficient -40 c topt 85 c 150 ppm/ c i fb1,2 i fb1,2 input current v in =5.5v,v fb1 or v fb2 =0v or 5.5v -0.1 0.1 a f osc oscillator frequency ext1,2 pins at no load, v in =3.3v 595 700 805 khz i dd1 supply current v in =5.5v, ext1,2 pins at no load 1.4 3.0 ma maxdty maximum duty cycle v in =3.3v, c dtc1,2= 1000pf 84 90 95 % r exth1 ext1 ?h? on resistance v in =3.3v, i ext =-20ma 4.0 8.0 ? r extl1 ext1 ?l? on resistance v in =3.3v, i ext =20ma 2.7 5.0 ? r exth2 ext2 ?h? on resistance v in =3.3v, i ext =-20ma 4.0 8.0 ? r extl2 ext2 ?l? on resistance v in =3.3v, i ext =20ma 3.7 8.0 ? t dly delay time for protection v in =3.3v, v fb1 =1.1v 0v 60 100 140 ms tss1 soft start time1 for ch1 v in =3.3v, c dtc1 =0.33 f 10 ms tss2 soft start time2 for ch2 v in =3.3v, c dtc2 =0.33 f 15 ms v ceh ce ?h? input voltage v in =5.5v 1.5 v v cel ce ?l? input voltage v in =2.5v 0.3 v v uvlod uvlo detector threshold 2.10 2.20 2.35 v v uvlo uvlo released voltage v uvlod +0.10 2.45 v i ceh ce ?h? input current v in = v ce =5.5v -0.1 0.1 a i cel ce ?l? input current v in =5.5v, v ce =0.0v -0.1 0.1 a i stb standby current v in =5.5v, v ce =0.0v 0 2 a v off2 input offset voltage of ch2. v in =3.3v -12 12 mv
rev. 1.10 - 7 - r1280d002c (topt=25 c) symbol item conditions min. typ. max. unit v in operating input voltage 2.5 5.5 v v refout v refout voltage tolerance v in =3.3v, i out =1ma 1.478 1.500 1.522 v i rout v refout output current v in =3.3v 20 ma ? vrefout / ? v in v refout line regulation 2.5v v in 5.5v 26 mv ? vrefout / ? i out v refout load regulation 1ma i rout 10ma v in =3.3v 612 mv i lim v refout short current limit v in =3.3v, v refout =0v 25 ma ? vrefout / ? t v refout voltage temperature coefficient -40 c topt 85 c 150 ppm/ c v fb1 v fb1 voltage v in =3.3v 0.985 1.000 1.015 v ? vfb1 / ? t v fb1 voltage temperature coefficient -40 c topt 85 c 150 ppm/ c i fb1,2 i fb1,2 input current v in =5.5v,v fb1 or v fb2 =0v or 5.5v -0.1 0.1 a f osc oscillator frequency ext1,2 pins at no load, v in =3.3v 160 200 240 khz i dd1 supply current v in =5.5v, ext1,2 pins at no load 0.7 1.2 ma r exth1 ext1 ?h? on resistance v in =3.3v, i ext =-20ma 4.0 8.0 ? r extl1 ext1 ?l? on resistance v in =3.3v, i ext =20ma 2.7 5.0 ? r exth2 ext2 ?h? on resistance v in =3.3v, i ext =-20ma 4.0 8.0 ? r extl2 ext2 ?l? on resistance v in =3.3v, i ext =20ma 3.7 8.0 ? t dly delay time for protection v in =3.3v, v fb1 =1.1v 0v 50 100 150 ms v uvlod uvlo detector threshold 2.10 2.20 2.35 v v uvlo uvlo released voltage v uvlod +0.10 2.45 v v dtc10 ch1 duty=0% v in =3.3v 0.15 0.25 0.35 v v dtc1100 ch1 duty=100% v in =3.3v 1.1 1.2 1.3 v v dtc20 ch2 duty=0% v in =3.3v 0.15 0.25 0.35 v v dtc2100 ch2 duty=100% v in =3.3v 1.1 1.2 1.3 v a v1 ch1 open loop gain v in =3.3v 110 db f t1 ch1 single gain frequency band v in =3.3v, a v1 =0db 1.9 mhz v icr1 ch1 input voltage range v in =3.3v 0.7 to v in v i ampl ch1 sink current v in =3.3v, v ampout1 =1.0v, v fb1 =v fb1 + 0.1v 70 115 a i amph ch1 source current v in =3.3v, v ampout1 =1.0v, v fb1 =v fb1- 0.1v -1.4 -0.7 ma a v2 ch2 open loop gain v in =3.3v 60 db f t1 ch2 single gain frequency band v in =3.3v, a v2 =0db 3 mhz v icr1 ch2 input voltage range v in =3.3v, -0.2 to v in-1.3 v v fb2 ch2 input offset voltage v in =3.3v, -12 12 mv
rev.1.10 - 8 - operation of step-up dc/dc converter and output current step-up dc/dc converter makes higher output voltage than input voltage by releasing the energy accumulated during on time of lx transistor on input voltage. inductor diode c l lx tr v in v out i out ilxmax ilxmin ton toff t=1/fosc tf il discontinuous mode t ilxmax ilxmin ton toff t=1/fosc t il iconst continuous mode gnd i1 i2 step 1. lx tr. is on, then the current il=i1 flows, and the energy is charged in l. in proportion to the on time of lx tr. (ton), il=i1 increases from il=ilxmin=0 and reaches ilxmax. step 2. when the lx tr. is off, l turns on schottky diode (sd), and il=i2 flows to maintain il=ilxmax. step 3. il=i2 gradually decreases, and after tf passes, il=ilxmin=0 is true, then sd turns off. note that in the case of the continuous mode, before il=ilxmin=0 is true, toff passes, and the next cycle starts, then lx tr. turns on again. in this case, ilxmin>0, therefore il=ilxmin>0 is another starting point and ilx max increases. with the pwm controller, switching times during the time unit are fixed. by controlling ton, output voltage is maintained. output current and selection of external components output current of step-up circuit and external components there are two modes, or discontinuous mode and continuous mode for the pwm step-up switching regulator depending on the continuous characteristic of inductor current. during on time of the transistor, when the voltage added on to the inductor is described as v in , the current is v in t/l. therefore, the electric power, p on , which is supplied with input side, can be described as in next formula. t on p on = v in 2 t/l dt formula 1 0 with the step-up circuit, electric power is supplied from power source also during off time. in this case, input current is described as (v out -v in ) t/l, therefore electric power, p off is described as in next formula.
rev. 1.10 - 9 - tf p off = v in (v out -v in ) t/l dt formula 2 0 in this formula, tf means the time of which the energy saved in the inductance is being emitted. thus average electric power, p av is described as in the next formula. t on tf p av =1/(ton+toff) { v in 2 t/l dt + v in (v out -v in ) t/l dt} formula 3 0 0 in pwm control, when tf=toff is true, the inductor current becomes continuos, then the operation of switching regulator becomes continuous mode. in the continuous mode, the deviation of the current is equal between on time and off time. v in ton/l=(v out -v in ) toff/l formula 4 further, the electric power, p av is equal to output electric power, v out i out , thus, i out = f osc v in 2 t on 2 /{2 l (v out -v in )}=v in 2 t on /(2 l v out )formula 5 when i out becomes more than formula 5, the current flows through the inductor, then the mode becomes continuous. the continuous current through the inductor is described as iconst, then, i out = f osc v in 2 t on 2 /(2 l (v out -v in ))+v in iconst/v out formula 6 in this moment, the peak current, ilxmax flowing through the inductor and the driver tr. is described as follows: ilxmax = iconst +v in ton/l formula 7 with the formula 4,6, and ilxmax is, ilxmax = v out /v in i out +v in ton/(2 l) formula 8 therefore, peak current is more than i out . considering the value of ilxmax, the condition of input and output, and external components should be selected. in the formula 7, peak current ilxmax at discontinuous mode can be calculated. put iconst=0 in the formula. the explanation above is based on the ideal calculation, and the loss caused by lx switch and external components is not included. the actual maximum output current is between 50% and 80% of the calculation. especially, when the ilx is large, or v in is low, the loss of v in is generated with the on resistance of the switch. as for v out, vf (as much as 0.3v) of the diode should be considered. operation of inverting dc/dc converter and output current inverting dc/dc converter saves energy during on time of lx transistor, and supplies the energy to output during off time, output voltage opposed to input voltage is obtained. lx tr inductor diode cl v in v out i out gnd i1 i2
rev.1.10 - 10 - ilxmax ilxmin to n to ff t=1/fosc tf il discontinuous mode t ilxmax ilxmin to n to ff t=1/fosc t il iconst continuous mode step 1. lx tr. turns on, current, il=i1 flows, energy is charged in l. in proportion to the on time, ton, of lx tr. il=i1 increases from il=ilxmin=0 and reaches ilxmax. step 2. when the lx tr. turns off, l turns on shottky diode (sd) and flow il=i2 to maintain il = ilxmax. step 3. il=i2 decreases gradually, after tf passes, il=ilxmin=0 is true, then sd turns off. note that in the case of continuous mode, before il=ilxmin=0 is true, toff passes and next cycle starts, then lx tr. turns on. in this case, ilxmin>0, therefore il increases from il=ilxmin>0. with the pwm controller, switching time (fosc) in the time unit is fixed, and by controlling ton, output voltage is maintained. output current and selection of external components there are also two modes, or discontinuous mode and continuous mode for the pwm inverting switching regulator depending on the continuous characteristic of inductor current. during on time of the transistor, when the voltage added on to the inductor is described as v in , the current is v in t/l. therefore, the electric power, p, which is supplied with input side, can be described as in next formula. t on p= v in 2 t/l dt formula 9 0 thus average electric power in one cycle, p av is described as in the next formula. t on p av =1/(ton +toff) v in 2 t/l dt =v in 2 ton 2 /(2 l (ton + toff)) formula 10 0 this electric power p av equals to output electric power v out i out, thus, i out = f osc v in 2 t on 2 /(2 l v out )formula 11 when i out becomes more than formula 11, the current flows through the inductor continuously, then the mode becomes continuous. in the continuous mode, the deviation of the current equals between ton and toff, therefore, v in ton/l=v out toff/l formula 12 in this moment, the current flowing continuously through l, is assumed as iconst, i out is described as in the next formula: i out = f osc v in 2 t on 2 /(2 l v out )+ton/(ton + toff) v in iconst /v out formula 13 in this moment, the peak current, ilxmax flowing through the inductor and the driver tr. is described as follows: ilxmax = iconst +v in ton/l formula 14 with the formula 12,13, ilxmax is, ilxmax = (ton+toff)/toff i out +v in ton/(2 l) formula 15 therefore, peak current is more than i out . considering the value of ilxmax, the condition of input and output, and external components should be selected. in the formula 14, peak current ilxmax at discontinuous mode can be calculated. put iconst=0 in the formula. the explanation above is based on the ideal calculation, and the loss caused by lx switch and external components is not included. the actual maximum output current is between 50% and 80% of the calculation. especially, when the ilx is large, or v in is low, the loss of v in is generated with the on resistance of the switch. as for v out, vf (as much as 0.3v) of the diode should be considered.
rev. 1.10 - 11 - test circuits test circuit 1 test circuit 2 c1 c2 ext1 ext2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope c1 c2 ext1 ext 2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 osc illosc ope test circuit 3 test circuit 4 c1 c2 ext1 ext2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope c1 c2 ext1 ext 2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope test circuit 5 test circuit 6 ext1 ext2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 v c1 c2 ext1 ext2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 a v c1 c2 test circuit 7 test circuit 8 c1 c2 ext1 ext2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope c1 ext1 ext 2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 os c illosc o pe
rev.1.10 - 12 - test circuit 9 test circuit 10 a c1 c2 ext1 ext2 gnd v in ampout vrefout dtc1 dtc2 v fb1 v fb2 c1 c2 ext1 ext2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope c3 test circuit 11 test circuit 12 c1 c2 ext1 ext2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope c4 c1 c2 ext1 ext2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope test circuit 13 test circuit 14 c1 c2 ext1 ext2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope ext1 ext2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 v c1 c2 test circuit 15 test circuit 16 ext1 ext2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 a v c1 c2 c1 c2 ext1 ext2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope
rev. 1.10 - 13 - test circuit 17 test circuit 18 c1 c2 ext1 ext2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 oscilloscope oscilloscope ext1 ext 2 gnd v in ce vrefout dtc1 dtc2 v fb1 v fb2 c1 c4 c3 c2 oscilloscope typical characteristics shown in the following pages are obtained with test circuits shown above. r1280d002a/c test circuit 1,2: typical characteristic 4) test circuit 3: typical characteristic 6) test circuit 4: typical characteristic 7) test circuit 5: typical characteristic 8) test circuit 6: typical characteristics 9) 10) test circuit 7: typical characteristic 11) test circuit 8: typical characteristic 12) test circuit 9: typical characteristics 13) 14) r1280d002b test circuit 10,11: typical characteristics 4) 5) test circuit 12: typical characteristic 6) test circuit 13: typical characteristic 7) test circuit 14: typical characteristic 8) test circuit 15: typical characteristics 9) 10) test circuit 16: typical characteristic 11) test circuit 17: typical characteristics 15) 16) test circuit 18: typical characteristics 17) 18) standard circuit example: typical characteristics 1) 2) 3) 19) 20) note) capacitors' values of test circuits capacitors: ceramic type: c1=4.7 f, c2=1.0 f, c3=c4=1000pf efficiency (%) can be calculated with the next formula: =(v out1 i out1 +v out2 i out2 )/(v in i in ) 100
rev.1.10 - 14 - typical characteristics 1) output voltage vs. output current topt=25 c l1=6.8uh,c1=10uf, v out2 =-10v,i out2 =0ma l2=6.8uh,c2=10uf, v out1 =10v,i out1 =0ma r1280d002a 9.90 9.95 10.00 10.05 10.10 0 50 100 150 200 output current i out1 (ma) output voltage v out1 (v) vin=2.5v vin=3.3v vin=5.5v r1280d002a -10.10 -10.05 -10.00 -9.95 -9.90 -200 -150 -100 -50 0 output current i out2 (ma) output voltage v out2 (v) vin=2.5v vin=3.3v vin=5.5v l1=6.8uh,c1=10uf, v out2 =-10v,i out2 =0ma l2=6.8uh,c2=10uf, v out1 =10v,i out1 =0ma r1280d002b 9.90 9.95 10.00 10.05 10.10 0 50 100 150 200 output current i out1 (ma) output voltage v out1 (v) vin=2.5v vin=3.3v vin=5.5v r1280d002b -10.10 -10.05 -10.00 -9.95 -9.90 -200 -150 -100 -50 0 output current i out2 (ma) output voltage v out2 (v) vin=2.5v vin=3.3v vin=5.5v l1=22uh,c1=10uf, v out2 =-10v,i out2 =0ma l2=22uh,c2=10uf, v out1 =10v,i out1 =0ma r1280d002c 9.90 9.95 10.00 10.05 10.10 0 50 100 150 200 output current i out1 (ma) output voltage v out1 (v) vin=2.5v vin=3.3v vin=5.5v r1280d002c -10.10 -10.05 -10.00 -9.95 -9.90 -150 -100 -50 0 output current i out2 (ma) output voltage v out2 (v) vin=2.5v vin=3.3v vin=5.5v
rev. 1.10 - 15 - 2) efficiency vs. output current vin=3.3v, topt=25 c l1=6.8uh,c1=10uf, v out2 =-vout1,i out2 =0ma l2=6.8uh,c2=10uf, v out1 =-vout2,i out1 =0ma r1280d002a 0 10 20 30 40 50 60 70 80 90 0 50 100 150 200 output current i out1 (ma) efficiency (%) vout1=5v vout1=10v vout1=15v r1280d002a 0 10 20 30 40 50 60 70 80 90 -200 -150 -100 -50 0 output current i out2 (ma) efficiency (%) vout2=-5v vout2=-10v vout2=-15v l1=6.8uh,c1=10uf, v out2 =-vout1,i out2 =0ma l2=6.8uh,c2=10uf, v out1 =-vout2,i out1 =0ma r1280d002b 0 10 20 30 40 50 60 70 80 90 0 50 100 150 200 output current i out1 (ma) efficiency (%) vout1=5v vout1=10v vout1=15v r1280d002b 0 10 20 30 40 50 60 70 80 90 -200 -150 -100 -50 0 output current i out2 (ma) efficiency (%) vout2=-5v vout2=-10v vout2=-15v l1=22uh,c1=10uf, v out2 =-vout1,i out2 =0ma l2=22uh,c2=10uf, v out1 =-vout2,i out1 =0ma r1280d002c 0 10 20 30 40 50 60 70 80 90 0 50 100 150 200 output current i out1 (ma) efficiency (%) vout1=5v vout1=10v vout1=15v r1280d002c 0 10 20 30 40 50 60 70 80 90 -150 -125 -100 -75 -50 -25 0 output current i out2 (ma) efficiency (%) vout2=-5v vout2=-10v vout2=-15v
rev.1.10 - 16 - 3) output voltage vs. temperature vin=3.3v l1=6.8uh,c1=10uf l2=6.8uh,c2=10uf r1280d002a 9.0 9.5 10.0 10.5 11.0 -60 -40 -20 0 20 40 60 80 100 temperature topt output voltage v out1 (v) iout=10ma iout=100ma r1280d002a -11.0 -10.5 -10.0 -9.5 -9.0 -60 -40 -20 0 20 40 60 80 100 temperature topt output voltage v out2 (v) iout=-10ma l1=6.8uh,c1=10uf l2=6.8uh,c2=10uf r1280d002b 9.0 9.5 10.0 10.5 11.0 -60 -40 -20 0 20 40 60 80 100 temperature topt output voltage v out1 (v) iout=10ma iout=100ma r1280d002b -11.0 -10.5 -10.0 -9.5 -9.0 -60 -40 -20 0 20 40 60 80 100 temperature topt output voltage v out2 (v) iout=-10ma l1=22uh,c1=10uf l2=22uh,c2=10uf r1280d002c 9.0 9.5 10.0 10.5 11.0 -60 -40 -20 0 20 40 60 80 100 temperature topt output voltage v out1 (v) iout=10ma iout=100ma r1280d002c -11.0 -10.5 -10.0 -9.5 -9.0 -60 -40 -20 0 20 40 60 80 100 temperature topt output voltage v out2 (v) iout=-10ma ( c) ( c) ( c) ( c) ( c) ( c)
rev. 1.10 - 17 - 4) frequency vs. temperature r1280d002a 550 600 650 700 750 800 -60 -40 -20 0 20 40 60 80 100 temperature topt frequency fosc (khz) vin=2.5v vin=3.3v vin=5.5v r1280d002b 550 600 650 700 750 800 -60 -40 -20 0 20 40 60 80 100 temperature topt frequency fosc (khz) vin=2.5v vin=3.3v vin=5.5v r1280d002c 150 170 190 210 230 -60 -40 -20 0 20 40 60 80 100 temperature topt frequency fosc (khz) vin=2.5v vin=3.3v vin=5.5v 5) maximum duty cycle vs. temperature vin=3.3v r1280d002b 86 88 90 92 94 -60 -40 -20 0 20 40 60 80 100 temperature topt maximum duty cycle maxduty1(%) r1280d002b 86 88 90 92 94 -60 -40 -20 0 20 40 60 80 100 temperature topt maximum duty cycle maxduty2 (%) ( c) ( c) ( c) ( c) ( c)
rev.1.10 - 18 - 6) feedback voltage vs. temperature 7) input offset voltage vs. temperature vin=3.3v r1280d002a/b/c 0.97 0.98 0.99 1.00 1.01 1.02 -60 -40 -20 0 20 40 60 80 100 temperature topt feedback voltage v fb1 (v) r1280d002a/b/c -10.0 -5.0 0.0 5.0 10.0 -60 -40 -20 0 20 40 60 80 100 temperature topt input offset voltage v fb2 (mv) 8) vrefout output voltage vs. temperature 9) vrefout output voltage vs. output current vin=3.3v r1280d002a/b/c 1.45 1.47 1.49 1.51 1.53 1.55 -60 -40 -20 0 20 40 60 80 100 temperature topt vrefout voltage(v) r1280d002a/b/c 0 0.3 0.6 0.9 1.2 1.5 1.8 0 102030405060 i rout (ma) vrefout voltage(v) 10) vrefout output voltage vs. output current 11) protection circuit delay time vs. temperature vin=3.3v r1280d002a/b/c 1.498 1.500 1.502 1.504 1.506 1.508 0 5 10 15 20 i rout (ma) vrefout voltage(v) r1280d002a/b/c 60 80 100 120 140 -60 -40 -20 0 20 40 60 80 100 temperature topt protection circuit delay time tdly (ms) ( c) ( c) ( c) ( c)
rev. 1.10 - 19 - 12) duty cycle vs. dtc voltage vin=3.3v, ext=1000pf vin=3.3v, ext=1000pf r1280d002a 0 20 40 60 80 100 0 0.2 0.4 0.6 0.8 1 1.2 1.4 v dtc (v) duty cycle duty(%) r1280d002c 0 20 40 60 80 100 0 0.2 0.4 0.6 0.8 1 1.2 1.4 v dtc (v) duty cycle duty(%) 13) output sink current vs. temperature 14) output source current vs. temperature vin=3.3v vin=3.3v r1280d002a/c 90 100 110 120 130 -60 -40 -20 0 20 40 60 80 100 temperature topt output sink current i ampl (ua) r1280d002a/c -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 -60 -40 -20 0 20 40 60 80 100 temperature topt output sink current i amph (ma) 15) ce "h" input voltage vs. temperature 16) ce "l" input voltage vs. temperature vin=5.5v vin=2.5v r1280d002b 0.25 0.50 0.75 1.00 1.25 -50 0 50 100 temperature topt ce"h" input voltage v ceh (v) r1280d002b 0.25 0.5 0.75 1 1.25 -50 0 50 100 temperature topt ce"l" input voltage v cel (v) ( c) ( c) ( c) ( c)
rev.1.10 - 20 - 17) soft starting time vs. capacitance value vin=3.3v r1280d002b 0 10 20 30 40 0 0.2 0.4 0.6 0.8 1 1.2 capacitance value for soft start(uf) soft starting time t ss1 (ms) r1280d002b 0 10 20 30 40 50 00.20.40.60.811.2 capacitance value for soft start(uf) soft starting time t ss2 (ms) 18) soft starting time vs. temperature vin=3.3v cdtc1=0.33 fcdtc2=0.33 f r1280d002b 0 5 10 15 20 -50 0 50 100 temperature topt soft starting time t ss1 (ms) r1280d002b 0 5 10 15 20 25 30 -50 0 50 100 temperature topt soft starting time t ss2 (ms) 19) load transient response(step-up side) vin=3.3v l1=6.8 h l1=6.8 h r1280d002a 7.5 8 8.5 9 9.5 10 10.5 0 0.0005 0.001 0.0015 0.002 time (sec) output voltage v out1 (v) output current i out (ma) 100 0.1 r1280d002a 8.5 9 9.5 10 10.5 11 11.5 0 0.01 0.02 0.03 0.04 0.05 time (sec) output voltage v out1 (v) output current i out (ma) 100 0.1 ( c) ( c)
rev. 1.10 - 21 - l1=6.8 h l1=6.8 h r1280d002b 7.5 8 8.5 9 9.5 10 10.5 0 0.0005 0.001 0.0015 0.002 time (sec) output voltage v out1 (v) output current i out (ma) 100 0.1 r1280d002b 8.5 9 9.5 10 10.5 11 11.5 0 0.01 0.02 0.03 0.04 0.05 time (sec) output voltage v out1 (v) output current i out (ma) 100 0.1 l1=22 h l1=22 h r1280d002c 7.5 8 8.5 9 9.5 10 10.5 0 0.0005 0.001 0.0015 0.002 time (s) output voltage v out1 (v) output curren i out (ma) 100 0.1 r1280d002c 8.5 9 9.5 10 10.5 11 11.5 0 0.01 0.02 0.03 0.04 0.05 time (sec) output voltage v out1 (v) output current i out (ma) 100 0.1 20) load transient response (inverting side) vin=3.3v l2=6.8 h l2=6.8 h r1280d002a -11.5 -11 -10.5 -10 -9.5 -9 0.000 0 0.000 1 0.000 2 0.000 3 0.000 4 0.000 5 0.000 6 time (sec) output voltage v out2 (v) output current i out (ma) -50 -0.1 r1280d002a -12 -11.5 -11 -10.5 -10 -9.5 0.000 0.005 0.010 0.015 0.020 time (sec) output voltage v out2 (v) output current i out (ma) -50 -0.1
rev.1.10 - 22 - l2=6.8 h l2=6.8 h r1280d002b -11.5 -11 -10.5 -10 -9.5 -9 0.000 0 0.000 1 0.000 2 0.000 3 0.000 4 0.000 5 0.000 6 time (sec) output voltage v out2 (v) output current i out (ma) -50 -0.1 r1280d002b -12 -11.5 -11 -10.5 -10 -9.5 0.000 0.005 0.010 0.015 0.020 time (sec) output voltage v out2 (v) output current i out (ma) -50 -0.1 l2=22 h l2=22 h r1280d002c -11.5 -11 -10.5 -10 -9.5 -9 0.0000 0.0001 0.0002 0.0003 0.0004 0.0005 0.0006 time(s) output voltage v out2 (v) output current i out (ma) -50 -0.1 r1280d002c -12 -11.5 -11 -10.5 -10 -9.5 0.000 0.005 0.010 0.015 0.020 time(s) output voltage v out2 (v) output current i out (ma) -50 -0.1
rev. 1.10 - 23 - typical application and technical notes r1280d002a/c c7 r6 l1 nmos ext1 ext2 v in gnd ampout 1 v refout dtc1 dtc2 v fb1 v fb2 r1 r2 c1 pmos c8 r3 r4 c3 l2 c2 c9 c4 r11 r10 c6 v out1 v out2 r7 r8 r5 c5 r9 diode external components inductor l1,2: 6.8 h, ldr655312t(tdk) for a type, 22 h for c type diode: fs1j3 (origin electronics) nmos: ir7601 (international rectifier) pmos: si3443 (siliconix) resistors: r1, r2, r3, r4 for setting output voltage. recommendation values are r1+r2 100k ? or r3+r4 100k ? r5=43k ? , r6=10k ? , r7=r9=22k ? , r8=r10=43k ? , r11=220k ? capacitors: ceramic capacitor (example) r1280d002a: c1=c2=10 f, c3=4.7 f, c4=0.22 f, c5=0.47 f, c6=120pf, c7=50pf, c8=1 f, c9=1000pf r1280d002c: c1=c2=10 f, c3=4.7 f, c4=0.22 f, c5=0.47 f, c6=220pf, c7=330pf, c8=1 f, c9=1000pf note: maximum voltage tolerance of each component should be considered. with the transistor shown above is appropriate to set up to 15v as output voltage. r1280d002b l1 c7 r6 l1 nmos ext1 ext2 v in gnd ce dtc1dtc2 v fb1 v fb2 r1 r2 c1 pmos c8 r3 r4 c3 l2 c4 c6 v out1 c5 diode r5
rev.1.10 - 24 - external components inductor l1,2: 6.8 h, ldr655312t(tdk) diode: fs1j3 (origin electronics) nmos: ir7601 (international rectifier) pmos: si3443 (siliconix) resistors: r1, r2, r3, r4 for setting output voltage. recommendation values are r1+r2 100k ? or r3+r4 100k ? r5=43k ? , r6=10k ? capacitors: ceramic capacitor (example) c1=c2=10 f, c3=4.7 f, c4=0.33 f, c5=0.33 f, c6=120pf, c7=50pf, c8=1 f note: maximum voltage tolerance of each component should be considered. with the transistor shown above is appropriate to set up to 15v as output voltage. application example r1280d002a/c l1 nmos ext1 ext2 gnd v in a mpout1 vrefout dtc1 dtc2 v fb1 v fb2 r1 r2 c1 pmos c8 r3 r4 c3 l2 c2 c9 c4 r11 r10 c6 vout1 vout2 r7 r8 r5 c5 r9 diode vout3 c10 c11 c7 r6 external components inductor l1,2: 6.8 h, ldr655312t(tdk) for a version, 22 h for r1280d002c diode: fs1j3 (origin electronics) nmos: ir7601 (international rectifier) pmos: si3443 (siliconix) resistors: r1, r2, r3, r4 for setting output voltage. recommendation values are r1+r2 100k ? or r3+r4 100k ? r5=43k ? , r6=10k ? , r7=r9=22k ? , r8=r10=43k ? , r11=220k ? capacitors: ceramic capacitor (example) r1280d002a: c1=c2=10 f, c3=4.7 f, c4=0.22 f, 5=0.47 f,c6=120pf,c7=50pf,c8=c10=c11=1 f,c9=1000pf r1280d002c:c1=c2=10 f, c 3 =4 . 7 f, c4=0.22 f, c 5 =0 . 4 7 f,c6=220pf,c7=330pf,c8=c10=c11=1 f,c9=1000pf this ic can be used 3 output tft bias circuit as shown above. v out3 =2 v out1 -vf note: maximum voltage tolerance of each component should be considered. with the transistor shown above is appropriate to set up to +15v as v out1 , -15v as v out2, 30v as v out3.
rev. 1.10 - 25 - r1280d002b c7 r6 l1 nmos ext1 ext2 gnd v in ce vrefout dtc1dtc2 v fb1 v fb2 r1 r2 c1 pmos c8 r3 r4 c3 l2 c4 c6 vout1 vout2 c5 diode r5 vout3 c10 c11 external components inductor l1,2: 6.8 h, ldr655312t(tdk) diode: fs1j3 (origin electronics) nmos: ir7601 (international rectifier) pmos: si3443 (siliconix) resistors: r1, r2, r3, r4 for setting output voltage. recommendation values are r1+r2 100k ? or r3+r4 100k ? r5=43k ? , r6=10k ? capacitors: ceramic capacitor (example) r1280d002b: c1=c2=10 f, c3=4.7 f, c4=0.33 f, 5=0.33 f, c6=120pf,c7=50pf,c8=c10=c11=1 f this ic can be used 3 output tft bias circuit as shown above. v out3 =2 v out1 -vf note: maximum voltage tolerance of each component should be considered. with the transistor shown above is appropriate to set up to +15v as v out1 , -15v as v out2, 30v as v out3 external components 1. how to set the output voltages as for step-up side, feedback (v fb1 ) pin voltage is controlled to maintain 1v, therefore, v out1 : r1+r2=v fb1 : r2 thus, v out1 =v fb1 (r1+r2)/r2 output voltage is adjustable with r1 and r2. as for inverting side, feedback (vfb2) pin voltage is controlled to maintain 0v, therefore, vrefout : r3=|-v out2 |:r4 thus, |-v out2 |=vrefout r4/r3 output voltage is adjustable with r3 and r4. 2. how to set soft starting time as for r1280d002b, soft start time is adjustable with connecting a capacitor to dtc pin. soft starting time, t ss1 and t ss2 are adjustable. soft starting time can be set with the time constant of rc. soft starting time can be described as in next formula. (topt=25 c) t ss1 ? rs1 c4, t ss2 ? rs2 c5 in the above formulas, rs1 value is typ. 32k ? , while rs2 value is typ. 45k ? . tolerance of these values is 25% caused by dispersion of wafer process parameters. on the other hand, as for r1280d002a/c, each soft start time is set with the time constant of each external resistor
rev.1.10 - 26 - and capacitor. technical notes on external components external components should be set as close to this ic as possible. especially, wiring of the capacitor connected to v in pin should be shortest. enforce the ground wire. large current caused by switching operation flows through gnd pin. if the impedance of ground wire is high, internal voltage level of this ic might fluctuate and operation could be unstable. recommended capacitance value of c3 is equal or more than 4.7 f. recommended maximum voltage tolerance of c3 is three times as large as set output voltage or more, because the external transistor might generate hi voltage with a shape of spike because of an effect from inductor. if the spike noise of v out is too large, the noise is feedback from v fb1 pin and operation might be unstable. in that case, use the resistor ranging from 10k ? to 50k ? as r5 and try to reduce the noise level. in the case of v out2 , use the resistor as much as 10k ? as r6. select an inductor with low d.c. current, large permissible current, and uneasy to cause magnetic saturation. if the inductance value is too small, i lx might be beyond the absolute maximum rating at the maximum load. select a schottky diode with fast switching speed and large enough permissible current. recommended capacitance value of c1 and c2 is as much as ceramic 10 f. in case that the operation with the system of dc/dc converter would be unstable, use tantalum capacitors with higher esr than ceramic capacitor. use a capacitor with three times as large as voltage tolerance of the capacitor. in this ic, for the test efficiency, latch release function is included. by forcing (v in -0.3) v or more voltage to dtc1 pin or dtc2 pin, latch release function works. consider the threshold voltage of power mosfet transistor. select an appropriate mosfet transistor, depending on the input voltage in order to make the mosfet turn on completely. performance of the power controller with using this ic depends on external components. each component, layout should not be beyond each absolute maximum rating such as voltage, current, and power dissipation.

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