View BD9151MUV-E2_9001468.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. single-chip type with built-in fet switching regulator series output 1.5a or less high efficiency step-down switching regulator with built-in power mosfet bd9151muv description rohms high efficiency dual step-down switching regulato r bd9151muv is a power supply designed to produce a low voltage including 1.8 volts or 1.2 volts from 2.8 volts to 5.0 vo lts power supply line. reset circuits of input power supply voltage and external pch mosfet gate contro ller are incorporated. offers high efficiency with our original pulse skip control technology and synchronous rectifier. employs a current m ode control system to provide faster transient response to sudden change in load. features 1) offers fast transient response with current mode pwm control system. 2) offers highly efficiency for all load range with synchronous rectifier (pch/nch fet) and sllm tm (simple light load mode) 3) incorporates soft-start function. 4) incorporates thermal / ulvo protection functions. 5) incorporates thermal protection and short-current protection circuit with timer latch function. . 6) incorporates shutdown function icc=0a(typ.) 7) incorporates reset function 8) incorporates pch mosfet gate controller 9) employs small surface mount package : vqfn020v4040 applications power supply for lsi including dsp, micro computer and asic absolute maximum ratings (ta=25 ) parameter symbol limit unit vcc voltage av cc -0.3 +7 *1 v pvcc -0.3 +7 *1 v en voltage v en -0.3 +7 v sw voltage v sw 1 -0.3 +7 v v sw 2 -0.3 +7 v power dissipation pd1 0.34 *2 w pd2 0.70 *3 w pd3 2.21 *4 w pd4 3.56 *5 w operating temperature range topr -40 +85 storage temperature range tstg -55 +150 maximum junction temperature tjmax +150 *1 pd, aso and tj=150 should not be exceeded. *2 ic only *3 1-layer. mounted on a 74.2mm 74.2mm 1.6mm glass-epoxy board, occupied area by copper foil : 10.29mm 2 *4 4-layer. mounted on a 74.2mm 74.2mm 1.6mm glass-epoxy board, occupied area by copper foil : 10.29mm 2 , 2-3 layers 5505 mm 2 *5 4-layer. mounted on a 74.2mm 74.2mm 1.6mm glass-epoxy board, occupied area by copper foil : 5505mm 2 , in each layers operating conditions (ta=-40 +85 ) parameter symbol min. typ. max. unit vcc voltage av cc pv cc 2.8 3.3 5.5 v en voltage v en 0 - 5.5 v sw average output current i sw 1 - - 0.4 *6 a i sw 2 - - 0.8 *6 a *6 pd and aso should not be exceeded. no.09027ebt11 downloaded from: http:///
technical note bd9151muv 2/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. electrical characteristics (unless otherwise noted, ta=25 , avcc=pv cc =3.3v, en=av cc ) parameter symbol limit unit conditions min. typ. max standby current i stb - 0 10 a en=0v bias current i cc - 400 800 a en low voltage v enl - gnd 0.8 v in standby mode en high voltage v enh 2 vcc - v in active mode en input current i en - 1 10 a v en =2v oscillation frequency f osc 0.8 1.0 1.2 mhz pch fet on resistance r onp 1 - 0.27 0.46 ? av cc = pv cc =3.3v r onp 2 - 0.18 0.30 ? av cc = pv cc =3.3v nch fet on resistance r onn 1 - 0.27 0.46 ? av cc = pv cc =3.3v r onn 2 - 0.18 0.30 ? av cc = pv cc =3.3v i th sink current 1 i thsi 1 10 20 - a v fb 1=2.0v i th source current 1 i thso 1 10 20 - a v fb 1=1.6v i th sink current 2 i thsi 2 10 20 - a v fb 2=1.4v i th source current 2 i thso 2 10 20 - a v fb 2=1.0v fb reference voltage 1 fb1 1.773 1.800 1.827 v 1.5% fb reference voltage 2 fb2 1.182 1.200 1.218 v 1.5% uvlo threshold voltage v uvlol 2.4 2.5 2.6 v av cc =3.3 0v uvlo release voltage v uvloh 2.45 2.6 2.8 v av cc =0 3.3v reset threshold voltage p g 1 2.74 2.87 3.00 v av cc =3.3v 0v reset release voltage p g 2 2.84 2.97 3.10 v av cc =0v 3.3v reset on resistance r onpg - 140 240 ? reset delay t pg 8 16 32 ms moni discharge resistance r moni - 110 190 ? av cc =3.3v pgateb sink current i pgateb 1.5 4 6.5 ua soft start time t ss 0.25 0.5 1.0 ms timer latch time t latch 0.5 1.0 2.0 ms in scp/tsd operation output short circuit threshold voltage v scp 1 - 0.9 1.26 v fb1=1.8 0v v scp 2 - 0.6 0.84 v fb2=1.2 0v top view fig.1 bd9151muv top view vqfn020v4040 (unit :mm) 2.1 0.1 c0.2 0.5 1.0 15 610 11 15 16 20 4.0 0.1 4.0 0.1 2.1 0.1 0.4 0.1 0.25 +0.05 -0.04 0.02 +0.03 -0.02 1.0max. (0.22) 0.08 s s d9151 lot no. downloaded from: http:///
technical note bd9151muv 3/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. block diagram fig.2 bd9151muv block diagram pin no. & function table pin no. pin name pin function pin no. pin name pin function 1 pgnd2 ch2 low side source pin 11 agnd ground 2 pgnd2 ch2 low side source pin 12 avcc power supply input pin 3 pvcc2 ch2 high side fet source pin 13 pgateb external pch mos gate drive pin (low active) 4 pvcc1 ch1 high side fet source pin 14 pgate pgateb reverse logic output signal (high active) 5 pgnd1 ch1 low side source pin 15 moni 3.3v output monitor pin 6 sw1 ch1 pch/nch fet drain output pin 16 ith2 ch2 gmamp output pin / connected phase compensation capacitor 7 sw1 ch1 pch/nch fet drain output pin 17 fb2 ch2 output voltage detect pin 8 fb1 ch1 output voltage detect pin 18 en enable pin (high active) 9 ith1 ch1 gmamp output pin /connected phase compensation capacitor 19 sw2 ch2 pch/nch fet drain output pin 10 reset reset output pin 20 sw 2 ch2 pch/nch fet drain output pin current sense/ protect + driver logic soft start slope1 rs q osc vref scp/ tsd scp2 current sense/ protect + driver logic soft start/ delay slope2 rs q scp1 clk2 gm amp current comp gm amp current comp clk1 clk2 uvlo fb1 en fb2 pvcc1 sw1 pgnd2 sw2 agnd ith1 ith2 a gnd a vcc pvcc2 pgnd1 uvlo/ delay agnd moni pgateb reset pgood comp agnd v cc v cc vout1 vout2 vout2 vout1 v cc delay delay pgate v cc v cc vout3 downloaded from: http:///
technical note bd9151muv 4/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. characteristics data bd9151muv 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 -40-20 0 20406080 temperature:ta[ ] en voltage:ven[v] 0 25 50 75 100 125 150 175 200 225 250 275 300 -40 -20 0 20 40 60 80 100 temperature:ta[ ] on resistance:r on [m ] 0.8 0.9 1 1.1 1.2 2.8 3.3 3.8 4.3 4.8 5.3 input voltage:v cc [v] frequency:f osc [mhz] fi g .11 v cc -fosc 0.0 0.5 1.0 1.5 2.0 012345 input voltage:v cc [v] output voltage:vout[v] 0.0 0.5 1.0 1.5 2.0 01234 output current:i out [a] output voltage:vout[v] vout2=1.2v vout2=1.2v vcc=3.3v ta = 2 5 ta = 2 5 io=0a 0.0 0.5 1.0 1.5 2.0 012345 en voltage:ven[v] output voltage:vout[v] vcc=3.3v ta = 2 5 io=0a vout2=1.2v vcc=3.3v io=0a vout1=1.8v 0.8 1.0 1.2 -40-20 0 20406080 temperature:ta[ ] frequency:f osc [mhz] vcc=3.3v 0 100 200 300 400 500 600 -40-20 0 20406080 tem perature:ta[ ] circuit current:i cc [ a] vcc=3.3v fig.10 ta- fosc fig.8 vout1 efficiency fig. 6 ta-vout1 fig.3 v cc C vout1,vout2 fig.5 iout - vout fig.4 v en - vout fig.13 ta en1,en2 fig.14 ta icc fig.12 ta C ronn, ronp fig. 7 ta-vout1 vout2=1.2v O ta = 2 5 pmos nmos vcc=3.3v vout1=1.8v vout1=1.8v vout1=1.8v vout2=1.2v vcc=3.3v io=0a vcc=3.3v fig.9 vout2 efficiency 0 10 20 30 40 50 60 70 80 90 100 1 10 100 1000 output current:i out [ma] efficiency: [%] 1.75 1.78 1.80 1.83 1.85 -40 -20 0 20 40 60 80 temperature:ta[ ] output voltage:vout[v] vcc=3.3v io=0a vout1=1.8v 1.15 1.18 1.20 1.23 1.25 -40 -20 0 20 40 60 80 temperature:ta[ ] output voltage:vout[v] vout2=1.2v vcc=3.3v io=0a ta = 2 5 vcc=3.3v vout1=1.8v vcc=5v vout1=1.8v *vout2=1ma loaded 0 10 20 30 40 50 60 70 80 90 100 1 10 100 1000 output current:i out [ma] efficiency: [%] vcc=3.3v vout2=1.2v vcc=5v vout2=1.2v ta = 2 5 *vout1=1ma loaded downloaded from: http:///
