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1/20 datashee t tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 14? 001 single-chip type with built -in fet switching regulators flexible step-down switching regulators with built-in power mosfet bd9673aefj general description output 1.5a and below high efficiency rate step-down switching regulator power mosfet internal type bd9673aefj mainly used as secondary side power supply, for example from fixed power supply of 12v, 24v etc, step-down output of 1.2v/1.8v/3.3v /5v, etc, can be produced. this ic has external coil/capacitor down-sizing through 300khz frequency operation, inside nch-fet sw for 45v ?withstand-pressure? commutation and also, high speed load response through current mode control is a simple external setting phase compensation system, through a wide range external constant, a compact power supply can be produced easily. features internal 200 m ? nch mosfet output current 1.5a oscillation frequency 300khz synchronizes to external clock ( 200khz 500khz ) feedback voltage 1.0v1.0% internal soft start function internal over current protect circuit, low input error prevention circuit, heat protect circuit on/off control through en pin (standby current 0 a typ.) package: htsop-j8 package key specifications input voltage ref. precision (ta=25 ) max output current operating temperature max junction temperature 7v to 42v 1.0% 1.5a (max.) -40 to 105 -55 to 150 packages htsop-j8 4.90mm x 6.00mm x 1.00mm a pplications for household machines in general that have 12v/24v lines, etc. typical application circuits structure silicon monolithic integrated circuit this product is not designed for normal operation with in a radioactive. figure 1. typical application circuit htsop-j8 vcc 24v vout c1 6800pf en l x gnd vc fb vcc bst en sync sync 10f/35v grm31eb3ya106ka12l (murata) 47f/15v grm32eb31c476ke15 (murata) rb056l-40 (rohm) 15h cdrh105r (sumida) 0.01f r3 10k ? r2 30k ? r1 120k ? on/off control 5v/1.0 a c2 open
2/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 pin configuration pin description pin no. pin name description 1 lx terminal for inductor 2 gnd ground pin 3 vc error amplifier output 4 fb inverting node of the trans conductance error amplifier 5 sync input pin of an external signal for t he device synchronized by external signal 6 en stand-by on/off pin 7 bst voltage supply pin for high side fet driver 8 vcc voltage input pin block diagram 1 234 8765 thermal pad figure 2. pin configuration (top view) figure 3. block diagram e 1.0v erro r vc l x reference uvlo vref reg 200m ? soft start on/of gn + - + f bs tsd shutdown 10? v r q s current com p arato r vou t syn oscillato r 300kh + - current sense amp
3/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 description of blocks 1. reference this block generates error amp standard voltage. standard voltage is 1.0v. 2. reg this is a gate drive voltage generator and 5v low saturation regulator for internal circuit power supply. 3. osc this is a precise wave oscillation circuit with oper ation frequency fixed to 300 khz fixed (self-running mode). to implement the synchronizat ion feature connect a square wave (hi level: hi gher than 2v low level: lower than 0.8v ) to the sync pin. the synchronization fr equency range is 200 khz to 500 khz. after connecting the rising edge of lx will be synchron ized to the falling edge of sync pin signal after 3 count. at the synchronization remove the ex ternal clock, the device transitions self-running mode after 7 microseconds. 4. soft start a circuit that does soft start to the output voltage of dc/dc comparator, and prevents rush current during start-up. soft start time is set at ic internal, after 10ms from starting-up en pin, standard voltage comes to 1.0v, and output voltage becomes set voltage. 5. error amp this is an error amplifier what detects ou tput signal, and outputs pwm control signal. internal standard voltage is set to 1.0v. also, c and r are connected between the output (vc) pin gnd of error amp as phase compensation elements. (see p.11) 6. icomp this is a voltage-pulse width converter that controls output voltage in response to input voltage. this compares the voltage added to the internal slope wa veform in response to the fet ws current with error amplifier output voltage, controls the widt h of output pulse and outputs to driver. 7. nch fet sw this is an internal commutation sw that converts coil current of dc/dc comparator. it contains 45v? with stand pressure? 200m ? sw. because the current rating of this fet is 2.0a incl uded ripple current, please use at within 2.0a. the device has the circuit of over current protec tion for protecting the fet from over current. to detect ocp 2 times sequentially, the device will stop and after 13 msec restart. 8. uvlo this is a low voltage error prevention circuit. this prevents internal circuit error during increase of power supply voltage and during decline of power supply voltage. it monitors vcc pin voltage and internal reg voltage, and when vcc voltage becomes 6.4v and below, it turns off all output fet and turns off dc/dc comparator output, and soft start circuit resets. now this threshold has hysteresis of 200mv. 9. tsd this is a heat protect (t emperature protect) circuit. when it detects an abnormal temperature exce eding maximum junction temperature (tj=150 ), it turns off all output fet, and turns off dc/dc comparator output. w hen temperature falls, it has/with hysteresis and automatically returns. 10. en with the voltage applied to en pin(6pin), ic on/off can be controlled. when a voltage of 2.0v or more is applied, it tu rns on, at open or 0v application, it turns off. about 550k ? pull-down resistance is contained within the pin.
