SC2542

SC2542 SEMTECH | Alldatasheet

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1 www.semtech.com SC2542 High Performance Wide Input Range Dual Synchronous Buck Controller POWER MANAGEMENT Revision: August 24, 2005 Description Features

Applications

Typical Application Circuit ‹ Independent dual-switcher-outputs ‹ Integrated 5V standby output with over 50mA capability ‹ Wide input voltage range: 6.5V ~ 28V ‹ Adjustable output voltage down to 0.75V ‹ Light load efficiency enhancement ‹ Programmable skip mode operation ‹ Flexible power sequencing with enable and power good output ‹ Synchronous buck topology with voltage mode control ‹ Out of phase operation to reduce cost of input capacitor ‹ 10V internal regulator for gate driver to deliver high efficiency ‹ Programmable switching frequency: 100KHz ~ 300KHz ‹ Full protection: UVLO, OVP, and programmable OCP ‹ No need for current sense resistor ‹ Low standby operating current (200 µA typical) ‹ Low shut down current (100nA typical) ‹ 28 lead TSSOP package with exposed die pad (EDP) ‹ Fully WEEE package and RoHS Compliant SC2542 is a high performance dual PWM controller. It is designed to convert a widely ranged battery rail down to two independent output rails. The PWM operation of the two channels are 180 degrees out of phase which can greatly reduce the size and the cost of the input capaci- tors. Synchronous buck PWM topology and voltage mode control allow fast transient response and flexible com- ponent selection for easy designs. A 5V standby regula- tor is integrated. A 10V internal linear regulator provides the bias for the controller, and this voltage is optimized for gate drivers to deliver high efficiency. The light load efficiency can be greatly improved by turn- ing off the low side MOSFET upon reversal of inductor current. There is no need for a current sensing resistor because the MOSFET on resistance is used as the sens- ing element. Under extreme light load conditions, the device will operate in a pulse skip mode. The switching frequency can be dropped significantly to a level pro- grammed by external resistors. The battery energy is bet- ter utilized with these efficiency enhancement schemes. The power sequencing is fully supported including inde- pendent start up and power good output. In shutdown mode the controller only draws 100nA from the supply. The controller also offers full protection features for the conditions of under voltage, over voltage, and over cur- rent. The switching frequency is adjustable from 100KHz to 300KHz. TSSOP-28-EDP package is offered. ‹ Notebook computer system power ‹ Systems with 6.5V ~ 28V input ‹ Network and telecom systems ‹ Other portable devices VCC FB2 STBY MODE FB1 FB1 VO1 ENABLE PWGRD VCC 5VSBY VO2 (5V/10A) VIN+ VIN+VIN+ FB2 VO1 (3.3V/10A) TH-PAD SC2542 12 17 14 15 VIN VCC EN STBY FB1 ERROUT1 MI NSET1 SS1 ILIM1 BST1 DRVH1 PHASE1 PHASE2 DRVH2 BST2 ILIM2 SS2 MINSET2 ERROUT2 FB2 PWRGD ROSC 5VSBY AGND DRVL1 PGND PVCC DRVL2

2© 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Absolute Maximum Ratings

Electrical Characteristics

retemaraPs noitidnoCtseTn iMp yTx aMt inU tuokcoLegatlovrednU dlohserhTtratSg nisirCCV5 2.55 .55 7.5V siseretsyHOLVUs iseretsyh0 04V m ylppuSrewoP I(tnerruCgnitarepO NI I- CCVP )F ,hgih=NE,2SS/1SS S zHK002=7 2 1A m tnerruCgnitarepOCCVPF S GBdnaGTnoFn1,zHK002=4 1A m detalugeRCCVV NI V21>0 1V noitalugeRdaoLCCVA m02ot0tnerrucdaoL2 % tnerruCylppuSybdnatSe domYBTS0 020 53A µ tnerruCylppuSnwodtuhSe domnwodtuhS1 .00 1A µ Unless specified: TA = 25°C, VIN = 16V, FS = 200KHz. Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of th e parameters specified in the Electrical Characteristics section is not implied. retemaraPl obmySm umixaMs tinU DNGPot2TSB,1TSBV TSB 83V DNGPotNIVV NI 82V DNGPot2MILIdna1MILI NIVV DNGPotCCVPdnaCCV 41V DNGAotDNGP 3.0±V ,2HPot2TSB,1HPot1TSB 2HPot2HVRD,1HPot1HVRD 41ot3.0-V DNGPot2LVRD,1LVRD CCVot3.0-V DNGPotNE NIVot3.0-V DNGAotsniprehtollA CCVot3.0-V egnaRerutarepmeTnoitcnuJgnitarepOT J 051+ot04-C ° egnaRerutarepmeTegarotST GTS 051+ot06-C ° esaCotnoitcnuJ,ecnatsiseRlamrehT θ CJ 3W /C° tneibmAotnoitcnuJ,ecnatsiseRlamrehT θ AJ 53W /C° .ceS01)gniredloS(erutarepmeTdaeLT REDLOS 062C ° egatlovkaep)Sn001(eslupDNGAotESAHP 3-V egatlovkaep)Sn001(eslupDNGAotLVRD 3-V Note: (1) This device is ESD sensitive. Use of standard ESD handling precautions is required.

3 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Electrical Characteristics (Cont.) retemaraPs noitidnoCtseTn iMp yTx aMt inU ).tnoC(ylppuSrewoP noitalugeRYBSV5A m05<tnerrucdaol<A05 8.455 1.5V noitalugeReniLYBSV5V NI V82~V21=1 % dlohserhTtimiLtnerruCYBSV5 001A m ecnaticapaCtuptuOYBSV5muminiMA m05<tnerrucdaol<A01 F µ tuptuOrehctiwSniaM noitalugeReniLV 82<NIV<V75 .0% noitalugeRdaoLT ESNIM,A01<tnerrucdaol<A0 taolfnip 5.0% ycaruccAegatloVtuptuO, noitaunettakcabdeeftuohtiW TA Cº58+otCº04-= 537.00 57.05 67.0V ELBANE egatloVdlohserhThgiHNE 2V egatloVdlohserhTwoLNE 6.0V YBTS egatloVdlohserhThgiHYBTS 2V egatloVdlohserhTwoLYBTS 6.0V tratStfoS tnerruCegrahCtratStfoS 58A µ tnerruCegrahcsiDtratStfoS 51A µ LVRDrofegatloVdlohserhTelbasiD etats-irTfotuO NOgninrut,levelsihtwoleblluP )TEFediswolNOnruT(LVRD 56.0V reifilpmArorrE ecnerefeRkcabdeeFegatloVT A Cº58+otCº04-=5 37.00 57.05 67.0V )ecruoS(tnerruCsaiBtupnI 2A µ niaGpooLnepO )1( 07B d htdiwdnaBniaGytinU )1( 3z HM tnerruCkniS/ecruoStuptuO 1A m etaRwelS )1( gnidaoleviticapacFp0010 1S µ/V yaleDtuptuOotrotarapmoCMWP )1( 57S n Unless specified: TA = 25°C, VIN = 16V, FS = 200KHz.

4 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Electrical Characteristics (Cont.) retemaraPs noitidnoCtseTn iMp yTx aMs tinU rotallicsO esahPrepegnaRycneuqerF 0010 03z HK esahPrepycneuqerFrotallicsOR CSO K37= Ω 5710 125 42z HK emiTFFOmuminiM 0030 04S n egatloVkaePpmaRrotallicsO 0.3V egatloVyellaVpmaRrotallicsO 1V timiLtnerruC tnerruCecruoSMILI 90 11 1A µ egatloVtesffOMILI 2V m TESNIM teShtdiWesluPmuminiMV NI K701=R,V61= Ω 1S µ teShtdiWesluPmuminiMV NI K701=R,V8= Ω 2S µ teShtdiWesluPmuminiMV NI K35=R,V61= Ω 005S n elcyCytuD elcyCytuDmumixaM2&1MWPR CSO k37= Ω 09% elcyCytuDmuminiM2&1MWPR CSO k37= Ω 0% revirD )ecruoS(evirDetaGediShgiHk niS/ecruoS5 .0A )ecruoS(evirDetaGediSwoLk niS/ecruoS5 .0A emiTesiRevirDetaGC TUO Fp0001=0 3S n emiTllaFevirDetaGC TUO Fp0001=0 3S n emiTdaeD 08S n PVO egatloVdlohserhTPVOe gatlovkcabdeeF9 8.0V dooGrewoP egatloVdlohserhTg nisir2BF&1BF5 76.0V egatloVdlohserhTg nillaf2BF&1BF7 5.0V ytilibapaCkniSdooGrewoPA m1kniS4 .0V Unless specified: TA = 25°C, VIN = 16V, FS = 200KHz.

5© 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Pin Configuration Ordering Information rebmuNtraPe gakcaP )1( T(egnaR.pmeT A) TRTET2452CS )2( PDE-82-POSST5 8+ot04- BVE2452CSd raoBnoitaulavE Notes: (1) Only available in tape and reel packaging. A reel contains 2500 devices. (2) Lead free product. This product is fully WEEE and RoHS compliant. Marking Information yyww = Date Code (Example: 0012) xxxxx = Semtech Lot No. (Example: P94A01) (TOP VIEW) SC2542TE yyww xxxxxx SC2542TE yyww xxxxxx AGNDVIN TOP VIEW (28 Pin TSSOP-EDP) 5VSBYVCC ROSCEN PWRGDSTBY FB2FB1 ERROUT2ERROUT1 MINSET2MINSET1 SS2SS1 ILIM2ILIM1 BST2BST1 DRVH2DRVH1 PHASE2PHASE1 DRVL2DRVL1 PVCCPGND AGNDVIN TOP VIEW (28 Pin TSSOP-EDP) 5VSBYVCC ROSCEN PWRGDSTBY FB2FB1 ERROUT2ERROUT1 MINSET2MINSET1 SS2SS1 ILIM2ILIM1 BST2BST1 DRVH2DRVH1 PHASE2PHASE1 DRVL2DRVL1 PVCCPGND

6 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Pin Descriptions #niPe maNniPn oitcnuFniP 1N IV. V82otV5.6morfsiegnarehT.egatlovylppustupnI 2C CV .srevirdetagdnasaibpihcrofegatlovylppuS.tuptuorotalugerV01 3E LBANE tnerrucnwodtihslacipyT.delbasiderastuptuolla,wolsiELBANEnehT.levelelbitapmocLTT .An001si 4Y BTS siYBSV5ylnO.delbasiderastuptuorehctiwshtobdnarotalugerV01ehtwoldellupnehW .Aµ002yllacipytsitnerructnecseiuQ.elbaliava 51 BF. 1tuptuorofreifilpmarorreehtfotupnievitageN 61 TUORRE. 1retrevnockcubroftuptuoreifilpmarorrE

71 TESNIM nihtdiweslupmuminimehttesotDNGAotnipsihtmorfrotsiserlanretxetcennoC

.daolnevigarofedompiksniycneuqerfgnitarepoehtstesoslasihT.edomsuounitnocsid 81 SS elbasiD.emittrats-tfosehtstesDNGAotnipsihtmorfdetcennocroticapaclanretxenA .V56.0wolebnipsihtgnillupyb1tuptuo

91 MILI pirtnwodtuhstnerrucrevoehtstes1ESAHPotnipsihtmorfdetcennocrotsiserlanretxenA

.tniop 011 TSB roticapaclanretxenatcennoC.evirdetagedishgih1TUPTUOrofnoitcennocroticapactsooB .tiucriCnoitacilppAlacipyTehtninwohssa 111 HVRD .2HVRDhtiwesahpfotuoeerged081.1TUPTUOfoTEFSOMedishgihehtrofevirdetaG 211 ESAHP. 1tuptuorofedonesahP 311 LVRD. 1tuptuorofevirdetagediswoL 41D NGP. srevirdedis-wolfodnuorgrewoP 51C CVP. srevirdetagedis-wolrofegatlovylppuS 612 LVRD. 2tuptuorofevirdetagedis-woL 712 ESAHP. 2tuptuorofedonesahP 812 HVRD .1HVRDGhtiwesahpfptuoeerged081.2TUPTUOfoTEFSOMedishgihehtrofevirdetaG 912 TSB lanretxenatcennoC.evirdetagedishgih2TUPTUOehtrofnoitcennocroticapactsooB .tiucriCnoitacilppAlacipyTehtninwohssasroticapac

022 MILI pirtnwodtuhstnerrucrevoehtstes2ESAHPotnipsihtmorfdetcennocrotsiserlanretxenA

.tniop 122 SS tuptuoelbasiD.emittrats-tfosehtstesDNGAotnipsihtmorfdetcennocroticapaclanretxenA .V56.0wolebnipsihtgnillupyb2

222 TESNIM nihtdiweslupmuminimehttesotDNGAotnipsihtmorfrotsiserlanretxeenotcennoC

.daolnevigarofedompiksniycneuqerfgnitarepoehtstesoslasihT.edomsuounitnocsid 322 TUORRE. 2retrevnockcubroftuptuoreifilpmarorrE 422 BF. 2tuptuorofreifilpmarorreehtfotupnievitageN

7 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Pin Descriptions (Cont.) #niPe maNniPn oitcnuFniP 52D GRWP .leveldlohserhtdoogrewopehtwolebsituptuorehgienehwwolslluP.tuptuorotcellocnepO 62C SOR .ycneuqerfrotallicsostesDNGAotnipsihtmorfdetcennocrotsiserlanretxenA 72Y BSV5. woldellupsiELBANEnehwdelbasiD.tuptuorotalugerV5 82D NGA. dnuorglangisgolanA -L AMREHT DAP detcennoctoN.saivelpitlumgnisuenalpdnuorgottcennoC.sesoprupgniknistaehrofdaP .yllanretni

8© 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Block Diagram (Only Channel-1 shown) 5VSBY Oscillator Ramp generator SS1 FB1 BST1 DRVH1 10V FB2 LDO FB1 PVCC Minumin DRVL1 VIN FB1 OVP 0.75V OUT PHASE1 Pulse VCC OUT- 0.75V PVCC Ramp1 OVP Generator EN 0.89V VCC VCC OUT ERROUT1 R S/ Q OUT PVCC CLK1 STBY Skip VCC FB1 ON/OFF PWRGD 0.65V Mode Protect 1 UVLO ROSC STBY dector UVLO 10u A E/A OUT Protect 1 Protect 1 PHASE1 AGND Band VCC Band ENABLE ILIM1 Gap 2 PWM OUT S R Q Gap 1 MINSET1 3R R OCP 85uA 0.675V 15uA OCP LDO 0.75V

hysteresis voltage for the UVLO ramp down threshold. ate in skip mode and improves the light load efficiency. Setting Tpulse is 80% of normal pulse wide. pin does not sink more than 1mA when PWRGD is low. Figure 10. Block diagram of the control loop. internal ramp, and R is the equivalent load.

swing) and the winding AC resistance losses are higher. the rated output load current. KHz but with attendant higher core losses. Figure 13. An equivalent circuit of output. and Co on the output voltage. The first term is the DC voltage across Co at time t = 0.

solid OS-CON, POSCAP, and tantalum. capacitors are used, the current ratio increases to 8.3. pacitors will then determine the output ripple-voltage. should be calculated using the following formula. Figure 14. Equivalent RC branch.

Channel 2 be D1, D2 and Io1, Io2, respectively.

201 Rds

Figure 16. Figure of Merit curves. The closer the curve is to the origin, the lower is the FOM. Rds(on)and Cg has to be made. MOSFET with low Rds(on) are used for the bottom switch. c) the gate loss due to the gate resistance RG.

Rds(on) varies with temperature and gate-source voltage. Ω when Vgs is greater than 10V. perature increases from 25°C to 110°C. Figure 17. MOSFET switching characteristics capacitance when Vds is falling. Switching losses occur during the time interval [t1, t3]. Vgsp is the Miller plateau voltage shown in Figure17. cases. The worst case is then used for thermal design.

20© 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT 2, ( )bc Q RMS DS ONPI R= where Rds(on) is the channel resistance of bottom MOS- FET. If the input voltage to output voltage ratio is high (e.g. Vin = 12V, Vo = 1.5V), the duty ratio D will be small. Since the bottom switch conducts with duty ratio (1-D), the corresponding conduction losses can be quite high. Due to non-overlapping conduction between the top and the bottom MOSFET, the internal body diode or the ex- ternal Schottky diode across the drain and source termi- nals always conducts prior to the turn on of the bottom MOSFET. The bottom MOSFET switches on with only a diode voltage between its drain and source terminals. The switching loss is negligible due to near zero-voltage switching. The gate losses are estimated as: SCCG GT G BG fVQR RP = The total bottom switch losses are then: BGBCB PPP += Once the power losses for the top and bottom MOSFET are known, thermal and package design at component and system level should be done to verify that the maxi- mum die junction temperature (Tj,max, usually 125°C) is not exceeded under the worst-case condition. The equiva- lent thermal impedance from junction to ambient ( θJA) should satisfy: ,,JM A X A M A X JA LOSS TT Pθ −≤ θJA depends on the die to substrate bonding, packaging material, the thermal contact surface, thermal compound property, the available effective heat sink area, and the air flow condition (natural or forced convection). Actual temperature measurement of the prototype should be carried out to verify the thermal design. PC Board Layout Issues Circuit board layout is very important for the proper op- eration of high frequency switching power converters. A power ground plane is required to reduce ground bounces. The followings are suggested for proper layout. Power Stage 1) Separate the power ground from the signal ground. In SC2542 design, use an isolated local ground plane for the controller and tie it to power grand. 2) Minimize the size of the high pulse current loop. Keep the top MOSFET, the bottom MOSFET and the input ca- pacitors within a small area with short and wide traces. In addition to the aluminum energy storage capacitors, add multi-layer ceramic (MLC) capacitors from the input to the power ground to improve high frequency bypass. 3) Reduce high frequency voltage ringing. Widen and shorten the drain and source traces of the MOSFETs to reduce stray inductances. Add a small RC snubber if nec- essary to reduce the high frequency ringing at the phase node. Sometimes slowing down the gate drive signal also helps in reducing the high frequency ringing at the phase node if the EMI is a concern for the system. 4) Shorten the gate drive trace. Integrity of the gate drive (voltage level, leading and falling edges) is impor- tant for circuit operation and efficiency. Short and wide gate drive traces reduce trace inductances. Bond wire inductance is about 2~3nH. If the length of the PCB trace from the gate driver to the MOSFET gate is 1 inch, the trace inductance will be about 25nH. If the gate drive current is 2A with 10ns rise and falling times, the voltage drops across the bond wire and the PCB trace will be 0.6V and 5V respectively. This may slow down the switch- ing transient of the MOSFET. These inductances may also ring with the gate capacitance. 5) Put the decoupling capacitor for the gate drive power supplies (BST and PVCC) close to the IC and power ground. Control Section 6) The frequency-setting resistor Rosc should be placed close to Pin 23. Trace length from this resistor to the analog ground should be minimized. 7) Place the bias decoupling capacitor right across the VCC and analog ground AGND. Applications Information (Cont.)

21 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT 5VSBY C12 10uF/25V C272.2n/n.p. C28 2.2n/n.p. VIN+ VCC VO2 VIN+ VO1 Si4800 Q4Si4800 Q2Si4800 Si4800 VIN+ FB1 PWGRD FB1 FB2 FB2 L2 4.7uH C20 470uF/4V C19 330uF/6.3V SB C13 10uF/25V VCC C11 10uF/25V C18 330uF/6.3V 4.7uH L1 C3 4.7uF C1 1uF/25V C10 0.1uF/25V C16 1uF/16V C5 12nF C2 1uF/16V C4 12nF C22 1uF/16V C7 1n F C24 1n/n.p. C9 1uF/16V C25 4.7n F R25 330 EN C8 1uF/16V C6 1n F R26

330 C26

4.7n F C14 10uF/25V 5VSBY C17 0.1uF/25V C15 1uF/16V C23 1n/n.p. VIN1 VCC2 EN3 STBY4 FB15 ERROUT16 MINSET17 SS18 ILIM 19 BST110 DRVH111 PHASE112 PHASE2 17 DRVH2 18 BST2 19 ILIM2 20 SS2 21 MINSET2 22 ERROUT2 23 FB2 24 PWRGD 25 ROSC 26 5VSBY 27 AGND 28 DRVL113 PGND14 PVCC 15 DRVL2 16 GND TH-PAD U1 SC2542 C21470uF/4V R8 88.7k R12 0 R10 15K R14 2.2 R17 2.2/n.p. R20 8.25k R16 28k R9 133k R7 41.2kR6 41.2k R22 R13 0 R19 28k R15 2.2 R18 2.2/n.p. R21 4.87k 10K R4 73.2K R11 15K Typical Applications Schematic

22 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Typical Applications Schematic - BOM feRy tQe cnerefeRe ulaV/rebmuNtraPr erutcafunaM 11 1 C5 080,cimareC,R5X,V52,Fu1y nA 26 2 2C,61C,51C,9C,8C,2C5 080,cimareC,R5X,V61,Fu1y nA 31 3 C6 021cimareC,R5X,V61,Fu7.4y nA 42 5 C,4C3 060,cimareC,Fn21y nA 52 7 C,6C3 060cimareC,Fn1y nA 62 7 1C,01C3 060cimareC,Fn1.0y nA 74 4 1C,31C,21C,11C0 121,cimareC,R5X,V52,Fu01M 601E1BY4JCE,cinosanaP 82 9 1C,81Cp aCsoP,mhom81,V3.6,Fu033L IM033EPT6,oynaS 92 1 2C,02Cp aCsoP,mhom51,V4,Fu074L FM074EPT4,oynaS 014 8 2C,72C,42C,32C. P.N 112 6 2C,52C3 060,cimareC,Fn7.4y nA 212 2 L,1Lm hom51,A8.6,Hu7.47 21HRDC,adimuS 314 4 Q,3A,2Q,1Q0 084iSy ahsiV 411 4 R3 060,K2.37y nA 511 5 R3 060,K01y nA 612 7 R,6R3 060,K2.14y nA 711 8 R3 060,K7.88y nA 811 9 R3 060,K331y nA 912 1 1R,01R3 060,K51y nA 023 2 2R,31R,21R0 y nA 122 5 1R,41R3 060,2.2y nA 222 9 1R,61R3 060,K82y nA 322 8 1R,71R. P.N 421 0 2R3 060,K52.8y nA 521 1 2R3 060,K78.4y nA 622 6 2R,52R3 060,033y nA 721 1 U2 452CSh cetmeS

23 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Typical Characteristics Gate waveform (SPWM Mode) CH1: TG1 CH2: BG1 CH2: TG2 CH2: BG2 Gate waveform (SKIP Mode) CH1: TG1 CH2: BG1 CH2: TG2 CH2: BG2 Start up CH1: TG CH2: BG CH3: Vss CH4: Vo CH1: Vi CH2: Vcc CH3: Vss CH4: Vo Shutdown by pulling down SS pin voltage Shutdown by pulling down EN/STBY pin voltage Transient response (3 ~ 8A CH1: TG CH2: BG CH3: Vss CH4: Vo CH1: Vo CH4: Io

24© 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Typical Characteristics (Cont.) 20% 40% 60% 80% 100% 0123456789 1 0 Io(A ) Effic ient V in=8V V in=16V 0 .00% 20 .00% 40 .00% 60 .00% 80 .00% 100 .00% 10 100 1 000 10 000 Io(mA) Efficiency skip mod e Synchroni ze Over current protection (5A/10mV) CH1: TG CH2: BG CH3: IL CH4: Vo Efficiency curve for Vout = 3.3V Efficiency curve for SPWM Mode vs. SKIP Mode 10 0 15 0 20 0 25 0 30 0 35 0 10 0 11 0 12 0 130 140 150 160 17 0 18 0 Ro sc( KOHM) Fsw (KH z RI LI M(KOHM) Io (A Operating frequency vs. Rosc RILIM vs. OCP (Vin = 12V)

25 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Typical Characteristics (Cont.) Frequency vs. Temp. (Rosc = 75kohm, Vin = 16V) 176 178 180 182 184 186 188 190 192 -40 -15 10 35 60 85 110 135 Temp. (Degree C) Fs (kHz) 9.5 9.7 9.9 10.1 10.3 12 14 16 18 20 22 24 26 28 Vi n ( V) Vcc (V) Vcc vs. Vin (Ta = 25 Degree C) 9.8 9.85 9.9 9.95 -40 -20 0 20 40 60 80 100 120 T emp. (T a De gree C ) Vcc (V) 5. 0 5. 5 6. 0 6. 5 7. 0 8 1 01 21 41 61 82 02 22 42 62 8 Vi n( V) Ic c ( mA) 10 40 10 45 10 50 10 55 10 60 - 4 0 - 2 00 2 04 06 08 0 1 0 0 1 2 0 Temp. (Degree C) Min puls e (nS) 100 - 4 0 - 2 00 2 04 06 08 0 1 0 0 1 2 0 Ta (Degree C) Dead time Vcc vs. Temp. (Ta = 25 Degree C) Minimum pulse width vs. Temp (Ta) Dead time vs. Ta (Vin = 16V, DH falling to DL rising) Icc vs. Vin (Ta = 25 Degree C)

26 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Outline Drawing - TSSOP-28-EDP N AA2 A1bxN PLANE bbb C A-B D ccc C DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS3. OR GATE BURRS. DATUMS AND TO BE DETERMINED AT DATUM PLANE CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). -B- NOTES: 2. -A- -H- SIDE VIEW A B C De H e/2 (.039) .008 .004 .024 .018 .003 E INCHES b N bbb aaa ccc E L e D c DIM A MIN MAX MILLIMETERS DIMENSIONS MINMAXNOM NOM BOTTOM VIEW EXPOSED PAD F H .031 .000 8° 0° 0.20 0.10 - 8° 0.45 0.09 0.80 0.00 .030 .008 .047 .041 .006 0.60 (1.0) 0.75 0.20 - 1.20 1.05 0.15 D REFERENCE JEDEC STD MO-153, VARIATION AET.4. L (L1) c GAGE PLANE SEE DETAIL DETAIL A A 0.25 .026 BSC .252 BSC .004 .169 .173 .007 - 0.10

0.65 BSC

6.40 BSC

4.40 .177 4.30 .012 0.19 4.50 0.30 .382 2X N/2 TIPS SEATING aaa C E/2 INDICATOR PIN 1 213

27 2005 Semtech Corp. www.semtech.com SC2542 POWER MANAGEMENT Land Pattern - TSSOP-28-EDP Semtech Corporation Power Management Products Division

200 Flynn Road, Camarillo, CA 93012

Phone: (805)498-2111 FAX (805)498-3804 Contact Information (.222) (5.65) ZG Y P (C) 4.10.161 0.65.026 0.40.016 1.55.061 7.20.283 X THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. NOTES: F H INCHES DIMENSIONS Z P Y X DIM C G MILLIMETERS F 5.70 .224 H 3.20 .126