technical note bd9151muv 5/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. fig.15 soft start waveform (io1=0ma,io2=0ma,io3=0ma) fig.16 soft start waveform (io1=400ma,io2=800ma,io3=600ma) fig.19 sw1 waveform (io=0ma) fig.20 sw1 waveform (io=400ma) fig.21 sw2 waveform (io=0ma) fig.22 sw2 waveform (io=800ma) fig.23 vout1 transient response (io=200ma 400ma / 10usec) fig.24 vout1 transient response (io=400ma 200ma/ 10usec) fig.26 vout2 transient response (io=800ma 400ma/ 10usec) fig.25 vout2 transient response (io=400ma 800ma/ 10usec) vout1 sw1 vout1 sw1 vout2 sw2 vout2 sw2 iout1 vout1 iout1 vout1 iout2 vout2 iout2 vout2 vcc=3.3v,ta=25 vout1 vout2 vout3 vcc=3.3v,ta=25 vout2 vout1 vout3 fig.17 soft start waveform (io1=0ma,io2=0ma,pgate) vcc=3.3v,ta=25 vout2 vout1 pgate fig.18 soft start waveform (io1=0ma,io2=0ma,reset) vout2 vout1 reset vcc=3.3v,ta=25 ,vout1=1.8v vcc=3.3v,ta=25 ,vout1=1.8v vcc=3.3v,ta=25 ,vout2=1.2v vcc=3.3v,ta=25 ,vout2=1.2v vcc=3.3v,ta=25 ,vout=1.8v vcc=5v,ta=25 ,vout=1.8v vcc=5v,ta=25 ,vout2=1.2v vcc=5v,ta=25 ,vout2=1.2v downloaded from: http:///
technical note bd9151muv 6/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. operation bd9151muv is a synchronous rectifying step-down switching regu lator that achieves faster transient response by employing current mode pwm control system. it utiliz es switching operation in pwm (pulse width modulation) mode for heavier load, while it utilizes sllm tm (simple light load mode) operation for lighter load to improve efficiency. synchronous rectifier it does not require the power to be dissipated by a rectifier externally connected to a conventional dc/dc converter ic, and its p.n junction shoot-through protection circuit limits the shoot-through current during operation, by which the power dissipation of the set is reduced. current mode pwm control synthesizes a pwm control signal with a inductor current feedback loop added to the voltage feedback. ? pwm (pulse width modulation) control the oscillation frequency for pwm is 1 mhz. set signal fo rm osc turns on a high side mos fet (while a low side mos fet is turned off), and an inductor current i l increases. the current comparator (current comp) receives two signals, a current feedback control sign al (sense: voltage converted from i l ) and a voltage feedback control signal (fb), and issues a reset signal if both input signals are identica l to each other, and turns off the high side mos fet (while a low side mos fet is turned on) for the rest of the fix ed period. the pwm control repeat this operation. ? sllm tm (simple light load mode) control when the control mode is shifted from pwm for heavier load to the one for lighter load or vise versa, the switching pulse is designed to turn off with the device held operated in normal pwm control loop, which allows linear operation without voltage drop or deterioration in transient response during the mo de switching from light load to heavy load or vise versa. although the pwm control loop continues to operate with a set signal from osc and a reset signal from current comp, it is so designed that the reset signal is held issued if shifted to the light load mode, with which the switching is tuned off and the switching pulses are thinned out under control. activating the switch ing intermittently reduces the switching dissipation and improves the efficiency. fig.27 diagram of current mode pwm control fig.28 pwm switching timing chart fig.29 sllm tm switching timing chart curren t comp set reset sw v out pvcc gnd gnd gnd i l (ave) v out (ave) sense fb curren t comp set reset sw v out pvcc gnd gnd gnd 0a v out (ave) sense fb i l not switching i l osc level shift driver logic rqs i l sw ith current comp gm amp. set reset fb load sense v out v out downloaded from: http:///
technical note bd9151muv 7/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. vcc en vout2(1.2v) tss(0.5ms) vout1(1.8v) discharge on pgate pgateb reset tss(0.5ms) delay1 (2ms) delay2 (4ms) tpg (16ms) delay1 (2ms) delay2 (4ms) tss tss tss delay1 (2ms) tss delay2 (4ms) discharge on vout3(3.3v) v uvlol (2.5v) v uvloh (2.6v) pg2 (2.97v) pg1 (2.87v) tpg (16ms) tpg (16ms) tss(1ms) tss(1ms) tss(1ms) discharge on description of operations ? soft start function en terminal shifted to high activates a soft-starter to gradually establish the output voltage with the current limited durin g startup, by which it is possible to prevent an ov ershoot of output voltage and an inrush current. ? shutdown function with en terminal shifted to low, the device turns to standby mode, and all the function blocks including reference voltage circuit, internal oscillator and drivers are turned to off. circuit current during standby is 0f (typ.). ? uvlo function detects whether the input voltage sufficient to secure the out put voltage of bu9151muv is supplied. and the hysteresis width of 100mv (typ.) is provided to prevent output chattering. each th e outputs have uvlo. it is possible to set output sequence easy. ? reset function when avcc input voltage is over .2.97v (typ), after 16msec (typ.) delay, outputs reset. the hysteresis is 100mv (typ). ? pch mosfet gate controller function pgateb pin has function to make fet active with steady current. with connecting pch mosfet gate, soft start turned to be on. ? discharge function moni pin is open drain pin of nch mos. after 4msec (typ) de lay from the time uvlo release, it turns to be off. by low, uvlo detection of en pin, nch mo s becomes active and discharge the connection. ? external synchronous signal output function pgate pin outputs high active after 4msec (t yp.) delay from the uvlo release. ? start up sequence function bu9151muv outputs output voltage 2ch (1.2v) after the uvlo release, and after 2msec(typ.) fr om the uvlo release, it outputs 1ch(1.8v), and the last, after 4msec from the uvlo release, pgateb bec omes active, and external pch mosfet will be on, and outputs 3ch(vcc equivalent). duri ng the off time, 3ch output is discharged by moni pin, then 1ch output and 2ch output are naturally discharged. *starting time of vout3 tss=1ms (when bd9151muv is used) it depends on gate capacity when using pch mosfet fig.30 soft start, shut down, uvlo timing chart downloaded from: http:///
technical note bd9151muv 8/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. ? short-current protection circuit with time latch function turns off the output to protect the ic fr om breakdown when the incorporated current limiter is activated continuously for the fixed time(t latch ) or more. the output thus held tuned off may be recovered by restarting en or by re-unlocking uvlo. fig.31 timer latch short-current protection timing chart switching regulator efficiency efficiency ? may be expressed by the equation shown below: efficiency may be improved by reducing the swit ching regulator power dissipation factors p d as follows: dissipation factors: 1) on resistance dissipation of inductor and fet pd(i 2 r) 2) gate charge/discharge dissipation pd(gate) 3) switching dissipation pd(sw) 4) esr dissipation of capacitor pd(esr) 5) operating current dissipation of ic pd(ic) 1)pd(i 2 r)=i out 2 (r coil +r on ) (r coil [ ] dc resistance of inductor, r on [ ] on resistance of fet, i out [a] output current.) 2)pd(gate)=cgs f v (cgs[f] gate capacitance of fet, f[h] switching frequency, v[v] gate driving voltage of fet) 4)pd(esr)=i rms 2 esr (i rms [a] ripple current of capacitor, esr[ ] equivalent series resistance.) 5)pd(ic)=vin i cc (i cc [a] circuit current.) scp threshold voltage i l limit en timer latch en standby mode a ctive mode a ctive mode standby mode en t2=t latch v out2 i l1 t1 technical note bd9151muv 9/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. consideration on permissible dissipation and heat generation as bu9151muv functions with high efficiency without significant heat generation in most applic ations, no special consideration is needed on permissible dissipation or heat generation. in case of extreme conditions, however, including lower input voltage , higher output voltage, heavier load, and/or higher temperature, the permissible dissi pation and/or heat generation must be carefully considered. for dissipation, only conduction losses due to dc resistance of in ductor and on resistance of fet are considered. because the conduction losses are considered to play the leading ro le among other dissipation mentioned above including gate charge/discharge dissipation and switching dissipation. if v cc =3.3v, v out1 =1.8v, v out2 =1.2v, r onh1 =0.27 , r onl1 =0.18 , r onh2 =0.27 , r onl2 =0.18 i out1 =0.4a, i out2 =0.8a, for example, d 1 =v out1 /v cc =1.8/3.3=0.55 d 2 =v out2 /v cc =1.2/3.3=0.36 r on1 =0.55 0.27+(1-0.55) 0.18 =0.1485+0.081 =0.2295[ ] r on2 =0.36 0.27+(1-0.36) 0.18 =0.0972+0.1152 =0.2124[ ] p=0.4 2 0.2295+0.8 2 0.2124=0.173[w] as r onh is greater than r onl in bu9151muv, the dissipation increases as the on duty becomes greater. with the consideration on the dissipation as above, thermal des ign must be carried out with sufficient margin allowed. fig.32 heat radiation characteristics (vqfn020v4040) p=i out 2 r on r on =d r onh +(1-d)r onl d on duty(=v out /v cc ) r onh on resistance of high side mos fet r onl on resistance of low side mos fet i out output current 0 25 50 75 100 125 150 0 2.0 3.0 4.0 2.21w 3.56w power dissipation :pd [w] 1.0 0.70w 0.34w 4 ? ( ??~ 5505mm 2 ) ( ?~e ) j-a=35.1 /w 4 ? ( ??~ 10.29mm 2 ) (2,3 ?~e 5505mm 2 ) j-a=103.3 /w 1 ? ( ??~ 10.29mm 2 ) j-a=178.6 /w ic gr j-a=367.6 /w 105 ambient temperature :ta [ ] 4 layers (copper foil area : 5505mm 2 ) (copper foil in each layers) j-a=35.1 /w 4 layers (copper foil area : 10.29mm 2 ) (copper foil in 2-3 layers: 5505mm 2 ) j-a=103.3 /w 1 layer (copper foil area : 10.29mm 2 ) j-a=178.6 /w ic only j-a=367.6 /w downloaded from: http:///
technical note bd9151muv 10/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. selection of components externally connected 1. selection of inductor (l) current exceeding the current rating of the inductor results in magnetic saturation of the inductor, which decreases efficiency . the inductor must be selected allowing sufficient margin with which the peak current may not exceed its current rating. if v cc =3.3v, v out =1.8v, f=1.0mhz, i l =0.3 0.8a=0.24a, for example,(bd9151muv) select the inductor of low resistance component (such as dcr and acr) to minimize dissipation in the inductor for better efficiency. 2. selection of output capacitor (c o ) the inductance significantly depends on output ripple current. a s seen in the equation (1), the ri pple current decreases as the i nductor and/or switching frequency increases. i l = (v cc -v out ) v out l v cc f [ a ] ??? ( 1 ) a ppropriate ripple current at output should be 20% more or less of the maximum output current. i l =0.3 i out max. [a] ??? (2) l= (v cc -v out ) v out i l v cc f [ h ] ??? ( 3 ) ( i l : output ripple current, and f: switching frequency) output capacitor should be selected with the consideration on the stability region and the equivalent series resistance re quired to smooth ripple voltage. output ripple voltage is determined by the equation (4) v out = i l esr [v] ??? (4) ( i l : output ripple current, esr: equivalent series resistance of output capacitor) rating of the capacitor should be determined allowing sufficient margin against output voltage. a 22 f to 100 f ceramic capacitor is recommended. less esr allows reduction in output ripple voltage. fig.34 output capacitor l= =2.02 2.2[ h] fig.33 output ripple current i l v out i l v cc il l co v cc l co v out esr ( 3.3-1.8 ) 1.8 0.24 3.3 1.0m downloaded from: http:///
technical note bd9151muv 11/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. 3. selection of input capacitor (cin) a low esr 22f/10v ceramic capacitor is recommended to reduc e esr dissipation of input capacitor for better efficiency. 4. determination of rith, cith that works as a phase compensator as the current mode control is designed to limit a inductor current, a pole (phase lag) appears in the low frequency area due to a cr filter consisting of a output capacitor and a load resistance, while a zero (phase lead) appears in the high frequency area due to the output capacitor and its esr. so, adding a zero to the power amplifier output with c easily compensates the phases and r as described below to cancel a pole at the power amplifier. input capacitor to select must be a low esr capacitor of the capacitance sufficient to cope with high ripple current to prevent high transient voltage. the ripple current irms is given by the equation (5): i rms =i out v out ( v cc -v out ) v cc [a] ??? ( 5 ) when vcc=2 v out , i rms = i out 2 < worst case > i rms(max.) i rms =2 1.8 ( 5.0-1.8 ) 5.0 =0.48 [ a rms ] fig.36 open loop gain characteristics fig.37 error amp phase compensation characteristics fp= 2 r o c o 1 fz (esr) = 2 e sr c o 1 pole at power amplifier when the output current decreases, the load resistance ro increases and the pole frequency lowers. fp (min.) = 2 r omax. c o 1 [hz] with lighter load fp (max.) = 2 r omin. c o 1 [hz] with heavier load zero at power amplifier fz (amp.) = 2 r ith c ith 1 fig.35 input capacitor v out v cc l co cin gain [db] phase [deg] a 00 -90 a 00 -90 fz(amp.) fp(min.) fp(max.) fz(esr) i out min. i out max. gain [db] phase [deg] increasing capacitance of the output capacitor lowers the pole frequency while the zero frequency does not change. (this is because when the capacitance is doubled, the capacitor esr reduces to half.) if v cc =5.0v, v out =1.8v, and i outmax.=0.4 a, (bd9151muv) downloaded from: http:///
technical note bd9151muv 12/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. stable feedback loop may be achieved by canceling the pole fp (min.) produced by the output capacitor and the load resistance with cr zero correction by the error amplifier. fig.38 external parts sketch l2 l1 v out1 agnd reset ith1 fb1 sw1 fb2 en sw2 avcc pgateb pgate ith2 pgnd1 pvcc1 pvcc2 pgnd2 v out2 c out 1 c in 1 c in 2 c out 2 sw2 r ith2 c ith2 sw1 r ith1 c ith1 v out3 moni pgnd2 c out 3 r 1 u1 fz (amp.) = fp (min.) 2 r ith c ith 1 = 2 r omax. c o 1 downloaded from: http:///
technical note bd9151muv 13/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. bd9151muv caution of board layout fig.39 example of board layout lay out the input ceramic capacitor cin closer to the pi ns pvcc and pgnd, and the output capacitor co closer to the pin pgnd. lay out cith and rith between the pi ns ith and gnd as neat as possible with least necessary wiring. vqfn020v4040 (bd9151muv) has thermal pa d on the reverse of the package. the package thermal performance may be enhanced by bonding the pad to gnd plane which take a large area of pcb. recommended parts list, using the application above symbol parts name value company parts number l1,2 inductor 2.2h tdk ltf5022-2r2n3r2 taiyo yuden nr3012t2r2m c in1, c in2 ceramic capacitor 22f murata grm32eb11a226ke20 c out1, c out2 ceramic capacitor 22f murata grm31cb30j226ke18 c ith1 ceramic capacitor 330pf murata grm18 series r ith1 resistor 22k ? rohm mcr03 series c ith2 ceramic capacitor 220pf murata grm18 series r ith2 resistor 15k ? rohm mcr03 series u1 pch fet - rohm rt1a040zp cout3 ceramic capacitor 22f murata grm31cb30j226ke18 r1 resistor 10k ? rohm mcr03 series the parts list presented above is an example of recommend ed parts. although the parts are sound, actual circuit characteristics should be checked on your application carefully before use. be sure to allow sufficient margins to accommodate variations between external devices and bu91 51muv when employing the depicted circuit with other circuit constants modified. both static and transient characte ristics should be considered in establishing these margins. when switching noise is substantial and may impact the system, a low pass filter should be inserted between the v cc and pvcc pins, and a schottky barrier diode or snubber established between the sw and pgnd pins. r 1 l2 l1 v out1 agnd reset ith1 fb1 sw1 fb2 en sw2 avcc pgateb pgate ith2 pgnd1 pvcc1 pvcc2 pgnd2 v out2 c out 1 c in 1 c in 2 c out 2 sw2 r ith2 c ith2 sw1 r ith1 c ith1 v out3 moni pgnd2 c out 3 u1 downloaded from: http:///
technical note bd9151muv 14/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. i/o equivalent circuits fig.40 i/o equivalent circuits en ? en pin ? sw1,sw2 pv cc sw1,sw2 pv cc pv cc ith1,ith2 ? ith1,ith2 pin a v cc ? fb1,fb2 pin fb1,fb2 reset,moni ? reset,moni pin ? pgateb pin pgateb ? pgate pin pgate a v cc a v cc a v cc downloaded from: http:///
technical note bd9151muv 15/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. notes for use 1. absolute ma ximum ratings while utmost care is taken to quality control of this pr oduct, any application that may exceed some of the absolute maximum ratings including the voltage applied and the operat ing temperature range may result in breakage. if broken, short-mode or open-mode may not be identif ied. so if it is expected to encounter with special mode that may exceed the absolute maximum ratings, it is requested to take necessary sa fety measures physically including insertion of fuses. 2. electrical potential at gnd gnd must be designed to have the lowest elec trical potential in any operating conditions. 3. short-circuiting between terminals, and mis-mounting when mounting to pc board, care must be taken to avoid mistak e in its orientation and alignment. failure to do so may result in ic breakdown. short-circuiting due to forei gn matters entered between output terminals, or between output and power supply or gnd may also cause breakdown. 4. thermal shutdown protection circuit thermal shutdown protection circuit is the circuit designed to isolate the ic from thermal runaway, and not intended to protect and guarantee the ic. so, the ic the thermal shutdown protection circui t of which is once activated should not be used thereafter for any operation originally intended. 5. inspection with the ic set to a pc board if a capacitor must be connected to the pin of lower impeda nce during inspection with the ic set to a pc board, the capacitor must be discharged after each process to avoid stress to the ic. for electrostatic protection, provide proper grounding to assembling processes with special care taken in handling and storage. when connecting to jigs in the inspection process, be sure to turn off the power supply before it is connected and removed. 