4/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 absolute maximum ratings item symbol ratings unit vcc-gnd supply voltage vcc 45 v bst-gnd voltage vbst 50 v bst-lx voltage Svbst 7 v en-gnd voltage ven 45 v lx-gnd voltage vlx 45 v fb-gnd voltage vfb 7 v vc-gnd voltage vc 7 v sync-gnd voltage sync 7 v high-side fet drain current idh 3.5 a power dissipation pd 3.76 (*1) w operating temperature topr -40 +105 storage temperature tstg -55 +150 junction temperature tjmax +150 (*1)during mounting of 70701.6t mm 4layer boar d (copper area: 70mm70mm).reduce by 30.08mw for every 1 increase. (above 25 ) electrical characteristics ( unless otherwise specified ta = 2 5 , vcc=24v, vo=5v,en=3v ) parameter symbol limits unit conditions min. typ. max. circuit current stand-by current of vcc ist 0 10 a ven=0v circuit current of vcc icc 1 2 ma fb=1.2v under voltage lock out (uvlo) detect voltage vuv 6.1 6.4 6.7 v hysteresis width vuvhy 200 300 mv oscillator oscillating frequency fosc 270 300 330 khz max duty cycle dmax 85 91 97 % error amp fb threshold voltage vfb 0.990 1.000 1.010 v input bias current ifb -1.0 0 1.0 a vfb=0v error amplifier dc gain a vea 700 7000 70000 v/v trans conductance g ea 110 220 440 a/v ivc=10a, vc=1.5v soft start time tsoft 7 10 13 ms current sense amp vc to switch current transconductance g cs 5 10 20 a/v output lx nmos on resistance ronh 200 340 m lx pre-charge nmos on resistance ronl 10 17
5/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 over current detect current iocp 2 3.3 a ctl en pin control voltage on venon 2 vcc v off venoff -0.3 0.8 v en pin input current ren 2.7 5.5 11 a ven=3v sync sync pin control voltage high vsynch 2.0 5.5 v low vsyncl -0.3 0.8 v sync pin input current ren 6 12 24 a vsync=3v sync falling edge to lx rising edge delay tdelay 200 400 600 ns not designed to withstand radiation. operating ratings(ta=25 ) item symbol ratings unit min typ max power supply voltage vcc 7 42 v output voltage vout 1.0 (*2) vcc0.7 v (*2)restricted by minimu m on pulse typ. 200ns detailed description synchronizes to external clock the sync pin can be used to synchronize the regulator to an ex ternal system clock. to implement the synchronization feature connect a square wave to sync pin. the square wave amplitude must transition lower than 0.8v and higher than 2.0v on the sync pin and have an on time greater than 100ns and an off time greater than 100ns. the synchronization frequency range is 200 khz to 500 khz. the rising edge of the lx will be synchronized to the falling edge of sync pin signal after sync input pulse 3 count. at the synchronizati on, the external clock is removed, the device transitions self-running mode after 7 microseconds. sync sync_latch lx set the latch for synchronization 400nsec about 7sec figure 4. timing chart at synchronization
6/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 the case of not using the f unction of synchronization although the sync pin is pulled down by resistor in this devic e, if the function of the sync hronization is not used, it is recommended to connect sync pin to ground. soft start the soft start time of bd9673aefj is determined by the dcdc operating frequency (self-run mode 300 khz ?10ms). if synchronization is used at the time of en=on, the soft start time is restricted by sync pin input pulse frequency. sync pin input pulse frequency is fosc_ex khz, the soft start time is expressed by below equation. ocp operation the device has the circuit of over current protec tion for protecting the fet from over current. to detect ocp 2 times sequentially, the device will stop and after 13 msec restart. fosc_ex 300 tss = 10 [ms] figure 5. the method to disposal the sync pin without synchronization figure 6. timing chart at ocp operation vc lx vout ocp ocp_latch set the ocp latch by detecting the ocp current 2 times sequencially output connect to gnd ocp latch reset after 13 msec (300 hz 4000 counts) force the high side fet off by detecting ocp current (pulse by pulse protection) vc voltage discharged by ocp latch ocp threshold vc voltage rising by output connect to gnd
7/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 reference data (unless otherwise specified, ta=25 , vcc=24v, vo=5v, en=3v) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 -60 -40 -20 0 20 40 60 80 100 120 icc[ua] temp[ ] vcc=12v vcc=24v vcc=36 v vcc=42v 0 0.5 1 1.5 2 0 5 10 15 20 25 30 35 40 45 icc[ma] vcc[v] temp= \ 40 temp=25 temp=105 0 0.5 1 1.5 2 -60 -40 -20 0 20 40 60 80 100 120 icc[ma] temp[ ] vcc=42v vcc=36v vcc=24v vcc=12v 0 1 2 3 4 5 6 7 8 -60 -40 -20 0 20 40 60 80 100 120 uvlo ? threshold[v] temp[ ] reset ? voltage detect ? voltage 250 260 270 280 290 300 310 320 330 340 350 -60 -40 -20 0 20 40 60 80 100 120 frequency[khz] temp[ ] 0 10 20 30 40 50 60 70 80 90 100 -60 -40 -20 0 20 40 60 80 100 120 maxduty[%] temp[ ] figure 12. oscillation frequency temperature characteristics figure 11.. uvlo threshold temperature characteristics figure 13. max duty temperature characteristics figure 8. standby current temperature characteristics figure 10.. circuit current temperature characteristics figure 9. circuit current power supply voltage characteristics
8/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 0.990 ? 0.992 ? 0.994 ? 0.996 ? 0.998 ? 1.000 ? 1.002 ? 1.004 ? 1.006 ? 1.008 ? 1.010 ? -60 -40 -20 0 20 40 60 80 100 120 vfb ? threshold[v] temp[ ] vcc=12v vcc=24v vcc=42v vcc=36v 0.990 ? 0.992 ? 0.994 ? 0.996 ? 0.998 ? 1.000 ? 1.002 ? 1.004 ? 1.006 ? 1.008 ? 1.010 ? 0 5 10 15 20 25 30 35 40 45 vfb ? threshold[v] vcc[v] temp=105 temp=25 temp= \ 40 \ 60 \ 50 \ 40 \ 30 \ 20 \ 10 0 10 20 30 40 50 60 00.511.52 vc ? terminal ? current[ua] vfb[v] temp=105 temp=25 temp= \ 40 0 2 4 6 8 10 12 14 16 -60 -40 -20 0 20 40 60 80 100 120 soft ? start ? time[ms] temp[ ] vcc=42v vcc=36v vcc=24v vcc=12v 0 50 100 150 200 250 300 -60 -40 -20 0 20 40 60 80 100 120 highside ? fet ? ron ? [m ] temp[ ] 0 5 10 15 20 -60 -40 -20 0 20 40 60 80 100 120 precharge ? fet ? ron ? [ ] temp[ ] figure 15. fb threshold power supply characteristics figure 14. fb threshold voltage temperature characteristics figure 16. fb voltage - ivc current characteristics figure 17. soft start time temperature characteristics figure 18. nch fet on resistance temperature characteristics figure 19. pre-charge fet on resistance temperature characteristics
9/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 -60 -40 -20 0 20 40 60 80 100 120 vc ? to ? sw ? current ? transconductance[a/v] temp[ ] 0 0.5 1 1.5 2 -60 -40 -20 0 20 40 60 80 100 120 en ? threshold[v] temp[ ] figure 20. ocp detect current temperature characteristics figure21. vc to sw current transconductance temperature characteristics figure 22. en threshold temperature characteristics 0 1 2 3 4 5 6 -60 -40 -20 0 20 40 60 80 100 120 ocp_peak_current[a] temp[ ] vcc=12v vcc=24v vcc=36v vcc=42v
10/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 figure 23. reference application circuit figure 30. stop waveform figure 24. electric power conversion rate figure 26. frequency response characteristics (io=1.0a) figure 25. frequency response characteristics (io=0.5a) figure 29. startup waveform en 5v/div (dc) lx 10v/div (dc il 0.5a/div (dc) vout 2v./div (dc) en 5v/div (dc) lx 10v/div (dc il 0.5a/div (dc) vout 2v./div (dc) figure 27. load response characteristics (io=0a 1.5a) figure 28. load response characteristics (io=1.5a 0a) vout 200mv/div (ac) il 1a/div (dc) vout 200mv/div (ac) il 1a/div (dc) phase gain phase gain example of reference application circuit (input 24v, output 5.0v) reference application data (example of reference application circuit) vcc 24v vout c1 6800pf en lx gnd vc fb vcc bst en sync sync 10f/35v grm31eb3ya106ka12l (murata) 47f/15v grm32eb31c476ke15 (murata) rb056l-40 (rohm) 15h cdrh105r (sumida) 0.01f r3 10k ? r2 30k ? r1 120k ? on/off control 5v/1.0a c2 open 0 10 20 30 40 50 60 70 80 90 100 0 500 1000 1500 transformation ? efficiency ? [%] load ? current[ma] vcc=12v vcc=24v vcc=36v vcc=42v
11/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 figure 31. reference application circuit figure 32. electric power conversion rate figure 34. frequency response characteristics (io=1.0a) figure 33. frequency response characteristics (io=0.5a) example of reference application circuit (input 24v, output 12v) reference application data (example of reference application circuit) 0 10 20 30 40 50 60 70 80 90 100 0 500 1000 1500 transformation ? efficiency ? [%] load ? current[ma] vcc=7v vcc=12v vcc=24v vcc=42v
12/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 figure 35. reference application circuit figure 36. electric power conversion rate figure 38. frequency response characteristics (io=3.0a) figure 37. frequency response characteristics (io=0.5a) example of reference application circuit (input 24v, output 3.3v) reference application data (example of reference application circuit) 0 10 20 30 40 50 60 70 80 90 100 0 500 1000 1500 transformation ? efficiency ? [%] load ? current[ma] vcc=24v vcc=36v vcc=42v
13/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 figure 39. reference application circuit figure 40. electric power conversion rate figure 42. frequency response characteristics (io=3.0a) figure 41. frequency response characteristics (io=0.5a) 0 10 20 30 40 50 60 70 80 90 100 0 500 1000 transformation ? efficiency ? [%] load ? current[ma] vcc=24v vcc=12v example of reference application circuit (input 24v, output -12v) reference application data (example of reference application circuit)
14/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 evaluation board pattern (reference) layout is a critical portion of good powe r supply design. there are several signal s paths that conduct fast changing currents or voltages that can interact with stray inductance or parasi tic capacitance to generate noise or degrade the power supplies performance. to help eliminate these pr oblems, the vcc pin should be bypassed to ground with a low esr ceramic bypass capacitor with b dielectric. care should be taken to minimize the loop area formed by the bypass capacitor connections, the vcc pin, and the anode of the catch diode. see fig.28 for a pcb layout example. the gnd pin should be tied directly to the thermal pad under the ic and the thermal pad. the thermal pad should be connected to any internal pcb ground pl anes using multiple vias directly under the ic. the lx pin should be routed to the cathode of the ca tch diode and to the output inductor. since the lx connection is the switching node, the catch diode and output induct or should be located close to the lx pins, and the area of the pcb conductor minimized to prevent excessive capacitive coupling. for operat ion at full rated load, the top side ground area must provide adequate heat dissipating area. the additional external comp onents can be placed approximately as shown. it may be possible to obtain acceptable performance with alternate pcb layouts, however this layout has been shown to produce good results and is meant as a guideline. figure 43. evaluation board pattern figure 44. reference board pattern
15/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 power dissipation it is shown below reducing characteristics of power dissipation to mount 70mm70mm1.6mm t pcb junction temperature must be designed not to exceed 150 . power dissipation estimate the following formulas show how to estimate the device powe r dissipation under continuous mode operations. they should not be used if the device is working in the discontinuous conduction mode. the device power dissipation includes: 1) conduction loss pcon = iout 2 ronh vout/vcc 2) switching loss: psw = 1.25 10 ?9 vcc 2 iout fsw 3) gate charge loss pgc = 22.8 10 ?9 fsw 4) quiescent current loss pq = 1.0 10 ?3 vcc where: iout is the output current (a , ronh is the on-resistance of the high-side mosfet ? , vout is the output voltage (v). vcc is the input voltage (v), fsw is the switching frequency (hz). therefore power dissipation of ic is the sum of above dissipation. pd = pcon + psw + pgc + pq for given tj, tj =ta + ja pd where: pd is the total device power dissipation (w), ta is the ambient temperature ( ) tj is the junction temperature ( ), ja is the thermal resistance of the package ( ) application components selection method (1) inductor something of the shield type that fulfills the current rating (current value ipec ac below), with low dcr (direct current resistance element) is recommended. value of inductor influences inductor ripple curr ent and becomes the caus e of output ripple. in the same way as the formula below, this ripple current can be made small for as big as the l value of coil or as high as the switching frequency. figure 45. power dissipation ( 70mm 70mm 1.6mm t 1layer pcb) 0 500 1000 1500 2000 2500 3000 3500 4000 0 25 50 75 100 125 150 power dissipation - mw ambient temperature - 3760mw 2210mw 1100mw htsop-j8 package - on 70mm70mm1.6mm t glass epoxy pcb 1-layer board backside copper foil area 0mm0mm 2-layer board ( backside copper foil area 15mm15mm) 2-layer board backside copper foil area 70mm70mm 4-layer board backside copper foil area 70mm70mm 820mw
16/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15? 001 ipeak =iout + Sil/2 [a] (1) ( : efficiency, S il: output ripple current, f: switching frequency) for design value of inductor ripple current, pleas e carry out design tentatively with about 20% 50% of maximum input current. when current that exceeds coil rating flows to the coil, t he coil causes a magnetic saturation, and there are cases wherein a decline in efficiency, oscillation of output happens. please have sufficient margin and select so that peak current does not exceed rating current of coil. (2) output capacitor in order for capacitor to be used in output to reduce outp ut ripple, low ceramic capacitor of esr is recommended. also, for capacitor rating, on top of pu tting into consideration dc bias characteristics, please use something whose maximum rating has sufficient margin with respect to the output voltage. output ripple voltage is looked for using the following formula. please design in a way that it is held within capacity ripple voltage. (3) output voltage setting error amp internal standard voltage is 1.0v. output voltage is determined as seen in (4) formula. (4) bootstrap capacitor please connect from 0.01f (laminate ceramic capacitor) between bst pin and lx pins. i l figure 46. inductor current figure 47.voltage return resistance setting method vref 1.0v vout error amp r1 r2 fb S il= [a] (2) l vin-vout vin vout f 1 vpp= Sil S il r esr [v] ??? (3) 2 f co 1 vo= 1.0 [v] ??? (4) r2 (r1+r2)
17/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15 ? 001 vout v a gcsrladc fb ea = (5) schottky diode recommend selecting a diode which is satisfied with maximum input voltage of the applicat ion, and which is larger than maximum current rating. if vf of schott ky diode is large, there is a possibility that vf of internal parasitic diode and vf of schottky diode reverse and might cause ic error operat ion when increasing a difference in temperature with ic. recommend using a diode with smaller vf as possible, and location is recommended to be nearest to the pin. bd9673efj use below diode is recommended. ? v rm [v] i o [a] v f [v] i r [ma] rb050l-40 40 3 0.55 1 rb055l-30 30 3 0.55 3 (6) about adjustment of dc/dc co mparator frequency characteristics role of phase compensation element c1, c2, r3 (s ee p.7. example of reference application circuit) stability and responsiveness of loop are controlled thro ugh vc pin which is the output of error amp. the combination of zero and pole that determines stability and responsiveness is adjusted by the combination of resistor and capacitor that are connected in series to the vc pin. dc gain of voltage return loop can be calculated for using the following formula. here, vfb is feedback voltage (1.0v).a ea is voltage gain of error amplifier (typ: 77db), gcs is the trans-conductance of curr ent detect (typ: 10a/v), and rl is the output load resistance value. there are 2 important poles in the control loop of this dc/dc. the first occurs with/ through the output resistance of p hase compensation capacitor (c1) and error amplifier. the other one occurs with/through the output capacitor and load resistor. these poles appear in the frequency written below. here, g ea is the trans-conductance of error amplifier (typ: 220 a/v). here, in this control loop, one zero becomes important. wi th the zero which occurs because of phase compensation capacitor c1 and phase compensation re sistor r3, the frequency below appears. also, if output capacitor is big, and t hat esr (resr) is big, in this control loop, there are cases when it has an important, separate zero (esr zero). this esr zero occurs due to esr of output capaci tor and capacitance, and exists in the frequency below. (esr zero) in this case, the 3 rd pole determined with the 2 nd phase compensation capacitor (c2) and phase correction resistor (r3) is used in order to correct the esr zero results in loop gain. this pole exists in the frequency shown below. (pole that corrects esr zero) resr cout2 1 fz esr = r3c1 2 1 1 fz = r3c2 2 1 3 fp = g ea fp1 = 2c1a ea 1 fp2 = 2cout rl
18/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15 ? 001 the target of phase compensation design is to create a communication function in order to acquire necessary band and phase margin. cross-over frequency (band) at which loop gain of return loop becomes ?0? is important. when cross-over frequency becomes low, power supply fluctuation response, load response, etc worsens. on the other hand, when cross-over frequency is too high, instability of the loop can occur. tentatively, cross-over frequency is targeted to be made 1/20 or below of switching frequency. selection method of phase compensation constant is shown below. 1. phase compensation resistor (r3) is selected in order to set to the desired cross-over frequency. calculation of rc is done using the formula below. here, fc is the desired cross-over frequency. it is made about 1/20 and below of the no rmal switching frequency (fs). 2. phase compensation capacitor (c1) is select ed in order to achieve the desired phase margin. in an application that has a representati ve inductance value (about several h 20h), by matching zero of compensation to 1/4 and below of the cross-over frequency, sufficient phase margin can be acquired. c1 can be calculated using the following formula. rc is phase compensation resistor. 3. examination whether the sec ond phase compensation capacitor c2 is necessary or not is done. if the esr zero of output capacitor exists in a place that is smaller than half of the switching frequency, a second phase compensation capacitor is necessary. in other word s, it is the case wherein the formula below happens. in this case, add the second phase compensation capacito r c2, and match the frequency of the third pole to the frequency fp3 of esr zero. c2 is looked for using the following formula. 2 fs resr cout2 1 gcs gea fc cout 2 = vfb vout r3 fc r3 2 4 c1 r3 resr cout c2 =
19/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15 ? 001 i/o equivalent schematic pin. no pin. name pin equivalent schematic pin. no pin. name pin equivalent schematic 1 2 7 8 lx gnd bst vcc 5 sync 3 vc 6 en 4 fb bst vc lx gnd gnd sync vc vc gnd fb gnd en gnd
20/20 datasheet datasheet bd9673aefj tsz02201-0q1q0aj00190-1-2 ? 2013 rohm co., ltd. all rights reserved. 28.jan.2014 rev.003 www.rohm.com tsz22111 ? 15 ? 001 ordering part number b d 9 6 7 3 a e f j - e 2 part numbe r package efj : htsop-j8 packaging and forming specification e2: embossed tape and reel external information htsop-j8(top view) d9673a part number marking lot number 1pin mark
datasheet d a t a s h e e t notice - ge rev.002 ? 2014 rohm co., ltd. all rights reserved. notice precaution on using rohm products 1. our products are designed and manufac tured for application in ordinary elec tronic equipments (such as av equipment, oa equipment, telecommunication equipment, home electroni c appliances, amusement equipment, etc.). if you intend to use our products in devices requiring ex tremely high reliability (such as medical equipment (note 1) , transport equipment, traffic equipment, aircraft/spacecra ft, nuclear power controllers, fuel c ontrollers, car equipment including car accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or serious damage to property (?specific applications?), please consult with the rohm sale s representative in advance. unless otherwise agreed in writing by rohm in advance, ro hm shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any ro hm?s products for specific applications. (note1) medical equipment classification of the specific applications japan usa eu china class class class b class class class 2. rohm designs and manufactures its products subject to strict quality control system. however, semiconductor products can fail or malfunction at a certain rate. please be sure to implement, at your own responsibilities, adequate safety measures including but not limited to fail-safe desi gn against the physical injury, damage to any property, which a failure or malfunction of our products may cause. the following are examples of safety measures: [a] installation of protection circuits or other protective devices to improve system safety [b] installation of redundant circuits to reduce the impact of single or multiple circuit failure 3. our products are designed and manufactured for use under standard conditions and not under any special or extraordinary environments or conditio ns, as exemplified below. accordin gly, rohm shall not be in any way responsible or liable for any damages, expenses or losses arising from the use of an y rohm?s products under any special or extraordinary environments or conditions. if you intend to use our products under any special or extraordinary environments or conditions (as exemplified bel ow), your independent verification and confirmation of product performance, reliability, etc, prior to use, must be necessary: [a] use of our products in any types of liquid, incl uding water, oils, chemicals, and organic solvents [b] use of our products outdoors or in places where the products are exposed to direct sunlight or dust [c] use of our products in places where the products ar e exposed to sea wind or corrosive gases, including cl 2 , h 2 s, nh 3 , so 2 , and no 2 [d] use of our products in places where the products are exposed to static electricity or electromagnetic waves [e] use of our products in proximity to heat-producing components, plastic cords, or other flammable items [f] sealing or coating our products with resin or other coating materials [g] use of our products without cleaning residue of flux (ev en if you use no-clean type fluxes, cleaning residue of flux is recommended); or washing our products by using water or water-soluble cleaning agents for cleaning residue after soldering [h] use of the products in places subject to dew condensation 4. the products are not subjec t to radiation-proof design. 5. please verify and confirm characteristics of the final or mounted products in using the products. 6. in particular, if a transient load (a large amount of load applied in a short per iod of time, such as pulse. is applied, confirmation of performance characteristics after on-boar d mounting is strongly recomm ended. avoid applying power exceeding normal rated power; exceeding the power rating under steady-state loading c ondition may negatively affect product performance and reliability. 7. de-rate power dissipation (pd) depending on ambient temper ature (ta). when used in seal ed area, confirm the actual ambient temperature. 8. confirm that operation temperat ure is within the specified range descr ibed in the product specification. 9. rohm shall not be in any way responsible or liable for fa ilure induced under deviant condi tion from what is defined in this document. precaution for mounting / circuit board design 1. when a highly active halogenous (chlori ne, bromine, etc.) flux is used, the resi due of flux may negatively affect product performance and reliability. 2. in principle, the reflow soldering method must be used; if flow soldering met hod is preferred, please consult with the rohm representative in advance. for details, please refer to rohm mounting specification
datasheet d a t a s h e e t notice - ge rev.002 ? 2014 rohm co., ltd. all rights reserved. precautions regarding application examples and external circuits 1. if change is made to the constant of an external circuit, pl ease allow a sufficient margin c onsidering variations of the characteristics of the products and external components, including transient characteri stics, as well as static characteristics. 2. you agree that application notes, re ference designs, and associated data and in formation contained in this document are presented only as guidance for products use. theref ore, in case you use such information, you are solely responsible for it and you must exercise your own independent verification and judgment in the use of such information contained in this document. rohm shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of such information. precaution for electrostatic this product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. please take proper caution in your manufacturing process and storage so that voltage exceeding t he products maximum rating will not be applied to products. please take special care under dry condit ion (e.g. grounding of human body / equipment / solder iron, isolation from charged objects, se tting of ionizer, friction prevention and temperature / humidity control). precaution for storage / transportation 1. product performance and soldered connections may deteriora te if the products are stor ed in the places where: [a] the products are exposed to sea winds or corros ive gases, including cl2, h2s, nh3, so2, and no2 [b] the temperature or humidity exceeds those recommended by rohm [c] the products are exposed to di rect sunshine or condensation [d] the products are exposed to high electrostatic 2. even under rohm recommended storage c ondition, solderability of products out of recommended storage time period may be degraded. it is strongly recommended to confirm sol derability before using products of which storage time is exceeding the recommended storage time period. 3. store / transport cartons in the co rrect direction, which is indicated on a carton with a symbol. otherwise bent leads may occur due to excessive stress applied when dropping of a carton. 4. use products within the specified time after opening a hum idity barrier bag. baking is required before using products of which storage time is exceeding the recommended storage time period. precaution for product label qr code printed on rohm products label is for rohm?s internal use only. precaution for disposition when disposing products please dispose them proper ly using an authorized industry waste company. precaution for foreign exchange and foreign trade act since our products might fall under cont rolled goods prescribed by the applicable foreign exchange and foreign trade act, please consult with rohm representative in case of export. precaution regarding intellectual property rights 1. all information and data including but not limited to application example contain ed in this document is for reference only. rohm does not warrant that foregoi ng information or data will not infringe any intellectual property rights or any other rights of any third party regarding such information or data. rohm shall not be in any way responsible or liable for infringement of any intellectual property rights or ot her damages arising from use of such information or data.: 2. no license, expressly or implied, is granted hereby under any intellectual property rights or other rights of rohm or any third parties with respect to the information contained in this document. other precaution 1. this document may not be reprinted or reproduced, in whol e or in part, without prior written consent of rohm. 2. the products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written consent of rohm. 3. in no event shall you use in any wa y whatsoever the products and the related technical information contained in the products or this document for any military purposes, incl uding but not limited to, the development of mass-destruction weapons. 4. the proper names of companies or products described in this document are trademarks or registered trademarks of rohm, its affiliated companies or third parties.
datasheet datasheet notice ? we rev.001 ? 2014 rohm co., ltd. all rights reserved. general precaution 1. before you use our pro ducts, you are requested to care fully read this document and fully understand its contents. rohm shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny rohms products against warning, caution or note contained in this document. 2. all information contained in this docume nt is current as of the issuing date and subj ec t to change without any prior notice. before purchasing or using rohms products, please confirm the la test information with a rohm sale s representative. 3. the information contained in this doc ument is provi ded on an as is basis and rohm does not warrant that all information contained in this document is accurate an d/or error-free. rohm shall not be in an y way responsible or liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or concerning such information.

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