AIC3414 1.2mhz, synchronous step-up converter in sot23-6 analog integrations corporation si-soft research center ds-3414g-01 20091118 3a1, no.1, li-hsin rd. i, science park, hsinchu 300, taiwan, r.o.c. tel: 886-3-5772500, fax: 886-3-5772510 www.analog.com.tw 1 ? features z output voltage range: 2.5v to 4.0v z synchronous 92% effici ent boost converter z 1.2 mhz fixed switching frequency z built-in current mode compensation z built-in protection: over current protection and over temperature protection. z quiescent current:300 a at v in =1.1v, v out =3.3v, i out =0a z <1 a shutdown standby current z emi reduction anti-ringing control circuitry z thin sot23-6 package ? applications z single / dual cells ni-cd / ni-mh type battery operated products z internet audio player z wireless and dsl modems z digital still cameras z portable equipment ? description the AIC3414 step-up converter is based on a fixed frequency, pulse-width-modulation (pwm) controller using an internal synchr onous rectifier to obtain maximum efficiency. it stays in operation with supply voltages down to 0.5v. the AIC3414 provides a complete power supply solution for products po- wered by either one or two alkaline, ni-cd, or ni-mh battery cells. the AIC3414 output voltage can be adjustable up to 4.0v. at light load condition, the AIC3414 can work at psm mode to improve effi- ciency and reduce quiescent current. the AIC3414 includes the anti-ringing circuitry. the anti-ringing circuitry is implemented to reduce ringing and in effect lower radiated electromagnetic energy when the converter enters the discontinuous con- duction mode. ? typical application circuits 4.7uf cin 4.7uf cout 1m r1 600k r2 4.7uh l1 sw 1 vin 6 vout 5 shdn 4 fb 3 gnd 2 AIC3414 u1 vout 1.2v vi n 3.3v/120ma
AIC3414 2 ? ordering information example: aic 3414gg6tr ? in sot-23-6 green package & taping & r eel packing type packing type tr: tape & reel bg: bag package type g6: sot-23-6 g: green package a ic3414x xx x x pin configuration sot-23-6 top view note: pin1 is determi ned by orienting the package marking as shown. z marking part no. marking AIC3414gg6 3414g ? absolute maximum ratings input voltage 6v shdn pin voltage 6v sw and fb pin voltage 6v operating temperature range -40 c to 85 c maximum junction temperature 150 c storage temperature range -65 c to 150 c lead temperature (soldering 10 sec.) 260 c thermal resistance (junction to case) 115 c/w thermal resistance (junction to ambient) 250 c/w (assume no ambient airflow, no heatsink) absolute maximum ratings are those values beyond which the life of a device may be impaired.
AIC3414 3 ? electrical characteristics (t a =25 c, vin=1.2v, vout=3.3v, unless otherwise specified.) (note1) parameter test condition symbol min typ max unit output voltage range v out 2.5 4.0 v minimum start up voltage i out =1ma 0.9 1.1 v minimum operation voltage shdn=v in 0.5 v quiescent current v fb =1.4v i q 300 500 a shut down current (oscillator no switching) shdn= 0v, v in =1.1v, v out =3.3v i sd 0.1 1 a line regulation v in =1.5~2.5v, v out =3.3v, i out =1ma 10 mv/v load regulation vin=2.5v, v out =3.3v, i out =1~100ma 0.25 mv/ ma feedback voltage v fb 1.192 1.23 1.268 v fb input leakage current v fb =1.25v i fb 0.1 a maximum duty cycle (pwm) measurement on the lx duty 80 88 % oscillator frequency (pwm) f 950 1200 1500 khz nmos switch leakage v lx =3.6v 0.1 5 a nmos switch on resistance v out = 3.3v 0.35 pmos switch on resistance v out = 3.3v 0.45 shdn high threshold voltage v shdn,h 0.8 v shdn low threshold voltage v shdn,l 0.35 v shdn input current shdn= 5.5v i shdn 0.01 2 a current limit setting v out =3.3v, measure n-mos current i ocp 0.85 a over temperature protection 140 c over temperature hysteresis 10 c note 1: specifications are production tested at t a =25c. specifications over the -40c to 85c operating temperature range are assured by design, characte rization and correlation with statistical quality controls (sqc).
AIC3414 4 ? typical performance characteristics fig. 1 efficiency vs. output current fig. 2 frequency vs. temperature fig. 3 maximum output current vs. temperature fig. 4 output voltage vs. output current fig. 5 output voltage vs. temperature fig. 6 minimum start-up voltage vs. output current v out =3.3v v out =3.3v, v in =1.2v, i out =2ma v out =3.3v v in =1.2v, i out =10ma v out =3.3v
AIC3414 5 ? typical performance characteristics (continued) fig. 7 feedback voltage vs. temperature fig.8 frequency vs. vs. supply voltage fig. 9 maximum output current vs. supply voltage fig. 10 quiescent current vs. supply voltage fig. 11 quiescent current vs. supply voltage fig. 12 nmos r ds (on) vs. supply voltage v out =3.3v, i out =0ma v out =3.3v v out =3.3v, i out =0ma
AIC3414 6 ? typical performance characteristics (continued) fig. 13 ripple voltage vs. output current fig.14 start-up voltage waveform fig.15 anti-ringing operation (i out =10ma) fig. 16 ccm switch waveform (i out =50ma) fig. 17 load transient response sw output ripple i l output ripple sw i l v in =1.2v,v out =3.3v v in =1.2v,v out =3.3v v in =1.5v,v out =3.3v, i out =40m~100ma output ripple i out v out sw i l v in =1.3v,v out =3.3v, i out =10ma v out =3.3v
AIC3414 7 ? block diagram ? pin descriptions pin 1: sw - power switch pin. connect inductor between sw and vin pin 2: gnd - i/o control/logic ground. pin 3: fb - boost-voltage feedback of adjusta- ble version, the feedback reference voltage is typically 1.23v pin 4: shdn - shutdow n signal input. logic high enables the ic. logic low disables the ic. shutdown current is <1 a. pin 5: vout- power output pin. connected to the positive terminal of the output capacitor and to the external resis- tor divider. pin 6: vin - power supply input. must be closely decoupled to gnd, pin 2, with a 4.7 f or greater ceramic capacitor. pwm control antiringring control 1.2v ref vin mux start-up oscillator current sense slope compensation 2.3v 1.2mhz oscillator shutdown control vin sw fb vout gnd shdn r c c c c
AIC3414 8 ? application information the AIC3414 is a synchr onous step-up dc-dc con- verter. it is based on a slope compensated current mode pwm control topology. it operates at a fixed frequency of 1.2mhz. at the beginning of each clock cycle, the main switch (nmos) is turned on and the inductor current starts to ramp. after the maximum du- ty cycle or the sense current signal equals the error amplifier (ea) output, the main switch is turned off and the synchronous switch (pmos) is turned on. the de- vice can operate with an input voltage below 1v; the typical start-up voltage is 0.9v. current limit the over current protection is to limit the switch current. the output voltage will be dropped when over current is happened. the current limi t amplifier will shut the n-mos switch off once the current exceeds its thre- shold. the current amplifier delay to output is about 50 ns. anti-ringing control an anti-ringing circuitry is included to remove the high frequency ringing that app ears on the sw pin when the inductor current goes to zero. in this case, a ringing on the sw pin is induced due to remaining energy stored in parasitic components of switch and inductor. the anti-ringing circuitry clamps the voltage internally to the battery voltage and therefore dampens this ringing. zero current comparator the zero current comparator monitors the inductor current to the output and shuts off the synchronous rectifier once the current is below 20 ma, this prevents the inductor current from reversing in polarity improv- ing efficiency at light loads. device shutdown when shdn is set logic high, the AIC3414 is put into active mode operation. if shdn is set logic low, the device is put into shutdown mode and consumes less than 1 a of current. after start-up, the internal circuitry is supplied by vout, however, if shutdown mode is enabled, the internal circuitry will be supplied by the input source again. adjustable output voltage an external resistor divider is used to set the output voltage. the output voltage of the switching regulator (v out ) is determined by the following equation: ? ? ? ? ? ? ? ? + = 2 1 fb out r r 1 v v where v fb is 1.23v reference voltage. input inductor selection the inductor value determines the ripple current. the approximate ripple current and inductance value are measured by the following equations: sw in l lf d v i = where l i = inductor ripple current f sw = switch frequency d = duty cycle, (v out - v in )/ v out increasing the value of indu ctance will reduce the out- put ripple current and ripple voltage. input capacitor selection surfaces mount 4.7 f or greater, x5r or x7r, ceramic capacitor is suggested for the input capacitor. the in- put capacitor provides a low impedance loop for the edges of pulsed current draw n by the AIC3414. low
AIC3414 9 esr/esl x7r and x5r ceramic capacitors are ideal for this function. to minimize stray inductance, the ca- pacitor should be placed as close as possible to the ic. this keeps the high frequency content of the input current localized, minimizing emi and input voltage ripple. always examine the ceramic capacitor dc vol- tage coefficient characteristics to get the proper value. output capacitor selection the output capacitor limits the output ripple and pro- vides holdup during large load transitions. a 4.7 f to 10 f, x5r or x7r, ceramic capacitor is suggested for the output capacitor. typically the recommended ca- pacitor range provides sufficient bulk capacitance to stabilize the output voltage during large load transitions and has the low esr and esl characteristics neces- sary for low output voltage ripple. pcb layout guidance the AIC3414 typically operates at 1.2mhz. this is a considerably high frequency for dc-dc converters. pcb layout is important to guarantee satisfactory per- formance. it is recommended to make traces of the power loop, especially where the switching node is involved, as short and wide as possible. first of all, the inductor, input and output capacitor should be as close as possible to the device. feedback and shutdown circuits should avoid the pr oximity of large ac signals involving the power inductor and switching node. ? application circuits 4.7uf cin 10uf cout 1m r1 600k r2 4.7uh l1 c1 *ss0540 d1 sw 1 vin 6 vout 5 shdn 4 fb 3 gnd 2 AIC3414 u1 rs cs vout sw1 vi n *note: efficiency can boost if d1 is connected. r s and c s will reduce spike of circuit fig.11 AIC3414 application circuit.
AIC3414 10 ? physical dimensions z sot-26 note : information provided by aic is believed to be accurate and reli able. however, we cannot assume responsibility for use of any circuitry other than circuitry entirely em bodied in an aic product; nor for any infringement of patents or other rights of thir d par- ties that may result from its use. we reserve the right to change the circuitry and specifications without notice. life support policy: aic does not authorize any aic product for us e in life support devices and/or systems. life support device s or systems are devices or systems which, (i) are intended for surg ical implant into the body or (ii) support or sustain life, a nd whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonabl y expected to result in a significant injury to the user. c a a2 b with plating view b l1 l seating plane gauge plane 0.25 a1 section a-a base metal e1 d e aa e1 see view b e 0 0.90 0.30 1.50 2.60 2.80 0.08 0.30 0.05 e l1 l e1 c e e1 d b a2 a1 0.95 bsc 8 0.60 1.90 bsc 0.60 ref 1.30 1.70 3.00 3.00 0.22 0.50 0.15 0.95 min. s y m b o l a1.45 max. sot-26 millimeters note: 1.refer to jedec mo-178ab. 2.dimension d and e1 do not include mold flash, protrusions or gate burrs. mold flash, protrusion or gate burrs shall not exceed 10 mil per side. 3.controlling dimension is millimet er; converted inch dimensions are not necessarily exact.
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