6. input to ic terminals this is a monolithic ic with p + isolation between p-substrate and each element as illustrated below. this p-layer and the n-layer of each element form a p-n junction, and various parasitic element are formed. if a resistor is joined to a transistor terminal as shown in fig 41. p-n junction works as a parasitic diode if the following rela tionship is satisfied; gnd>terminal a (at resistor side), or gnd>terminal b (at transistor side); and if gnd>terminal b (at npn transistor side), a parasitic npn transistor is activated by n-layer of ot her element adjacent to the above-mentioned parasitic diode. the structure of the ic inevitably forms parasitic elements, the activation of which may cause interference among circuits, and/or malfunctions contributing to breakdown . it is therefore requested to take care not to use the device in such manner that the voltage lowe r than gnd (at p-substrate) may be applied to the input terminal, which may result in activation of parasitic elements. fig.41 simplified structure of monorisic ic 7. ground wiring pattern if small-signal gnd and large-current gnd are provided, it will be recommended to separate the large-current gnd pattern from the small-signal gnd pattern and establish a si ngle ground at the reference poi nt of the set pcb so that resistance to the wiring pattern and voltage fluctuations due to a large current will cause no fluctuations in voltages of the small-signal gnd. pay attention not to cause fluctuations in the gnd wiring pattern of external parts as well. 8 . selection of inductor it is recommended to use an inductor with a series resistance element (dcr) 0.1 or less. especially, in case output voltage is set 1.6v or more, note that use of a high dcr i nductor will cause an inductor loss , resulting in decreased output voltage. should this condition continue for a specified peri od (soft start time + timer la tch time), output short circuit protection will be activated and output will be latched off. when using an inductor over 0.1 , be careful to ensure adequate margins for variation between external devices and bu9151muv, including transient as well as static characteristics. furthermore, in any case, it is recommended to start up the output with en after supply voltage is within operation range. resistor transistor (npn) n n n p + p + p p substrate gnd parasitic element pin a n n p + p + p p substrate gnd parasitic element esr c b e n gnd pin a p aras iti c element pin b other adjacent elements e b c gnd p aras iti c element downloaded from: http:///
technical note bd9151muv 16/16 www.rohm.com 2009.09 - rev.b ? 2009 rohm co., ltd. all rights reserved. ordering part number b d 9 1 5 1 m u v - e 2 part no. part no. package muv: vqfn20v4040 packaging and forming specification e2: embossed tape and reel (vqfn20v4040) ? order quantity needs to be multiple of the minimum quantity. embossed carrier tape tapequantity direction of feed the direction is the 1pin of product is at the upper left when you hold reel on the left hand and you pull out the tape on the right hand 2500pcs e2 () direction of feed reel 1pin (unit : mm) vqfn020v4040 2.1 0.1 1 15 11 2016 5 10 6 0.5 1.0 0.25 +0.05 - 0.04 2.1 0.1 0.4 0.1 c0.2 1.0max 0.02 +0.03 - 0.02 (0.22) 4.0 0.1 4.0 0.1 1pin mark 0.08 s s downloaded from: http:///
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, rohm shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any ro hms 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 rohms 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 below), 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 described 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 downloaded from: http:///
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 considering 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 humidity 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 rohms 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 contained 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. downloaded from: http:///
datasheet datasheet notice C 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. downloaded from: http:///

▲Up To Search▲

Price & Availability of BD9151MUV-E2

	To Download BD9151MUV-E2 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .