View XC9510BXXXSX_5198505.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1351 xc9510 etr1007_001.doc synchronous step-down dc/dc converter with built-in ldo regulator plus voltage detector step-down dc/dc converter's output connected in series with ldo regulator high efficiency, low noise regulated output sop-8 package for high current small-footprint output current dc/dc:800ma, vr: 400ma ceramic capacitor compatible (low esr capacitors) general description the xc9510 series consists of a step-down dc/dc converte r and a high-speed ldo regulator connected in series with the dc/dc converter's output. a voltage detector is also built-in. a highly efficient, low noise output is possible since the regulator is stepped-down further from the dc/dc output. the dc/dc converter block incorporates a p-channel drive r transistor and a synchronous n-channel switching transistor. with an external coil, diode and two capacitors, the xc9510 can deliver output currents up to 800ma at efficiencies ove r 90%. the xc9510 is designed for use with small ceramic capacitors. a choice of three switching frequencies are available, 300 khz, 600 khz, and 1.2 mhz. output voltage settings for the dc/dc is set-up internally in 100mv steps within the range of 1.6v to 4.0v( 2.0%) and for the vr are set-up internally within the range of 0.9v to 4.0v ( 2.0%). for the vd, the range is of 0.9v to 5.0v ( 2.0%). the sof t start time of the series is inte rnally set to 5ms. with the built-in u.v.l.o. (under voltage lock out) function, the internal p-channel driver transistor is forced off when input voltage becomes 1.4 v or lower. the operational states o f the dc/dc and the regulator blocks can be changed b y inputting three kinds of voltage level via the ce/mode pin. the functions of the mode pin can be selected via the external control pin to switch the dc/dc control mode and the disable pin to shut down the regulator block. a pplications cd-r / rw, dvd hdd pdas, portable communication modem cellular phones palmtop computers cameras, video recorders typical application circuit features input voltage range : 2.4v ~ 6.0v low esr capacitor : ceramic capaci tor compatible (low esr capacitors) vd function : detects output voltage from the v dout pin while sensing either v dd , d cout , or v rout internally. n-ch open drain output output voltage range : 1.6v ~ 4.0v (accuracy 2%) output current : 800ma controls : pwm control, pwm, pwm/pfm automatic switching external oscillation frequency : 300khz, 600khz, 1.2mhz output voltage range : 0.9v ~ 4.0v (accuracy 2%) current limit : 600ma dropout voltage : 160mv @ i out =200ma (v out =2.8v) high ripple rejection : 60db @1khz (v out =2.8v) typical performance characteristics
1352 xc9510 series pin configuration sop-8 (top view) pin assignment designator description symbol description control methods and the vd sense pin as chart below : - ? setting voltage & specifications internal standard : setting voltage and specificat ions of each dc/dc, vr, and vd based on the internal standard) 3 : 300khz 6 : 600khz dc/dc oscillation frequency c : 1.2mhz package s : sop-8 r : embossed tape, standard feed device orientation l : embossed tape, reverse feed series type dc/dc control methods ce=?vceh? level ce=?vcem? level ce=?vcel? level vd sense pin a v dd b d cout c - - dc/dc: off vr: off vd: on v rout d v dd e d cout f pwm control dc/dc: on vr: off vd: on dc/dc: on vr: on vd: on dc/dc: off vr: off vd: on v rout h v dd k d cout xc9510 l pwm, pfm/pwm manual switch pfm / pwm automatic switch pwm control dc/dc: off vr: off vd: on v rout pin number pin name function 1 p gnd power ground 2 ce/mode chip enable / mode switch 3 v dd power supply 4 v dout vd output 5 a gnd analog ground 6 v rout vr output 7 d cout dc/dc output 8 lx switch product classification ordering information xc9510 ????? the input for the voltage regul ator block comes from the dc/dc. control methods, ce/mode pin, vdsense pin
1353 x c9510 series mark product series 1 0 xc9510****s* mark dc/dc control ce/mode pin (h level) ce/mode pin (m level) ce/mode pin (l level) vd sense product series a v dd xc9510a***s* b dc out xc9510b***s* c - - vr out xc9510c***s* d v dd xc9510d***s* e dc out xc9510e***s* f pwm control vr:off vr:on vr out xc9510f***s* h v dd xc9510h***s* k dc out xc9510k***s* l pwm,pfm/pwm manual switch pfm/pwm auto switch pwm control dc/dc:off vr:off vd:on vr out xc9510l***s* marking rule sop-8 ? represents product series represents dc/dc control methods, ce/mode pins and vd sense pin packaging information sop-8 sop-8 (top view)
1354 xc9510 series mark dc/dc vr vd 1 3 3.3v 1.8v 4. 0v xc9510*13*s* mark oscillation frequency product series 3 300khz xc9510***3a* 6 600khz xc9510***6a* c 1.2mhz xc9510***ca* mark production year 3 2003 4 2004 block diagram represents production lot number 0 to 9,a to z reverse character 0 to 9, a to z repeated (g,i,j,o,q,w excepted) note: no character inversion used * diodes shown in the above circuit are p rotective diodes. ? represents detect voltage dc/dc,vr and vd ex) represents last digit of production year. ex ) represents oscillation frequency . marking rule (continued) product series
1355 x c9510 series parameter symbol ratings unit v dd pin voltage vdd - 0.3 ~ 6.5 v dc out pin voltage dc out - 0.3 ~ v dd + 0.3 v vr out pin voltage vr out - 0.3 ~ v dd + 0.3 v vr out pin current ir out 800 ma vd out pin voltage vd out - 0.3 ~ v dd + 0.3 v vd out pin current i vd 50 ma lx pin voltage lx - 0.3 ~ v dd + 0.3 v lx pin current ilx 1300 ma ce/mode pin voltage ce/mode - 0.3 ~ v dd + 0.3 v power dissipation sop-8 pd 650* mw operating temperature range topr - 40 ~ + 85 storage temperature range tstg - 55 ~ + 125 a bsolute maximum ratings ta = 2 5 (*) when pc board mounted.
1356 xc9510 series parameter symbol conditions min. typ. max. units circuit supply current 1 i dd 1 v in =ce=d cout =5.0v - 250 310 a 1 supply current 2 i dd 2 v in =ce=5.0v, d cout =0v - 300 360 a 1 stand-by current (*1) i stb v in =6.5v, ce=0v - 3.0 7.0 a 1 input voltage range v in 2.4 - 6.0 v - ce ?h? level voltage *xc9510d/e/f v ceh v dd -0.3 - v dd v 2 ce ?h? level voltage *xc9510h/k/l v ceh v dd -0.3 - v dd v 3 ce ?m? level voltage v cem 0.6 - v dd -1.2 v 3 ce ?l? level voltage v cel v ss - 0.25 v 3 ce ?h? level current i ceh - 0.1 - 0.1 a 1 ce ?l? level current i cel - 0.1 - 0.1 a 1 parameter symbol conditions min. typ. max. units circuit supply current 1 *xc9510d/e/f i dd _dc1 v in =ce=d cout =5.0v - 200 280 a 1 supply current 2 *xc9510d/e/f i dd _dc2 vi n =ce=5.0v, d cout =0v - 250 330 a 1 pfm supply current 1 *xc9510h/k/l i dd _pfm1 v in =ce=d cout =5.0v - 250 310 a 1 pfm supply current 2 *xc9510h/k/l i dd _pfm2 v in =ce=5.0v, d cout =0v - 300 360 a 1 output voltage dc out (e) connected to the external components, i dout =30ma 2.156 2.200 2.244 v 3 oscillation frequency f osc connected to the external components, i dout =10ma 1.02 1.20 1.38 mhz 3 maximum duty ratio maxduty d cout =0v 100 - - % 4 minimum duty ratio minduty d cout =v in - - 0 % 4 pfm duty ratio pfmduty connected to the external components, no load 21 30 38 % 3 u.v.l.o. voltage (*2) vuvlo connected to the external components 1.00 1.40 1.78 v 3 lx sw ?high? on resistance (*3) rlxh d cout =0v, lx=v in -0.05v - 0.5 0.9 5 lx sw ?low? on resistance rlxl connected to the external components, v in =5.0v - 0.5 0.9 3 lx sw ?high? leak current (*12) ileakh v in =lx=6.0v, ce=0v - 0.05 1.00 a 11 lx sw ?low? leak current (*12) ileakl v in =6.0v, lx=ce=0v - 0.05 1.00 a 11 maximum output current imax1 connected to the external components 800 - - ma 3 current limit (*9) ilim1 1.0 1.1 - a 6 efficiency (*4) effi connected to the external components, i dout =100ma - 90 - % 3 output voltage i dout =30ma temperature characteristics u dc out u to p r ? dc out -40 Q topr Q 85 - + 100 - ppm/ 3 soft-start time tss connected to the external components, ce=0v t v in , i dout =1ma 2 5 10 ms 3 latch time (*5, 10) tlat connected to the external components, v in =ce=5.0v, short d cout by 1 resistor - 8 25 ms 10 electrical characteristics xc9510xxxcsx common characteristics topr=25 dc/dc converter (2.2v product) topr=25
1357 x c9510 series parameter symbol conditions min. typ. max. units circuit output voltage vr out (e) ir out =30ma 1.764 1.800 1.836 v 2 maximum output current imax2 400 - - ma 2 load regulation u vr out 1ma Q ir out Q 100ma - 15 50 mv 2 dropout voltage 1 (*6) vdif 1 ir out =100ma - 100 200 mv 2 dropout voltage 2 vdif 2 ir out =200ma - 200 400 mv 2 ir out =30ma line regulation u vrout u v in ? vr out vr out (t)+1v Q v in Q 6v - 0.05 0.25 %/v 2 current limit ilim2 vr out =vr out (e) x 0.9 480 600 - ma 7 short-circuit current ishort vr out =vss - 30 - ma 7 ripple rejection rate psrr v in ={v out (t)+1.0} v dc +0.5vp-pac, ir out =30ma, f=1khz - 60 - db 12 output voltage ir out =30ma temperature characteristics u vr out u to p r ? vr out -40 Q topr Q 85 - + 100 - ppm/ 2 parameter symbol conditions min. typ. max. units circuit detect voltage v df (e) ce=0v 2.646 2.700 2.754 v 8 hysteresis range v hys v hys =[v dr (e) (*11) - v df (e)] / v df (e) x 100 2 5 8 % 8 vd output current ivd vdout=0.5v, ce=0v 1 - - ma 9 output voltage temperature characteristics u v df u to p r ? v df -40 Q topr Q 85 - + 100 - ppm/ 8 electrical characteristics (continued) xc9510xxxcsx (continued) regulator (1.8v product) topr=25 detector (2.7v product) test conditions: unless otherwise stated: dc/dc : vin=3.6v [@ dc out :2.2v] vr: v in = 2.8v (v in =vr out (t) + 1.0v) vd: v in =5.0v common conditions for all test items: ce=v in , mode=0v * vr out (t) : setting output voltage note: *1 : including vd supply current (vd operates when in stand-by mode.) *2 : including hysteresis operating voltage range. *3 : on resistance ( )= 0.05 (v) / ilx (a) *4 : effi = { ( output voltage x output current ) / ( input voltage x input current) } x 100 *5 : time until it short-circuits dc out with gnd through 1 of resistance from a state of operation and is set to dc out =0v from current limit pulse generating. *6 : vdif = (v in 1 (*7) - vr out 1 (*8) ) *7 : v in 1 = the input voltage when vr out 1 appears as input voltage is gradually decreased. *8 : vr out 1 = a voltage equal to 98% of the output voltage whenever an amply stabilized i out {vr out (t) + 1.0v} is input. *9 : current limit = when v in is low, limit current may not be reached bec ause of voltage falls caused by on resistance o r serial resistance of coils. *10: integral latch circuit=latch time may bec ome longer and latch operation may not work when v in is 3.0v or more. *11: v dr (e) = vd release voltage *12: when temperature is high, a current of approximately 5.0 a (maximum) may leak.
1358 xc9510 series circuit 1 supply current, stand-by current, ce current ci rcuit 2 output voltage (vr), load regulation, dropout voltage, maximum output current, (mode voltage) circuit 3 output voltage (dc/dc) oscillation frequency, u.v.l.o. voltage, soft-start time, ce voltage, circuit 4 minimum duty cycle, maximum duty cycle maximum output current, effi ciency, (pfm duty cycle), (mode voltage) circuit 5 lx on resistance circ uit 6 current limit 1 (dc/dc) test circuits 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd cin : 1.0uf (ceramic) a a dcout : vin or gnd v irout v cin : 4.7uf (ceramic) ce/mode : vin or vin-1.2v or gnd 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd cl:4.7uf(ceramic, irout<300ma ) 10uf(ceramic, irout>300ma) v ce : vin a cin : 1.0uf (ceramic) 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd ce : vin cin : 4.7uf (ceramic) ilx 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd a probe cin : 4.7uf (ceramic) v cl : 10uf (ceramic) v l idout 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd probe fosc 300khz 600khz 1.2mhz l 22uh(c drh6d38, sumida) 10uh(c drh5d28, sumida) 4.7uh(cdrh4d28c, sumida) cin : 1.0uf(ceramic) v ce : vin 200 ? 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd probe
1359 x c9510 series circuit 7 current limit 2 (vr), short ci rcuit current (vr) circui t 8 detect voltage, release voltage (hysteresis range) * for the measurement of the vdd_sense products, the input voltage was controlled. circuit 9 vd output current circuit 10 latch time circuit 11 off-leak circui t 12 ripple rejection rate test circuits ( continued ) cin : 1uf (ceramic) v ce : vss a vd_sense* (dcout or vrout) 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd cin: 1uf v ce/mode : vss 200k ? 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd vd_sense* (dcout or vrout) v cin : 4.7uf (ceramic) v cl : 10uf (ceramic) v l 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd fosc 300khz 600khz 1.2mhz l 22uh( cdrh6d38, sumida) 10uh( cdrh5d28, sumida) 4.7uh(cdrh4d28c, sumida) 1 ? v irout v 1 2 3 4 8 7 6 5 vdd ce/ mode vdout agnd lx dcout vrout pgnd cin : 4.7uf (ceramic) ce/mode : vin or vin-1.2v or gnd cl:4.7uf(ceramic, irout<300ma ) 10uf(ceramic, irout> 300ma) ~ v ce/mode : vss a cin : 1.0uf (ceramic) 1 2 3 4 8 7 5 6 vdd ce/ mode agnd lx dcout vrout vdout pgnd a a * for the measurement of the vdd_sense products, the input voltage was controlled.
1360 xc9510 series fosc l 1.2mhz 4.7 h (cdrh4d28c, sumida) 600khz 10 h (cdrh5d28, sumida) 300khz 22 h (cdrh6d28, sumida) cin cl1 cl2 * 2 ir out< 300ma 4.7 f (ceramic, taiyo yuden) 4.7 f(ceramic, taiyo yuden) 10 f(ceramic, taiyo yuden) ir out > 300ma 10 f (ceramic, taiyo yuden) typical application circuit sop-8 (top view) *1 the dc/dc converter of the xc9510 series automatically switches between synchronous / non-synchronous. the schottk y diode is not normally needed. however, in cases where high effici ency is required when using the dc/dc converter during in the light load while in non-synchronous operation, please connect a schottky diode externally. *2 please be noted that the recommend value above of the cl2 may be changed depending on the input voltage value and setting voltage value. operational explanation the xc9510 series consists of a synchronous step-down dc/dc converter, a high speed ldo voltage regulator, and a voltage detector. since the ldo voltage regulator is stepped- down from the dc/dc?s output,high efficiency and low noise is possible even at lower output voltages. dc/dc converter the series consists of a reference voltage source, ramp wave circuit, error amplifier, pwm comparator, phase compensation circuit, output voltage adjustment resistors, dr iver transistor, synchronous switch, current limiter circuit, u.v.l.o. circuit and others. the series ics compare, usin g the error amplifier, the voltage of the internal voltage reference source with the feedback voltage from the v out pin through split resistors. phase compensation is performed on the resulting error amplifier output, to input a signal to the pwm comparator to determine the turn-on time during pwm operation. the pwm comparator compares, in te rms of voltage level, the signal from the error amplifie r with the ramp wave from the ramp wave circuit, and delivers t he resulting output to the buffer driver circuit to cause the lx pin to output a switching duty cycle. this process is continuously performed to ensure stable output voltage. the current feedback circuit monitors the p-channel mos driv er transistor current for each switching operation, and modulates the error amplifier output signal to provide mu ltiple feedback signals. this enables a stable feedback loop even when a low esr capacitor, such as a ceramic capacitor, is used, ensuring stable output voltage. the reference voltage source provides the reference voltage to ensure stable output volt age of the dc/dc converter. the ramp wave circuit determines switching frequency. t he frequency is fixed internally and can be selected from 300khz, 600 khz and 1.2 mhz. clock pulses generated in this circuit are used to produce ramp waveforms needed fo r pwm operation, and to synchronize all the internal circuits. the error amplifier is designed to monitor output voltage. the amplifier compares the reference voltage with the feedback voltage divided by the internal split resistors. wh en a voltage lower than the reference voltage is fed back, the output voltage of the error amplifier in creases. the gain and frequency characteri stics of the error amplifier output are fixed internally to deliver an optimized signal to the mixer.
1361 x c9510 series operational explanation ( continued ) the xc9510a to f series are pwm control, while the xc9510h to l series can be automatically switched between pwm control and pwm/pfm control. the pwm of the xc9510a to f series are contro lled on a specified frequency from light loads through the heavy loads. since the frequency is specif ied, the composition of a noi se filter etc. becomes easy. however, the efficiency at the time of the light load may become low. the xc9510h to l series can switch in any timing betwe en pwm control and pwm/pfm aut omatic switching control. the series cannot control only pfm mode. if needed, the operation can be set on a specified frequency; therefore, the control of the noise etc. is possible and the high efficiency at the time of the light load during pfm control mode is possible. with the automatic pwm/pf m switching control function, the seri es ics are automatically switched from pwm control to pfm control mode under light load conditions . if during light load conditions the coil current becomes discontinuous and on-time rate falls lower than 30%, the pf m circuit operates to output a pulse with 30% of a fixed on-time rate from the lx pin. during pfm operation with this fixed on-time rate, pulses are generated at different frequencies according to conditions of the moment. this c auses a reduction in the number of switching operations pe r unit of time, resulting in efficiency improvement under light load conditions. however, since pulse output frequency is not constant, consideration should be given if a noise filter or the like is needed. necessary conditions for switching to pfm operation depend on input voltage, load current, coil value and other factors. the xc9510 series automatically switches between synchrono us / non-synchronous accordi ng to the state of the dc/dc converter. highly efficient operations are achievable using the synchronous mode while the co il current is in a continuous state. the series enters non-synchronous operation when the built- in n-ch switching transistor for synchronous operation is shutdown which happens when the load current becomes lo w and the operation changes to a discontinuous state. the ic can operate without an external schottky diode bec ause the parasitic diode in the n-ch switching transisto r provides the circuit's step-down operation. however, since vf of the parasitic diode is a high 0.6v, the efficiency level during non-synchronous operation shows a s light decrease. please use an external schottky diode if high efficiency is required during light load current. continuous mode: synchronous discontinuous mode: non-synchronous
1362 xc9510 series the current limiter circuit of the xc9510 series monito rs the current flowing through the p-channel mos drive r transistor connected to the lx pin, and f eatures a combination of t he constant-current type current limit mode and the operation suspension mode. when the driver current is greater th an a specific level, the constant-curr ent type current limit function operates to turn off the pulses from the lx pin at any given timing. when the driver transistor is turned off, the limiter circui t is then released from the current limit detection state. at the next pulse, the driver transisto r is turned on. however, the transistor is immediately turned off in the case of an over current state. when the over current state is eliminat ed, the ic resumes its normal operation. the ic waits for the over current st ate to end by repeating the steps through . if an over current state continues for 8msec* and the above three steps are repeat edly performed, the ic perfo rms the function of latching the off state of t he driver transistor, and goes into operation susp ension mode. once the ic is in suspension mode, operations can be resumed by ei ther turning the ic off via the ce/mod e pin, or by restoring power to the v in pin. the suspension mode does not mean a comple te shutdown, but a state in which pulse output is suspended; therefore, the internal circ uitry remains in operation. the const ant-current type current limit of the xc9510 series can be set at 1.1a. operational explanation ( continued ) when the v in pin voltage becomes 1.4 v or lower, the p-channel out put driver transistor is forced off to prevent false pulse output caused by unstable operation of the internal circuitry. when the v in pin voltage becomes 1.8 v or higher, switching operation takes place. by re leasing the u.v.l.o. function, the ic performs the soft start function to initiate output startup operation. the soft st art function operates even when the v in pin voltage falls momentarily below the u.v.l.o. operating voltage. the u.v.l.o. circuit does not cause a complete sh utdown of the ic, but causes pulse output to be suspended; ther efore, the internal circuitry remains in operation. high speed ldo voltage regulator the voltage regulator block of the xc9510 series consists of a reference voltage source, error amplifier, and current limiter circuit.the voltage divided by split resistors is compar ed with the internal reference voltage by the error amplifier. the p-channel mosfet, which is connected to the vr out pin, is then driven by the subsequent output signal. the output voltage at the vr out pin is controlled and stabilized by a system of negative feedback. a stable output voltage is achievable even if used with low esr capacitors as a phase compensation circuit is built-in. the reference voltage source provides the reference volt age to ensure stable output voltage of the regulator. the error amplifier compares the reference voltage with the signal from vr out , and the amplifier controls the output o f the p-ch driver transistor. the voltage regulator block includes a co mbination of a constant cu rrent limiter circuit and a foldback circuit. when the load current reaches the current limit le vel, the current limiter circuit operates and the output voltage of the voltage regulator block drops. as a result of this drop in output voltage, the fold back circuit operates, output voltage drops further and the load current decreases. when the vr out and gnd pin are shor ted, the load current of about 30ma flows.
1363 x c9510 series operational explanation ( continued ) voltage detector the detector block of the xc9510 seri es detects output voltage from the vd out pin while sensing either v dd , dc out , o r vr out internally. (n-channel open drain type) < ce / mode pin function> the operation of the xc9510 series' dc/ dc converter block and voltage regulator block will enter into the shut down mode when a low level signal is input to the ce/mode pin. during the shut down mode, t he current consumption occurs only in the detector and is 3.0 a (typ.), with a state of high impedance at the lx pin and dc out pin. the ic starts its operation by inputting a high level signal or a middle level signal to the ce/mode pin. the input to the ce/mode pin is a cmos input and the sink current is 0 a (typ.). the operation of the xc9510d to f series' voltage detector block will enter into stand-by mode when a high level signal is input to the ce/mode pin. the voltage regulator block will operate when a middle level signal is input. but when a low level signal is input, the voltage regulator block will enter into stand-by mode. with the xc9510h to l series control can be pwm control when the ce/mode pin is 'm' level and pwm/pfm automatic switching control w hen the ce/mode pin is 'h' level. application information 1. the xc9510 series is designed for use with ceramic out put capacitors. if, however, the potential difference between dropout voltage or output curr ent is too large, a ceramic capacitor may fail to absorb the resulting high switching energy and oscillation could occur on the output. if the input-output potential difference is large, connect an electrolytic capacitor in parallel to compensate for insufficient capacitance. 2. spike noise and ripple voltage arise in a switching regulator as wi th a dc/dc converter. these are greatly influenced by extern al component selection, such as the coil inductance, capacitance va lues, and board layout of external components. once the design has been completed, verification wi th actual components should be done. 3. when the difference between v in and v out is large in pwm control, very narrow pulses will be outputted, and there is the possibility that some c ycles may be skipped completely. 4. when the difference between v in and v out is small, and the load current is heavy, very wide pulses will be outputted and there is the possibility that some cycles may be skipped completely: in this case, the lx pin may not go low at all. notes on use dc/dc waveform (3.3v, 1.2mhz) < external components> l:4.7 h(cdrh4d28c,sumida) cin:4.7 f(ceramic) cl:10 f(ceramic) < external components> l:4.7 h(cdrh4d28c,sumida) cin:4.7 f(ceramic) cl:10 f(ceramic)
1364 xc9510 series application information (continued) 5. the ic's dc/dc converter operates in synchronous m ode when the coil current is in a continuous state and non-synchronous mode when the coil current is in a discont inuous state. in order to maintain the load current value when synchronous switches to non-synchronous and vise versa, a ripple voltage may increase because of the repetition of switching between synchr onous and non-synchronous. when this state continues, the increase in the ripple voltage stops. to reduce the ripple voltage, plea se increase the load capacitance value or use a schottk y diode externally. when the current used becomes clos e to the value of the l oad current when synchronous switches to non- synchronous and vise versa, the swit ching current value can be changed by changing the coil inductance value. in case changes to coil inductance are to values other than the recommended coil inductance values, verification with actual components should be done. ics = (v in - dc out ) x onduty / (l x fosc) ics: switching current from synchronous rectification to non-sync hronous rectification onduty: onduty ratio of p-ch driver transistor ( . =.step down ratio : dc out / v in ) l: coil inductance value fosc: oscillation frequency id out : the dc/dc load current (the sum of the dc/dc's and the regulator 's load if the regulator has load.) 6. when the xc9510h to l series operates in pwm/pfm automatic switching control mode, the reverse current ma y become quite high around the load current value when sync hronous switches to non-synchronous and vise versa (also refer to no. 5 above). under this condition, switching synchronous rect ification and non-synchronous rectification may be repeated because of the reverse current, and the ripple voltage may be increased to 100mv o r more. the reverse current is the current that flows in t he pgnd direction through the n-ch driver transistor from the coil. the conditions which cause this operation are as follows. pfm duty < step down ratio = dc out / v in x 100 (%) pfm duty: 30% (typ.) please switch to pwm control via the mode function in cases where the load current value of the dc/dc converte r is close to synchronous . notes on use ( continued ) dc/dc waveform (1.8v, 600khz) @ vin=6.0v < external components> l:10 h(cdrh5d28c,sumida) cin:4.7 f(ceramic) cl:10 f(ceramic) step down ratio : 1.8v / 6.0v = 30%
1365 x c9510 series application information (continued) 7. with the dc/dc converter of the ic, the peak current of the coil is controlled by the current limit circuit. since the peak current increases when dropout voltag e or load current is high, current limit starts operating, and this can lead to instability. when peak current becomes high, please ad just the coil inductance value and fully check the circuit operation. in addition, please calculate the peak current according to the following formula: peak current: ipk = (v in - dc out ) x onduty / (2 x l x fosc) + id out 8. when the peak current, which exceeds limit current flows within the specified time, t he built-in driver transistor is turned off (the integral latch circuit). during the time until it detects limit current and before the built-in transisto r can be turned off, the current for limit cu rrent flows; therefore, care must be taken when selecting the rating for the coil or the schottky diode. 9. when vi n is low, limit current may not be reached because of voltage falls caused by on resistance or serial resistance of the coil. 10. in the integral latch circuit, latch time may become longer and latch operation may not work when v in is 3.0v o r more. 11. use of the ic at voltages below the recommended voltage range may lead to instability. 12. this ic and the external components should be used with in the stated absolute maximum ratings in order to prevent damage to the device. 13. since the dc/dc converter and the regula tor of the xc9510 series are connec ted in series, the sum of the outpu t current (id out ) of the dc/dc and the output current (ir out ) of the vr makes the current flows inside the dc/dc converter. please be careful of the power dissipation when in use. please calculate power dissipation by using the following formula. pd=pddc/dc + pdvr dc/dc power dissipation (when in synchronous operation) : pddc/dc = id out 2 x ron vr power dissipation: pdvr=(dc out ? vr out ) x ir out ron: on resistance of the built-in driver transistor to the dc/dc (= 0.5 ) ron=rpon x p-chonduty / 100 + rnon x (1 ? p-chonduty / 100) 14. the voltage detector circuit built-in t he xc9510 series internally monitor the v dd pin voltage, the dc/dc output pin voltage and vr output pin voltage. for the xc9510b/c/e/f /k/l series, which voltage detector circuit monitors the dc/dc output pin voltage and the vr out put pin voltage, please determine the detect voltage value (vdf) by the following equation. vdf Q (setting voltage on both the dc out voltage and the vr out voltage) 85%* * an assumed value of tolerance among the dc out voltage, the vr out voltage, and the vd release voltage (the vd detect voltage and hysteresis range). notes on use ( continued )
1366 xc9510 series instructions on pattern layout 1. in order to stabilize v in 's voltage level, we recommend that a by-pass capacitor (ci n ) be connected as close as possible to the v dd & agnd pins. this ic is the composite ic of the dc/dc converter and regulator. fluctuation o f the v in 's voltage level causes mutual interference. 2. please mount each external component as close to the ic as possible. 3. wire external components as close to the ic as possi ble and use thick, short connecting traces to reduce the circuit impedance. 4. make sure that the pcb gnd traces are as thick as possible, as variat ions in ground potential caused by high ground currents at the time of switching may result in instability of the dc/dc converter and have adverse influence on the regulator output. 5. if using a schottky diode, please connect the anode side to the agnd pin through c in . characteristic degradation caused by the noise may occur depending on the arrangement of the schottky diode. notes on use ( continued )
1367 x c9510 series typical performance characteristics (a) dc/dc converter (1) efficiency vs. output current
1368 xc9510 series typical performance characteristics (continued) (2) output voltage vs. output current (a) dc/dc converter (continued)
1369 x c9510 series typical performance characteristics (continued) (3) output voltage vs. ripple voltage (a) dc/dc converter (continued)
1370 xc9510 series typical performance characteristics (continued) (a) dc/dc converter (continued) (4) output voltage vs. ambient temperature (5) soft start time vs. ambient temperature
1371 x c9510 series typical performance characteristics (continued) (a) dc/dc converter (continued) (6) dc/dc supply current vs. ambient temperature(vr:shutdown)*
1372 xc9510 series typical performance characteristics (continued) (a) dc/dc converter (continued) (7) lx p-ch/n-ch on resistance vs. input voltage (8) oscillation frequency vs. ambient temperature (9) u.v.l.o. voltage vs. ambient temperature
1373 x c9510 series (10-2) dc/dc load transient response (*dcout:3.3v fosc:1.2mhz) (a) pwm control typical performance characteristics (continued) (b) pwm/pfm automatic switching control* (*xc9510h/k/l series only) (a) dc/dc converter (continued)
1374 xc9510 series (10-3) dc/dc load transient response (*dcout:1.8v fosc:600khz) (a) pwm control typical performance characteristics (continued) (b) pwm/pfm automatic switching control* (*xc9510h/k/l series only) (a) dc/dc converter (continued)
1375 x c9510 series (10-4) dc/dc load transient response (*dcout:3.3v fosc:600khz) (a) pwm control typical performance characteristics (continued) (a) dc/dc converter (continued) (b) pwm/pfm automatic switching control* (*xc9510h/k/l series only)
1376 xc9510 series typical performance characteristics (continued) (b) voltage regulator (1) output voltage vs . input voltage
1377 x c9510 series typical performance characteristics (continued) (b) voltage regulator (continued) (2) output voltage vs . output current (current limit)
1378 xc9510 series typical performance characteristics (continued) (b) voltage regulator (continued) (3) dropout voltage vs . output current
1379 x c9510 series typical performance characteristics (continued) (b) voltage regulator (continued) (4) output voltage vs . output current
1380 xc9510 series typical performance characteristics (continued) (b) voltage regulator (continued) (5) output voltage vs . ambient temperature
1381 x c9510 series typical performance characteristics (continued) (6) ripple rejection ratio vs . ripple frequency (b) voltage regulator (continued)
1382 xc9510 series (7) vr load transient response typical performance characteristics (continued) (b) voltage regulator (continued)
1383 x c9510 series typical performance characteristics (continued) (c) voltage detector (1) output current vs. input voltage (2) detect voltage vs. input voltage
1384 xc9510 series typical performance characteristics (continued) (c) voltage detector (continued) (3) detect voltage,release voltage vs. ambient temperature
1385 x c9510 series typical performance characteristics (continued) (d) common (1) supply current vs. ambient temperature (dc/dc & vr & vd) (2) shutdown current vs. input voltage (3) shutdown current vs. ambient temperature
1386 xc9510 series series type dc/dc control methods ce=?vceh? level ce=?vcem? level ce=?vcel? level vd sense pin a v dd b dc out c - - dc/dc: off vr: off vd: on vr out d v dd e dc out f pwm control dc/dc: on vr: off vd: on dc/dc: on vr: on vd: on dc/dc: off vr: off vd: on vr out h v dd k dc out xc9510 l pwm, pfm/pwm manual switch pfm / pwm automatic switch pwm control dc/dc: off vr: off vd: on vr out typical performance characteristics (continued) * control methods, ce/mode pin, vdsense pin (d) common (continued) (4) ce/mode pin threshold voltage* ambient temperature:ta( )

▲Up To Search▲

Price & Availability of XC9510BXXXSX

	To Download XC9510BXXXSX Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .