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r1234d series pwm/vfm step-down dc/dc converte r with synchronous rectifier no.ea-137-070221 1 outline the r1234d series are cmos-based pwm step-down dc/ dc converters with synchronous rectifier, low supply current. each of these ics consists of an oscillator, a pwm cont rol circuit, a reference voltage unit, an error amplifier, a soft-start circuit, protection circuits, a protection against miss operation under low voltage (uvlo), pwm/vfm alternative circuit, a chip enable circuit, and a driver tr ansistor. a low ripple, high efficiency step-down dc/dc converter can be easily composed of this ic with only a few kinds of external components, or an inductor and capacitors. (as for r1234d001c/d types, di vider resistors are also necessary.) in terms of output voltage, it is fixed internally in the r1234dxx1a/b types. while in the r1234d001c/d types, output voltage is adjustable with external divider resistors. pwm/vfm alternative circuit is active with mode pin of the r1234d series. thus, when the load current is small, the operation can be switching into the vfm oper ation from pwm operation by the logic of mode pin and the efficiency at small load current can be improved. as protection circuits, current limit circuit which limits peak current of lx at each clock cycle, and latch type protection circuit which wo rks if the term of over-current condition keeps on a certain time in pwm mode exist. latch-type protection circuit works to latch an internal driver with keeping it disable. to releas e the condition of protection, after disable this ic with a chip enable circuit, enable it again, or restart this ic with power-on or ma ke the supply voltage at uvlo detector threshold level or lower than uvlo. features ? supply current ..................................................typ. 230 a (r1234dxx1a/c) typ. 250 a (r1234dxx1b/d) ? standby current ................................................typ. 0 a ? input voltage ran ge ........................................ 2.4v to 5.5v (abso lute maximum : 6.5v) ? output voltage rang e.......................................2.2v to 3.3v (r1234dxx1a/b) 0.8v to v in (r1234dxx1c/d) ? output voltage accuracy................................... 2.0% (r1234dxxa/b) ? oscillator frequen cy .........................................typ. 500khz (r1234dxx1a/c) typ. 800khz (r1234dxx1b/d) ? built-in driver on resistance ...........................pch 0.4 ? ,nch 0.6 ? (v in = 3v) ? control mode switch .........................................mode pin = ?l?: pwn mode pin = ?h?: vfm ? efficiency...........................................................typ. 90% ? package ............................................................ son-8 ? built-in soft-start fu nction.................................typ. 1.5ms ? latch-type protection fu nction .........................typ. 1.5ms ? built-in current limit circuit applications ? power source for portable equipment.
r1234d 2 block diagram r1234dxx1a/b v in lx v out osc vref ce chip enable soft start current protection output control uvlo phase comp. ?h? active mode pgnd v dd ?l? pwm ce 1 8 2 7 4 5 6 3 ?h? vfm pwm/vfm control agnd r1234dxx1c/d v in lx v fb osc vref ce chip enable soft start current limit output control uvlo phase comp. ?h? active mode pgnd v dd ?l? pwm 1 8 2 7 4 5 6 3 ?h? vfm pwm/vfm control agnd
r1234d 3 selection guide in the r1234d series, the output voltage, the osc illator frequency, and the taping type for the ics can be selected at the user's request. the selection can be made with designating the part number as shown below; r1234dxx 1x-xx -x part number a b c d e f code contents a designation of package type; d: son-8 b setting output voltage (v out ): stepwise setting with a step of 0.1v in the range of 1.2v to 3.3v is possible for a/b version."00" is for output voltage adjustable c/d version (0.8v to ) c 1: fixed d designation of optional function a: 500khz, fixed output voltage b: 800khz, fixed output voltage c: 500khz, adjustable output voltage d: 800khz, adjustable output voltage e designation of taping type; (refer to taping specification)"tr" is prescribed as a standard. f designation of composition of pin plating -f: lead free plating
r1234d 4 pin configuratio ? son-8 8 7 6 5 1 2 3 4 5678 4321 ? ? ? bottom view top view pin description pin no symbol pin description 1 v in voltage supply pin 2 pgnd power ground pin 3 v dd voltage supply pin 4 ce chip enable pin (active with "h") 5 v out /v fb output/feedback pin 6 mode mode changer pin ("l" = pwm, "h" = vfm) 7 agnd analogue ground pin 8 l x l x pin (cmos) * tab in the parts have gnd level. (they ar e connected to the reverse side of this ic.) do not connect to other wires or land patterns. absolute maximum ratings symbol item rating unit v in v in supply voltage 6.5 v v dd v dd pin voltage 6.5 v v lx l x pin voltage ? 0.3 to v in + 0.3 v v ce ce pin input voltage ? 0.3 to v in + 0.3 v v mode mode pin input voltage ? 0.3 to v in + 0.3 v v fb v fb pin input voltage ? 0.3 to v in + 0.3 v i lx l x pin output current ? 0.8 a p d power dissipation (son-8) 480 mw topt operating temperature range ? 40 to + 85 c tstg storage temperature range ? 55 to + 125 c * ) for power dissipation, please refer to package information to be described.
r1234d 5 electrical characteristics ? r1234dxxxa topt = 25 c symbol item conditions min. typ. max. unit v in operating input voltage 2.4 5.5 v v out step-down output voltage v in = v ce = v set + 1.5v, v mode = 0v, i out = 10ma typ. 0.98 v set typ. 1.02 v ? v out / ? topt step-down output voltage temperature coefficient ? 40 c < = < = c 150 ppm/ c fosc oscillator frequency v in = v ce = v set + 1.5v 425 500 575 khz i dd supply current v in = v ce = v set + 1.5v, v out = v mode = 0v 230 300 a istandby standby current v in = 5.5v, v ce = v out = 0v 0 5 a r onp on resistance of pch transistor v in = 5.0v 0.2 0.4 0.9 ? r onn on resistance of nch transistor v in = 5.0v 0.2 0.6 0.9 ? i lxleak l x leakage current v in = 5.5v, v ce = 0v, v lx = 0v or 5.5v ? 5.0 0.0 5.0 a i voutleak v out leakage current v in = 5.5v, v ce = 0v, v lx = 0v or 5.5v ? 0.1 0.0 0.1 a i ce ce input current v in = 5.5v, v mode = 0v, v ce = 5.5v or 0v ? 0.1 0.0 0.1 a i mode mode pin input current v in = 5.5v, v ce = 0v, v mode = 5.5v or 0v ? 0.1 0.1 a v ceh ce "h" input voltage v in = 5.5v, v out = 0v 1.5 v v cel ce "l" input voltage v in = 2.4v, v out = 0v 0.3 v v modeh mode "h" input voltage v in = v ce = 5.5v, v out = 0v 1.5 v v model mode "l" input voltage v in = v ce = 2.4v, v out = 0v 0.3 v maxduty oscillator maximum duty cycle v mode = 0v 100 % tstart delay time by soft-start function at no load, v in = v ce = v set + 1.5v 0.5 1.5 2.5 ms v lxlim l x limit voltage v mode = v out = 0v, v in = v ce = 3.0v v in ? 0.15 v in ? 0.35 v in ? 0.65 v tprot delay time for protection circuit v in = v ce = v set + 1.5v, v mode = 0v 0.5 1.5 2.5 ms v uvlo1 uvlo threshold voltage v in = v ce = 2.5v 1.5v, v out = 0v 1.8 2.1 2.2 v v uvlo2 uvlo released voltage v in = v ce = 1.5v 2.5v, v out = 0v 1.9 2.2 2.3 v vfmduty vfm duty cycle v in = v ce = v mode = 2.4v, v out = 0v 55 65 85 %
r1234d 6 ? r1234dxxxb topt = 25 c symbol item conditions min. typ. max. unit v in operating input voltage 2.4 5.5 v v out step-down output voltage v in = v ce = v set + 1.5v, v mode = 0v, i out = 10ma typ. 0.98 v set typ. 1.02 v ? v out / ? topt step-down output voltage temperature coefficient ? 40 c < = < = c 150 ppm/ c fosc oscillator frequency v in = v ce = v set + 1.5v 680 800 920 khz i dd supply current v in = v ce = v set + 1.5v, v out = v mode = 0v 250 450 a istandby standby current v in = 5.5v, v ce = v out = 0v 0 5 a r onp on resistance of pch transistor v in = 5.0v 0.2 0.4 0.9 ? r onn on resistance of nch transistor v in = 5.0v 0.2 0.6 0.9 ? i lxleak l x leakage current v in = 5.5v, v ce = 0v, v lx = 0v or 5.5v ? 5.0 0.0 5.0 a i voutleak v out leakage current v in = 5.5v, v ce = 0v, v lx = 0v or 5.5v ? 0.1 0.0 0.1 a i ce ce input current v in = 5.5v, v mode = 0v, v ce = 5.5v or 0v ? 0.1 0.0 0.1 a i mode mode pin input current v in = 5.5v, v ce = 0v, v mode = 5.5v or 0v ? 0.1 0.1 a v ceh ce "h" input voltage v in = 5.5v, v out = 0v 1.5 v v cel ce "l" input voltage v in = 2.4v, v out = 0v 0.3 v v modeh mode "h" input voltage v in = v ce = 5.5v, v out = 0v 1.5 v v model mode "l" input voltage v in = v ce = 2.4v, v out = 0v 0.3 v maxduty oscillator maximum duty cycle v mode = 0v 100 % tstart delay time by soft-start function at no load, v in = v ce = v set + 1.5v 0.5 1.5 2.5 ms v lxlim l x limit voltage v mode = v out = 0v, v in = v ce = 3.0v v in ? 0.15 v in ? 0.35 v in ? 0.65 v tprot delay time for protection circuit v in = v ce = v set + 1.5v, v mode = 0v 0.5 1.5 2.5 ms v uvlo1 uvlo threshold voltage v in = v ce = 2.5v 1.5v, v out = 0v 1.8 2.1 2.2 v v uvlo2 uvlo released voltage v in = v ce = 1.5v 2.5v, v out = 0v 1.9 2.2 2.3 v vfmduty vfm duty cycle v in = v ce = v mode = 2.4v, v out = 0v 55 65 85 %
r1234d 7 ? r1234dxxxc topt = 25 c symbol item conditions min. typ. max. unit v in operating input voltage 2.7 5.5 v v fb feedback voltage v in = v ce = v set + 1.5v, v mode = 0v, i out = 10ma 0.776 0.800 0.824 v ? v fb / ? topt feedback voltage temperature coefficient ? 40 c < = < = c 300 ppm/ c fosc oscillator frequency v in = v ce = v set + 1.5v 425 500 575 khz i dd supply current v in = v ce = v set + 1.5v, v fb = v mode = 0v 230 300 a istandby standby current v in = 5.5v, v ce = v fb = 0v 0 5 a r onp on resistance of pch transistor v in = 5.0v 0.2 0.4 0.9 ? r onn on resistance of nch transistor v in = 5.0v 0.2 0.6 0.9 ? i lxleak l x leakage current v in = 5.5v, v ce = 0v, v lx = 0v or 5.5v ? 5.0 0.0 5.0 a i vfbleak v fb leakage current v in = 5.5v, v ce = 0v, v fb = 0v or 5.5v ? 0.1 0.0 0.1 a i ce ce input current v in = 5.5v, v mode = 0v, v ce = 5.5v or 0v ? 0.1 0.0 0.1 a i mode mode pin input current v in = 5.5v, v ce = 0v, v mode = 5.5v or 0v ? 0.1 0.1 a v ceh ce "h" input voltage v in = 5.5v, v fb = 0v 1.5 v v cel ce "l" input voltage v in = 2.4v, v fb = 0v 0.3 v v modeh mode "h" input voltage v in = v ce = 5.5v, v fb = 0v 1.5 v v model mode "l" input voltage v in = v ce = 2.4v, v fb = 0v 0.3 v maxduty oscillator maximum duty cycle v mode = 0v 100 % tstart l x limit voltage at no load, v in = v ce = v set + 1.5v 0.5 1.5 2.5 ms v lxlim delay time by soft-start function v mode = v fb = 0v, v in = v ce = 3.0v v in ? 0.15 v in ? 0.35 v in ? 0.65 v tprot delay time for protection circuit v in = v ce = 3.6v, v mode = 0v 0.5 1.5 2.5 ms v uvlo1 uvlo threshold voltage v in = v ce = 2.5v 1.5v, v mode = 0v 1.95 2.20 2.45 v v uvlo2 uvlo released voltage v in = v ce = 1.5v 2.7v, v fb = 0v 2.20 2.40 2.65 v vfmduty vfm duty cycle v in = v ce = v mode = 2.4v, v fb = 0v 55 65 85 %
r1234d 8 ? r1234dxxxd topt = 25 c symbol item conditions min. typ. max. unit v in operating input voltage 2.7 5.5 v v fb feedback voltage v in = v ce = v set + 1.5v, v mode = 0v, i out = 10ma 0.776 0.800 0.824 v ? v fb / ? topt feedback voltage temperature coefficient ? 40 c < = < = c 300 ppm/ c fosc oscillator frequency v in = v ce = v set + 1.5v 680 800 920 khz i dd supply current v in = v ce = v set + 1.5v, v fb = v mode = 0v 250 400 a istandby standby current v in = 5.5v, v ce = v fb = 0v 0 5 a r onp on resistance of pch transistor v in = 5.0v 0.2 0.4 0.9 ? r onn on resistance of nch transistor v in = 5.0v 0.2 0.6 0.9 ? i lxleak l x leakage current v in = 5.5v, v ce = 0v, v lx = 0v or 5.5v ? 5.0 0.0 5.0 a i vfbleak v fb leakage current v in = 5.5v, v ce = 0v, v fb = 0v or 5.5v ? 0.1 0.0 0.1 a i ce ce input current v in = 5.5v, v mode = 0v, v ce = 5.5v or 0v ? 0.1 0.0 0.1 a i mode mode pin input current v in = 5.5v, v ce = 0v, v mode = 5.5v or 0v ? 0.1 0.1 a v ceh ce "h" input voltage v in = 5.5v, v fb = 0v 1.5 v v cel ce "l" input voltage v in = 2.4v, v fb = 0v 0.3 v v modeh mode "h" input voltage v in = v ce = 5.5v, v fb = 0v 1.5 v v model mode "l" input voltage v in = v ce = 2.4v, v fb = 0v 0.3 v maxduty oscillator maximum duty cycle v mode = 0v 100 % tstart l x limit voltage at no load, v in = v ce = v set + 1.5v 0.5 1.5 2.5 ms v lxlim delay time by soft-start function v mode = v fb = 0v, v in = v ce = 3.0v v in ? 0.15 v in ? 0.35 v in ? 0.65 v tprot delay time for protection circuit v in = v ce = 3.6v, v mode = 0v 0.5 1.5 2.5 ms v uvlo1 uvlo threshold voltage v in = v ce = 2.5v 1.5v, v mode = 0v 1.95 2.20 2.45 v v uvlo2 uvlo released voltage v in = v ce = 1.5v 2.7v, v fb = 0v 2.20 2.40 2.65 v vfmduty vfm duty cycle v in = v ce = v mode = 2.4v, v fb = 0v 55 65 85 %
r1234d 9 test circuits a l x v in ce v out mode v dd a gnd pgnd 1 3 7 2 8 4 5 6 r1234d series oscilloscope l x v in ce v out mode v dd a gnd pgnd 1 3 7 2 8 4 5 6 r1234d series test circuit for input current and leakage current test circuit for input voltage and uvlo voltage oscilloscope l v out 10 f l x v in ce v out mode v dd a gnd pgnd 1 3 7 2 8 4 5 6 r1234d series test circuit for output voltage, oscillator frequency, soft-starting time a l x v in ce v out mode v dd a gnd pgnd 1 3 7 2 8 4 5 6 r1234d series oscilloscope a l x v in ce v out mode v dd a gnd pgnd 1 3 7 2 8 4 5 6 r1234d series test circuit for supply current and standby current test circuit for on resistance of l x , limit voltage, delay time of protection circuit the bypass capacitor between power supply and gnd is a ceramic capacitor 10 f.
r1234d 10 typical application and technical notes 1) fixed output voltage type l v out c in c out load l x v in ce v out mode v dd agnd pgnd 1 2 3 4 8 7 6 5 c in 10 f c3216jb0j106m (tdk) c out 10 f ecstojx106r (panasonic) l 10 h lqh3c100k54 (murata) 2) adjustable output voltage type l v out c in c out cb r1 r2 load rb l x v in ce v out mode v dd agnd pgnd 1 2 3 4 8 7 6 5 c in 10 f c3216jb0j106m (tdk) c out 10 f ecstojx106r (panasonic) l 10 h lqh3c100k54 (murata) vfm mode may work with a parasitic diode, but we recommend that vfm mode used with an external diode in between l x and gnd. as for pwm mode, an external diode is not necessary. as for how to choose cb, rb, r1, and r2 values, refer to the technical notes.
r1234d 11 when you use these ics, consider the following issues; ? input same voltage into the power supply pins, v in and v dd . set the same level as agnd and pgnd. ? when you control the ce pin and mode pin by another power supply, do not make its "h" level more than the voltage level of v in /v dd pin. ? set external components such as an inductor, c in , c out as close as possible to the ic, in particular, minimize the wiring to v in pin and pgnd pin. ? at stand by mode, (ce = "l"), the l x output is hi-z, or both p-channel transistor and n-channel transistor of l x pin turn off. ? use an external capacitor c out with a capacity of 10 f or more, and with good high frequency characteristics such as tantalum capacitors. ? at vfm mode, (mode = "h"), latch protection circuit does not operate. ? if the mode is switched over into pwm mode from vfm mode during the operation, change the mode at light load current. if the load current us large, output voltage may decline. ? reinforce the v in , pgnd, and v out lines sufficiently. large switching current may flow in these lines. if the impedance of v in and pgnd lines is too large, the internal volt age level in this ic may shift caused by the switching current, and the operation might be unstable. the performance of power source circuits using these ics extremely depends upon the peripheral circuits. pay attention in the selection of the peripheral circuits. in particular, design the peripheral circuits in a way that the values such as voltage, current, and power of eac h component, pcb patterns and the ic do not exceed their respected rated values.
r1234d 12 operation of step-down dc/dc converter and output current the step-down dc/dc converter charges energy in the inductor when l x transistor is on, and discharges the energy from the inductor when l x transistor is off and controls with less energy loss, so that a lower output voltage than the input voltage is obtained. the operation will be explained with reference to the following diagrams: pch tr l nch tr v in i1 v out cl i2 gnd t = ? step 1: p-channel tr. turns on and current il ( = i1) flows, and energy is charged into cl. at this moment, il increases from ilmin ( = 0) to reach ilmax in proportion to the on-time period (ton) of p-channel tr. ? step 2: when p-channel tr. turns off, sy nchronous rectifier n-cha nnel tr. turns on in order that l maintains il at ilmax, and current il ( = i2) flows. ? step 3: il ( = i2) decreases gradually and reaches il = ilmin = 0 after a time period of topen, and n-channel tr. turns off. provided that in the continuous mode, next cycle starts before il becomes to 0 because toff time is not enough. in this case, il value increases from this ilmin (>0). in the case of pwm control system, the output voltage is maintained by controlling the on-time period (ton), with the oscillator frequency (f osc) being maintained constant. ? discontinuous conduction mode and continuous conduction mode the maximum value (ilmax) and the minimum value (ilmin) of the current flowing through the inductor are the same as those when p-channel tr. turns on and off. the difference between ilmax and ilmin, which is represented by ? i; ? i = ilmax ? ilmin = v out topen/l = (v in ? v out ) ton/l ........................................................e quation 1 where, t = 1/fosc = ton + toff duty (%) = ton/t 100 = ton fosc 100 topen < = toff in equation 1, v out topen/l and (v in ? v out ) ton/l are respectively shown t he change of the current at on, and the change of the current at off. when the output current (i out ) is relatively small, topen < toff as illu strated in the above diagram. in this case, the energy is charged in the inductor during the time peri od of ton and is discharged in its entirely during the time period of toff, therefore ilmin becomes to zero (ilmin = 0). when i out is gradually increased, eventually, topen becomes to toff (topen = toff), and when i out is further increased, ilmin becomes larger than zero (ilmin>0). the former mode is referred to as the discontinuous mode and the latter mode is referred to as continuous mode.
r1234d 13 in the continuous mode, when equation 1 is solv ed for ton and assumed that the solution is tonc tonc = t v out /v in ............................................................................................................. equat ion 2 when ton r1234d 14 how to adjust output voltage and about phase compensation as for adjustable output type, feedback pin (v fb ) voltage is controlled to maintain 0.8v. output voltage, v out is as following equation; v out r1 + r2 = v fb :r2 v out = v fb (r1 + r2)/r2 thus, with changing the value of r1 and r2, out put voltage can be set in the specified range. in the dc/dc converter, with the load current and external components such as l and c, phase might be behind 180 degree. in this case, the phase margin of the system will be less and stability will be worse. to prevent this, phase margin should be secured with proceeding the phase. a pole is formed with external components l and c out . out lc 1/2 ~ fpole a zero (signal back to zero) is formed with r1 and cb. ? fzero ~ 1/(2 r1 cb) first, choose the appropriate value of r1, r2 and cb. set r1 + r2 value 100k ? or less. for example, if l = 10h, c out = 10f, the cut off frequency of the pole is approximately 16khz. to make the cut off frequency of the zero higher than 16khz, set r1 = 42k ? and cb = 100pf. if v out is set at 1.5v, r2 = 48k ? is appropriate. if a ceramic capacitor is desirable as c out in your application, nonetheless of the usage of both the fixed output voltage type and adjustable output type, add 0.2 ? or more resistance to compensate the esr. further, if a ceramic capacitor is desirable to use as c out without adding another resister to compensate the esr, phase should be back drastically. to make it, r2 value should be smaller compared to r1. as a result, the set output voltage may be large. for example, to make v out = 1.5v, constants are r1 = 42k ? , r2 = 48k ? , and cb = 100pf. if the ceramic capacitor is used, under the heavy load condition, oscillation may be result. on the other hand, if r2 = 12k ? and v out = 3.6v, phase back becomes also large, and even if the device is used with a heavy load, the operation will be stable. rb is effective for reducing the noise on v fb . however, it is not always necessary. if it is necessary, use a resistance as much as 30k ? as rb.
r1234d 15 external components 1.inductor select an inductor that peak current does not exceed ilmax. if larger current than allowable current flows, magnetic saturation occurs and makes transform efficiency be worse. supposed that the load current is at the same, the smaller value of l is used, the larger the ripple current is. provided that the allowable current is large in that ca se and dc current is small, therefore, for large output current, efficiency is better than using an induct or with a large value of l and vice versa. 2.capacitor as for c in , use a capacitor with low esr (equivalent series resistance) ceramic type of a capacity at least 10 f for stable operation. c out can reduce ripple of output voltage, therefore as much as 10 f ceramic type is recommended. 3.diode if vfm mode is chosen at light load, use a schottky diode with small v f . a diode with small v f makes the efficiency of the circuit improved. small reverse direction current, ir is an important factor, however, v f has more important priority than i r . timing chart ce pin voltage intemal opertional a mplifier output intemal soft-start set voltage output short intemal oscillator waveform lx pin output soft-start time stable delay time of protection output short the timing chart as shown above describes the waveforms starting from the ic is enabled with ce and latched with protection. during the soft-start time, until the level is rising up to the internal soft-start set voltage, the duty cycle of l x is gradually wider and wider to prevent the over-s hoot of the voltage. during the term, the output of amplifier is "h". after the output voltage reaches the se t output voltage, they are balanced well. herein, if the output pin would be short circuit, the output of amplif ier would become "h" again, and the condition would continue for 2.0ms (typ.), latch circ uit would work and the output of l x would be latched with "off". (output = "high-z") if the output short is released before the latch circuit wo rks (within 2ms after output shorted), the output of amplifier is balanced in the stable state again. once the ic is latched, to release the protection, inpu t "l" with ce pin, or make the supply voltage at uvlo level or less.
r1234d 16 typical characteristics 1) output voltage vs. output current r1234d181a r1234d181b 1.70 1.90 1.80 1.75 1.85 1 10 1000 100 output current i out ( ma ) output voltage v out (v) v in =3.3v pwm v in =3.3v vfm v in =5.0v vfm v in =5.0v pwm 1.70 1.90 1.80 1.75 1.85 1 10 1000 100 output current i out ( ma ) output voltage v out (v) v in =3.3v pwm v in =3.3v vfm v in =5.0v vfm v in =5.0v pwm 2) efficiency vs. output current r1234d181a r1234d181b 1 10 1000 100 output current i out ( ma ) efficiency (%) v in =3.3v pwm v in =3.3v vfm v in =5.0v vfm v in =5.0v pwm 0 100 50 30 70 90 80 40 20 10 60 0 100 50 30 70 90 80 40 20 10 60 1 10 1000 100 output current i out ( ma ) efficiency ( % ) v in =3.3v pwm v in =3.3v vfm v in =5.0v vfm v in =5.0v pwm 3) output waveform (c out =10 f, tantalum, pwm) r1234d181a r1234d181b -0.08 0.06 -0.02 -0.06 0.02 0 -0.04 0.04 04 10 7 39 6 2 18 5 time t( s) output ripple voltage(v) v in =5v, i out =200ma esr=400m ? -0.04 0.05 0.01 -0.03 0.03 0.02 -0.01 -0.02 0 0.04 04 10 7 39 6 2 18 5 time t( s) output ripple voltage(v) v in =5v, i out =10ma esr=400m ?
r1234d 17 r1234d181b r1234d181b -0.06 0.05 -0.01 -0.05 0.03 0.01 -0.03 0 -0.04 0.02 -0.02 0.04 04 10 7 39 6 2 18 5 time t( s) output ripple voltage(v) v in =5v, i out =200ma esr=400m ? -0.04 0.04 -0.01 -0.03 0.02 0.01 0 -0.02 0.03 04 10 7 39 6 2 18 5 time t( s) output ripple voltage(v) v in =5v, i out =200ma esr=200m ? 4) load transient response (v in =5.0v, pwm) r1234d181a r1234d181b 0 300 200 0 0.1 -0.1 100 0 80 120 40 160 time t ( s) output current i out ( ma ) output current output voltage v out (v) 0ma 100ma output voltage 0 300 200 100 0 0.1 -0.1 0 80 120 40 160 time t ( s) output current i out ( ma ) output voltage v out (v) 0ma 100ma output current output voltage r1234d181a r1234d181b 0 -0.2 300 200 100 0.1 -0.1 0 0 80 120 40 160 time t ( s) output current i out ( ma ) output voltage v out (v) 0ma 200ma output current output voltage 0 -0.2 300 200 100 0.1 -0.1 0 0 80 120 40 160 time t ( s) output current i out ( ma ) output voltage v out (v) 0ma 200ma output current output voltage
r1234d 18 r1234d181a r1234d181b 0 300 200 100 0.1 -0.1 0 0 400 600 200 800 time t ( s) output current i out ( ma ) output voltage v out (v) output current output voltage 100ma 2ma 0 300 200 100 0.1 -0.1 0 0 400 600 200 800 time t ( s) output current i out ( ma ) output voltage v out (v) output voltage output current 100ma 2ma r1234d181a r1234d181b 0 300 200 100 0.1 -0.1 0 02030 10 40 time t ( s) output current i out ( ma ) output voltage v out (v) 100ma 0ma output voltage output current 0 300 200 100 0 0.1 0.2 -0.1 02030 10 40 time t ( s) output current i out ( ma ) output voltage v out (v) 100ma 0ma output voltage output current r1234d181a r1234d181b 300 200 100 -0.1 0 0.1 0.2 0 0 400 600 200 800 time t ( s) output current i out ( ma ) output voltage v out (v) 200ma 2ma output voltage output current 300 200 100 0.2 -0.1 0 0.1 0 0 400 600 200 800 time t ( s) output current i out ( ma ) output voltage v out (v) 200ma 2ma output voltage output current
r1234d 19 r1234d181a r1234d181b -0.1 0 300 200 100 0.2 0.1 0 02030 10 40 time t ( s) output current i out ( ma ) output voltage v out (v) 200ma 0ma output voltage output current -0.1 0 300 200 100 0.2 0.1 0 02030 10 40 time t ( s) output current i out ( ma ) output voltage v out (v) 200ma 0ma output voltage output current 5) turn on speed with ce pin r1234d181a r1234d181b 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v cel (v) ce input voltage output voltage pwm, i out =0ma output voltage v out (v) 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v cel (v) pwm, i out =0ma output voltage v out (v) ce input voltage output voltage r1234d181a r1234d181b 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v cel (v) pwm, i out =50ma output voltage v out (v) ce input voltage output voltage 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v cel (v) pwm, i out =50ma output voltage v out (v) ce input voltage output voltage
r1234d 20 r1234d181a r1234d181b 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v cel (v) pwm, i out =200ma output voltage v out (v) ce input voltage output voltage 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v cel (v) pwm, i out =200ma output voltage v out (v) ce input voltage output voltage r1234d181a r1234d181b 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v ceh (v) vfm, i out =0ma output voltage v out (v) ce input voltage output voltage 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v ceh (v) vfm, i out =0ma output voltage v out (v) ce input voltage output voltage r1234d181a r1234d181b 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v ceh (v) vfm, i out =50ma output voltage v out (v) ce input voltage output voltage 2 1 0 4 2 0 2.8 0.4 1.6 2.4 0.8 0 1.2 2.0 time t( s) ce input voltage v ceh (v) vfm, i out =50ma output voltage v out (v) ce input voltage output voltage
r1234d 21 6) output ripple voltage vs. output current 7) output voltage vs. temperature r1234d181b r1234d181b 0 80 50 30 60 70 10 40 20 50 450 100 250 400 150 500 200 350 300 output current i out (m a ) v in =5.0v v in =3.3v c out =10 f, tantalum, esr=400m ? output ripple voltage( m v) 1.70 1.90 1.80 1.85 1.75 -40 -25 50 75 085 25 temperature topt( c) i out =100m a output voltage v out (v) 8) output voltage vs. input voltage 9) frequency vs. temperature r1234d181b 1.60 2.00 1.80 1.90 1.65 1.70 1.85 1.95 1.75 234 6 5 input voltage v in ( v ) i out =20m a output voltage v out (v) 300 1000 600 800 400 700 900 500 temperature topt( c) v in =v out +1.5v frequency f (khz) 800khz 500khz -40 -25 50 75 085 25 10) supply current vs. temperature 11) soft-start time vs. temperature r1234d181b 100 450 250 350 150 300 400 200 temperature topt( c) v in =5.5v supply current i dd ( a) 800khz 500khz -40 -25 50 75 085 25 0 3.0 1.5 2.5 0.5 2.0 1.0 temperature topt( c) soft-start time tstart ( ms ) 800khz 500khz -40 -25 50 75 085 25 v in =3.3v
r1234d 22 12) uvlo threshold vs. temperature 13) ce input voltage vs. temperature 1.8 2.3 2.1 1.9 2.2 2.0 temperature topt( c) uvlo voltage ( v ) -40 -25 50 75 085 25 uvlo threshold voltage uvlo released voltage 0 1.6 0.8 0.2 1.2 0.4 1.0 1.4 0.6 temperature topt( c) ce input voltage v ce ( v ) ce input voltage( v ) "l" ce input voltage( v ) "h" -40 -25 50 75 085 25 14) mode input voltage vs. temperature 15) maximum duty cycle at vfm mode vs. temperature 0 1.6 0.8 0.2 1.2 0.4 1.0 1.4 0.6 temperature topt( c) mode input voltage v mode ( v ) mode input voltage "l" mode input voltage "h" -40 -25 50 75 085 25 50 80 70 55 60 75 65 temperature topt( c) vfm duty cycle vfmduty ( % ) -40 -25 50 75 085 25 16) lx transistor on resistance vs. temperature 17) lx limit voltage vs. temperature 0 1.00 0.25 0.50 0.75 temperature topt( c) on resistance r on ( ? ) nchtr pchtr -40 -25 50 75 085 25 0.10 0.40 0.30 0.15 0.20 0.35 0.25 temperature topt( c) lx limit voltage v lxlim ( v ) -40 -25 50 75 085 25
r1234d 23 18) protection delay time vs. temperature 0 3.0 2.4 0.6 1.2 1.8 temperature topt( c) protaction delay time tprot( ms ) -40 -25 50 75 085 25
package information pe-son-8-0611 ? son-8 unit: mm package dimensions 0.2 0.1 0.2 0.1 0.13 0.05 0.15 ? 0.15 + 0.1 0.15 ? 0.15 + 0.1 0.23 0.1 2.9 0.2 0.3 0.1 2.8 0.2 0.13 0.05 3.0 0.2 0.475typ. 0.9max. 85 14 0.1 0.65 0.1 m attention : tab suspension leads in the parts have v dd or gnd level. (they are connected to the reverse side of this ic.) refer to pin discription. do not connect to other wires or land patterns. bottom view taping specification ? 1.1 0.1 2.0 0.05 4.0 0.1 0.2 0.1 1.5 +0.1 0 3.3 4.0 0.1 2.0max. tr user direction of feed 3.5 0.05 8.0 0.3 1.75 0.1 3.2 taping reel dimensions reuse reel (eiaj-rrm-08bc) (1reel=3000pcs) 11.4 1.0 9.0 0.3 21 0.8 2 0.5 ? 60 0 ? 180 ? 1.5 +1 0 13 0.2 ?
package information pe-son-8-0611 power dissipation (son-8) this specification is at mounted on board. power dissipation (p d ) depends on conditions of mounting on board. this specification is based on the measurement at the condition below: measurement conditions standard land pattern environment mounting on board (wind velocity=0m/s) board material glass cloth epoxy plactic (double sided) board dimensions 40mm 40mm 1.6mm copper ratio top side : approx. 50% , back side : approx. 50% through-hole 0.5mm 44pcs measurement result (topt=25 c,tjmax=125 c) standard land pattern free air power dissipation 480mw 300mw thermal resistance ja = (125 ? 25 c)/0.48w = 208 c/w 333 c/w 0 50 100 25 75 85 125 150 ambient temperature ( c) 0 200 100 300 400 480 500 600 power dissipation p d (mw) on board free air 40 40 power dissipation measurement board pattern ic mount area (unit : mm) recommended land pattern 0.65 0.65 1.15 0.35 (unit: mm)
mark information me-r1234d-0608 r1234d series mark specification ? son-8 r 1 2 3 4 5 6 1 to 4 : product code (refer to part number vs. product code) 5 , 6 : lot number ? part number vs. product code product code product code product code part number 1 2 3 4 part number 1 2 3 4 part number 1 2 3 4 r1234d121a h 1 2 a r1234d121b h 1 2 b r1234d001c h 0 1 c r1234d131a h 1 3 a r1234d131b h 1 3 b r1234d001d h 0 1 d r1234d141a h 1 4 a r1234d141b h 1 4 b r1234d151a h 1 5 a r1234d151b h 1 5 b r1234d161a h 1 6 a r1234d161b h 1 6 b r1234d171a h 1 7 a r1234d171b h 1 7 b r1234d181a h 1 8 a r1234d181b h 1 8 b r1234d191a h 1 9 a r1234d191b h 1 9 b r1234d201a h 2 0 a r1234d201b h 2 0 b r1234d211a h 2 1 a r1234d211b h 2 1 b r1234d221a h 2 2 a r1234d221b h 2 2 b R1234D231A h 2 3 a r1234d231b h 2 3 b r1234d241a h 2 4 a r1234d241b h 2 4 b r1234d251a h 2 5 a r1234d251b h 2 5 b r1234d261a h 2 6 a r1234d261b h 2 6 b r1234d271a h 2 7 a r1234d271b h 2 7 b r1234d281a h 2 8 a r1234d281b h 2 8 b r1234d291a h 2 9 a r1234d291b h 2 9 b r1234d301a h 3 0 a r1234d301b h 3 0 b r1234d311a h 3 1 a r1234d311b h 3 1 b r1234d321a h 3 2 a r1234d321b h 3 2 b r1234d331a h 3 3 a r1234d331b h 3 3 b

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