ts3410 1a / 1.4mhz synchronous buck converter 1/10 version: c08 sot - 25 general description ts3410 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. the device is available in an adjusta ble version. supply current with no load is 250ua a nd drops to <1ua in shutdown. the 2.5v to 6v input voltage rang e makes ts3410 ideally suited for single li-ion, tw o to four aa battery-powered applications. 100% duty cycle pr ovides low dropout operation, extending battery lif e in portable systems. pwm pulse skipping mode operation provides very low output ripple voltage for noise sensitive applications. switching frequency is internally set at 1.4mhz, allowing the use of small surface mount inductors and capacitors. the internal synchronous switch inc reases efficiency and decreases need of an external schottky diode. low output voltages are easily supported wit h the 0.6v feedback reference voltage. features high efficiency: up to 96% 2.5v to 6v input voltage range output voltage from 0.6v to vin short circuit protection (scp) build in soft-start function 1.4mhz constant frequency operation up to 1a output current low quiescent current: 250ua (typ.) no schottky diode required in application 1ua shutdown current current mode operation for excellent line and load transient response application cellular phones digital still cameras portable electronics usb devices pin description name description en power - off pin h normal operation l step-down operation stopped (all circuits deactivated) gnd ground pin sw switch output pin. connect external inductor here. minimize trace area at this pin to reduce emi. v cc ic power supply pin fb output feedback pin ordering information part no. package packing ts3410cx5 rf sot-25 3kpcs/ 7 reel application circuit v out = 0.6 * (1+r1/r2) r2 300k c1 4.7u c2 10u v out =1.8v r2=100k~330k l1 2.7uh r1 600k u1 ax3513 vin en gnd sw fb c3 15p v in =2.5v~6v pin definition : 1. en 2. ground 3. switching output 4. input 5. feedback
ts3410 1a / 1.4mhz synchronous buck converter 2/10 version: c08 absolute maximum rating characteristics symbol rating unit v in pin voltage v in gnd - 0.3 to gnd + 6.5 v feedback pin voltage v fb gnd - 0.3 to v in + 0.3 v run pin voltage v run gnd - 0.3 to v in + 0.3 v switch pin voltage v sw gnd - 0.3 to v in + 0.3 v peak sw sink & source current i psw 1.4 a power dissipation p d (t j -t a ) / ja mw storage temperature range t st -40 to +150 o c operating temperature range t op -40 to +85 o c junction temperature t j +125 o c thermal resistance from junction to case jc 110 o c/w thermal resistance from junction to ambient ja 250 o c/w note1: ja is measured with the pcb copper area of approximat ely 1 in 2 (multi-layer). that need connect to gnd pin of the ts3410. electrical specifications (ta = 25 o c, v in =v run =3.6v unless otherwise noted) characteristics symbol conditions min typ max units feedback voltage v fb t a =25 ,i out =50ma 0.588 0.6 0.612 v -40c t a 85c 0.582 0.6 0.618 quiescent current i ccq v fb =0.5v -- 250 350 ua feedback bias current i fb v fb =0.65v -- -- 30 na shutdown supply current i sd v run =0v -- 0.1 1 ua maximum output current i out(max) v cc =3v, v out =1.8v 1 -- -- a current limit i limit v cc =3v 1.2 1.4 -- a line regulation v out /v out v cc = 2.5v~5.5v -- 0.04 0.4 % load regulation v out /v out i out = 0.01 to 0.6a -- 0.5 -- % oscillation frequency f osc sw pin 1.1 1.4 1.7 mhz r ds(on) of p-ch mosfet r dson i sw = 500ma -- 0.3 0.4 r ds(on) of n-ch mosfet r dson note 1 -- 0.25 0.35 efficiency e ffi v out =3.3v,i out = 0.5a -- 94 -- % en pin logic input threshold voltage v enl -- -- 0.4 v v enh 1.5 -- --. en pin input current i en -- 0.1 1 ua thermal shutdown t ds -- 140 -- c thermal shutdown hysteresis t sh -- 30 -- c note 1: guaranteed by design note 2: 100% production test at +25c. specifications over the temperature range are guaranteed by design and characterization.
ts3410 1a / 1.4mhz synchronous buck converter 3/10 version: c08 block diagram fb en vin sw gnd over-temperature and short-circuit protection ref soft-star 0.6v + - - + icomp - + isense amp osc slope comp pwm logic - + izero comp non-overlap control reset set enable logic function description operation ts3410 is a monolithic switching mode step-down dc- dc converter. it utilizes internal mosfets to achie ve high efficiency and can generate very low output voltage by using internal reference at 0.6v. it operates a t a fixed switching frequency, and uses the slope compensated current mode architecture. this step-down dc-dc converter supplies minimum 1000ma output current at input voltage range from 2.5v to 5.5v. current mode pwm control slope compensated current mode pwm control provides stable switching and cycle-by-cycle current limit for excellent load and line transient responses and pro tection of the internal main switch (p-ch mosfet) a nd synchronous rectifier (n-ch mosfet). during normal operation, the internal p-ch mosfet is turned on fo r a certain time to ramp the inductor current at each r ising edge of the internal oscillator, and switched off when the peak inductor current is above the error voltage. the current comparator, icomp, limits the peak indu ctor current. when the main switch is off, the synchronous rectif ier will be turned on immediately and stay on until either the inductor current starts to reverse, as indicated by the current reversal comparator, izero, or the beg inning of the next clock cycle..
ts3410 1a / 1.4mhz synchronous buck converter 4/10 version: c08 application information setting the output voltage application circuit item shows the basic applicatio n circuit with ts3410 adjustable output version. th e external resistor sets the output voltage according to the f ollowing formula: inductor selection for most designs, the ts3410 operates with inductor s of 2.2h to 3.3h. low inductance values are phys ically smaller but require faster switching, which results in some efficiency loss. the inductor value can be derived from the following formula: where is inductor ripple current. large value induc tors lower ripple current and small value inductors result in high ripple currents. choose inductor ripple current app roximately 20% of the maximum load current 1a, ? il=200ma. for output voltages above 2.0v, when light-load eff iciency is important, the minimum recommended induc tor is 2.7h. for optimum voltage-positioning load transie nts, choose an inductor with dc series resistance i n the 50m to 150m range. for higher efficiency at heavy loads (above 200ma), or minimal load regulation (but some transient overshoot), the resistance should be kept below 100m . the dc current rating of the inductor should be at least equal to the maximum load current plus hal f the ripple current to prevent core saturation (10 00ma+100ma) input capacitor selection the input capacitor reduces the surge current drawn from the input and switching noise from the device . the input capacitor impedance at the switching frequency shal l be less than input source impedance to prevent hi gh frequency switching current passing to the input. a low esr input capacitor sized for maximum rms curr ent must be used. ceramic capacitors with x5r or x7r dielect rics are highly recommended because of their low es r and small temperature coefficients. a 4.7f ceramic cap acitor for most applications is sufficient. output capacitor selection the output capacitor is required to keep the output voltage ripple small and to ensure regulation loop stability. the output capacitor must have low impedance at the swi tching frequency. ceramic capacitors with x5r or x7 r dielectrics are recommended due to their low esr an d high ripple current. compensation capacitor selection the compensation capacitors for increasing phase ma rgin provide additional stability. it is required a nd more than 15pf. please refer to demo board schematic for desi gn. table 1: resistor select for output voltage setting vout r2 r1 1.2v 300k 300k 1.5v 300k 450k 1.8v 300k 600k 2.5v 150k 470k 3.3v 120k 540k 5v 124k 910k table 2: inductor select for output voltage setting (v in =3.6v) vout 1.2v 1.5v 1.8v 2.5v inductor 2.7uh 2.7uh 2.7uh 2.2uh part number we-tpc 7440430027 7440430027 7440430027 7440430022 note: part type mh or m (www.we - online.com)
ts3410 1a / 1.4mhz synchronous buck converter 5/10 version: c08 electrical characteristics curve figure 1. output voltage vs. input voltage figure 2. current limit vs. input voltage figure 3. quiescent current vs. input voltage figure 4. threshold voltage vs. input voltage figure 5. output voltage vs. temperature figure 6. quiescent current vs. temperature
ts3410 1a / 1.4mhz synchronous buck converter 6/10 version: c08 electrical characteristics curve figure 7. frequency vs. temperature figure 8. efficiency vs. output current figure 9. efficiency vs. output current figure 10. power-on waveform figure 11. power-on waveform figure 12. enable-on waveform
ts3410 1a / 1.4mhz synchronous buck converter 7/10 version: c08 electrical characteristics curve figure 13. enable-on waveform figure 14. load transient figure 15. load transient figure 16. tsd to release figure 17. tsd to release
ts3410 1a / 1.4mhz synchronous buck converter 8/10 version: c08 application information (continue) layout guide
ts3410 1a / 1.4mhz synchronous buck converter 9/10 version: c08 sot-25 mechanical drawing arking diagram g6 = device code y = year code a = 2010 1 = 2011 w = week code 01 ~ 26 (a~z) 27 ~ 52 (a~z) x = internal id code sot-25 dimension dim millimeters inches min max min max. a+a1 0.09 1.25 0.0354 0.0492 b 0.30 0.50 0.0118 0.0197 c 0.09 0.25 0.0035 0.0098 d 2.70 3.10 0.1063 0.1220 e 1.40 1.80 0.0551 0.0709 e 1.90 bsc 0.0748 bsc h 2.40 3.00 0.09449 0.1181 l 0.35 bsc 0.0138 bsc ? 1 0o 10o 0o 10o s1 0.95 bsc 0.0374 bsc
ts3410 1a / 1.4mhz synchronous buck converter 10/10 version: c08 notice specifications of the products displayed herein are subject to change without notice. tsc or anyone on its behalf, assumes no responsibility or liability for any erro rs or inaccuracies. information contained herein is intended to provide a product description only. no license, express or implied, to any intellectual property rights is granted by this document. except as provided in tscs terms and co nditions of sale for such products, tsc assumes no liability wh atsoever, and disclaims any express or implied warr anty, relating to sale and/or use of tsc products includi ng liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, cop yright, or other intellectual property right. the products shown herein are not designed for use in medical, life-saving, or life-sustaining applica tions. customers using or selling these products for use i n such applications do so at their own risk and agr ee to fully indemnify tsc for any damages resulting from such i mproper use or sale.
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