general description the max 8632 evaluation kit (ev kit) is designed to evalu- ate the max 8632 ddr power-supply solution for note- books, desktops, and graphics cards. the ev kit board produces vddq at the output of the synchronous pwm buck, vtt at the output of the sourcing/sinking ldo linear regulator, and vttr at the output of the reference buffer. the vddq output is preset to 1.8v and sources up to 10a. the vtt output is always vddq/2 and can source/sink up to 3a of peak current and 1.5a of continu- ous current. the vttr output is also always vddq /2 and can source/sink up to 10ma. the max8632 ev kit was conveniently designed with jumpers to select the ovp/uvp, ton, skip , stby , and shdn modes. the board? default settings enable ovp (overvoltage protection), 300khz switching frequency, low-noise pwm mode, vddq, vtt, and vttr. the vin input accepts voltages from 7v to 20.5v and vdd requires a 5v bias supply. features ? vddq preset to 1.8v/10a ? vtt 0.9v source/sink 1.5a continuous/3a peak ? vttr 0.9v source/sink 10ma ? v in range: 7v to 20.5v ? optimized switching frequency: 300khz ? overvoltage/undervoltage protection ? independent shutdown and standby controls ? power ok evaluates: max8632 max8632 evaluation kit ________________________________________________________________ maxim integrated products 1 19-3840; rev 0; 10/05 component list for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. ordering information part temp range ic package MAX8632EVKIT 0? to +70? 28 thin qfn 5mm x 5mm designation qty description c1 1 0.1? ?0%, 16v x7r (0603) ceramic capacitor taiyo yuden emk107bj104ma c2, c4a, c4b 3 10? ?0%, 6.3v x5r (0805) ceramic capacitors kemet c0805c106k9pac taiyo yuden jmk212bj106mg c3, c6 2 1? ?0%, 10v x5r (0603) ceramic capacitors tdk c1608x5r1a105k c5 1 4.7? ?0%, 6.3v (0805) x5r ceramic capacitor tdk c2012x5r0j475m c7, c10 2 0.22? ?0%, 16v x7r (0603) ceramic capacitors tdk c1608x7r1c224m c8a, c8b, c8c 3 10? ?0%, 25v x5r (1210) ceramic capacitors taiyo yuden tmk325bj106mm tdk c3225x5r1e106m designation qty description c9 1 4700pf ?0%, 50v x7r (0603) ceramic capacitor kemet c0603c472k5rac or equivalent c11, c12 2 150?, 4v, 18m ? pos capacitors sanyo 4tpe150mi d1 1 s chottky d i od e, 30v , 100m a ( s od - 3 23) central cmdsh-3 ju1?u4, ju6 5 3-pin headers, 0.1in center 36-pin header, 0.1in center sullins ptc36saan or equivalent digi-key s1012-36-nd l1 1 1.4?, 15.5a, 2.8m ? power inductor sumida cep125-1r4mc-u q1 1 30v, 12m ? (so-8) n-channel mosfet international rectifier irf7821 q2 1 30v, 4m ? (so-8) n-channel mosfet international rectifier irf7832
evaluates: max8632 max8632 evaluation kit 2 _______________________________________________________________________________________ max8632 evaluation kit recommended equipment 5vdc power supply (500ma rated) 7vdc to 20.5vdc power supply (5a rated) two digital voltmeters (dvm) quick start the max8632 ev kit is fully assembled and tested. follow these steps to verify board operation. do not turn on the power supplies until all connections are completed. 1) ensure a shunt is placed across pins 1-4 of jumper ju2 to enable ovp and uvp. 2) ensure jumper ju1 is open to set the switching fre- quency to approximately 300khz. 3) ensure a shunt is placed across pins 1-2 of jumper ju3 to enable low-noise pwm mode. 4) ensure a shunt is placed across pins 2-3 of jumper ju4 to disable the vddq buck output. 5) ensure a shunt is placed across pins 2-3 of jumper ju6 to set the board in normal operation mode. 6) connect the 5vdc power supply across the vdd pad and the gnd pad nearest vin. 7) connect the 12vdc power supply across the vin pad and the corresponding gnd pad. 8) turn on both of the power supplies. 9) set ju4 (1-2). this turns vddq on. 10)using one of the dvms, verify that the vddq voltage between the vddq and pgnd pads is 1.8v (?%). 11) using the other dvm, verify that the vtt voltage between the vtt and pgnd pads is 0.9v (?%). detailed description jumper selection setting the buck regulator output voltage (vddq) the output voltage of the buck regulator is preset to 1.8v on the max8632 ev kit for ddr memory applica- tions. to pin-strap the output voltage to 2.5v, follow the steps below: 1) remove r18. 2) solder the 0 ? resistor from step 1 in the r9 location. refer to the max8632 data sheet to change the external components for optimum performance. component list (continued) designation qty description r1 1 10 ? ?% (0603) resistor r2, r3, r4 3 100k ? ?% (0603) resistors r5 1 36.5k ? ?% (0603) resistor r13 1 20 ? ?% (0603) resistor r18 1 0 ? ?% (0603) resistor u1 1 integrated ddr power supply (28-pin, 5mm x 5mm, thin qfn) max8632eti+ 5 shunts sullins stc02syan digi-key s9000-nd or equivalent jumper shunt position description ju2 1-2 disable ovp and uvp. ju2 1-3 enable uvp. disable ovp. ju2 1-4* enable ovp and uvp. ju2 open enable ovp. disable uvp. * default position. note: refer to the max8632 data sheet for additional informa- tion on ovp/uvp. table 1. overvoltage/undervoltage control input (ovp/uvp) component suppliers supplier phone website central semiconductor 631-435-1110 www.centralsemi.com international rectifier 310-322-3331 www.irf.com kemet 864-963-6300 www.kemet.com sanyo usa 619-661-6835 www.sanyo.com sumida 847-545-6700 www.sumida.com taiyo yuden 800-348-2496 www.t-yuden.com tdk 847-803-6100 www.component.tdk.com note: indicate that you are using the max8632 when contact- ing these component suppliers.
evaluates: max8632 max8632 evaluation kit _______________________________________________________________________________________ 3 jumper shunt position description ju1 1-2 600khz switching frequency ju1 1-3 450khz switching frequency ju1 1-4 200khz switching frequency ju1 open* 300khz switching frequency * default position. note: refer to the max8632 data sheet for additional informa- tion on ton. table 2. on-time selection input (ton) jumper shunt position description ju3 1-2* low-noise pwm mode. ju3 2-3 pulse-skipping mode. * default position. note: refer to the max8632 data sheet for additional informa- tion on skip . table 3. pulse-skipping control input ( skip ) jumper shunt position description ju4 1-2 the vddq buck output is enabled. ju4 2-3* the vddq buck output is shut down. * default position. note: refer to the max8632 data sheet for additional informa- tion on shdn . table 4. shutdown control input ( shdn ) jumper shunt position description ju6 2-3 the vtt output is shut down. ju6 1-2* normal operation. * default position. note: refer to the max8632 data sheet for additional informa- tion on stby . table 5. standby control input ( stby )
evaluates: max8632 max8632 evaluation kit 4 _______________________________________________________________________________________ c4a 10 f j1 j13 4 3 1 2 ju1 j3 j15 r18 0 ? r17 short r9 open r8 open ref vdd c10 0.22 f c9 4700pf c14 open r4 100k ? r2 100k ? r3 100k ? r7 open r10 short r11 short r19 open r14 short r6 open r12 open c2 10 f r16 open c16 open c15 open c1 0.1 f ju3 1 2 3 r13 20 ? vdd d1 cmdsh-3 q1 irf7821 q2 irf7832 c7 0.22 f c5 4.7 f c13 open c11 150 f 4v c8a?8c 3 x 10 f 25v l1 1.4 h j9 j8 vin 7v to 20.5v pgnd vdd 4.5v to 5.5v j7 j5 vdd ju6 1 2 3 3 2 1 ju4 vdd shdn stby max8632 u1 vtti vtt 0.9v at 3a vttr 0.9v at 10ma vddq 1.8v at 10a pgnd jp1 j11 j12 j10 vtts vtt pgnd2 vttr ovp/uvp ton pok1 pok2 pok1 pok2 ss ref ilim tpo tab 4 8 28 29 3 5 6 j2 gnd gnd gnd 1 10 24 11 12 9 13 vtti 14 refin 25 skip v in av dd v dd bst dh dl lx pgnd1 shdn stby fb out 7 15 16 27 23 20 18 19 21 22 26 17 vdd ref 4 3 1 2 ju2 2 vdd ref vdd vdd vdd vdd r1 10 ? c6 1 f j14 r5 36.5k ? c3 1 f c4b 10 f c12 150 f 4v figure 1. max8632 ev kit schematic
evaluates: max8632 max8632 evaluation kit _______________________________________________________________________________________ 5 max8632 evaluation kit figure 2. max8632 ev kit component placement guide?omponent side
evaluates: max8632 max8632 evaluation kit 6 _______________________________________________________________________________________ figure 3. max8632 ev kit pc board layout?omponent side
evaluates: max8632 max8632 evaluation kit _______________________________________________________________________________________ 7 figure 4. max8632 ev kit pc board layout?nner layer 2
evaluates: max8632 max8632 evaluation kit 8 _______________________________________________________________________________________ figure 5. max8632 ev kit pc board layout?nner layer 3
evaluates: max8632 max8632 evaluation kit maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 _____________________ 9 2005 maxim integrated products printed usa is a registered trademark of maxim integrated products, inc. max8632 evaluation kit figure 6. max8632 ev kit pc board layout?older side
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