general description the max1572 evaluation kit (ev kit) is a fully assembled and tested circuit board that evaluates the max1572 pwm step-down dc-dc converter. the circuit operates from 2.6v to 5.5v and has a fixed 1.5v output capable of delivering 800ma. it also provides a reset output. the ev kit can be used to evaluate other output voltage versions of the max1572 by replacing the ic. features 2mhz pwm switching 800ma guaranteed output current power-saving modes: pulse group/ pulse skip/forced pwm voltage-positioning load transients 5mv p-p output ripple tiny 2.2h inductor 10f ceramic output capacitor low 0.1a shutdown current soft-start with zero inrush current 170ms (min) reset output thin qfn ic package: 4mm ? 4mm ? 0.8mm fully assembled and tested recommended equipment power supply capable of supplying 500ma from 2.6v to 5.5v voltmeter quick start follow the steps below to verify operation of the max1572 ev kit. do not turn on the power supply until all connections are completed: 1) select the desired operating mode with ju1 and ju2 (see table 1). 2) connect the positive terminal of the voltmeter to the pad labeled out. connect the ground terminal of the voltmeter to the pad labeled gnd nearest the out pad. connect a load from out to the gnd pad closest to out. 3) preset the power supply to between 2.6v and 5.5v, and turn the power supply off. 4) connect the positive power-supply terminal to the pad labeled in. connect the power-supply ground to the pad labeled gnd nearest the in pad. 5) turn on the power supply and verify the output volt- age is 1.5v. evaluates: max1572 max1572 evaluation kit ________________________________________________________________ maxim integrated products 1 19-2901; rev 0; 7/03 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. part temp range ic package MAX1572EVKIT 0 c to +70 c 12 thin qfn-ep* ordering information * ep = exposed paddle. note: when contacting these component suppliers, please specify you are using the max1572 . designation qty description c1, c2 2 10f 20%, 6.3v x5r ceramic capacitors (0805) panasonic ecj2fb0j106m or tdk c2012x5r0j106m or taiyo yuden jmk212bj106mg c3 1 1000pf 10%, 50v x7r ceramic capacitor (0603) murata grm188r71h102k or equivalent c4 1 0.1f 10%, 16v x7r ceramic capacitor (0603) taiyo yuden emk107bj104ka or equivalent r1 1 10 ? 5% resistor (0603) ju1, ju2 2 3-pin headers l1 1 2.2h inductor, 0.17 ? , 1.2a 3.6mm ? 3.6mm ? 1.2mm toko 976as-2r2m (d312f family) u1 1 max1572etc150 (12-pin thin qfn 4mm ? 4mm) none 2 shunts, position 2 none 1 max1572 ev kit pc board component list supplier phone website kamaya 260-489-1533 www.kamaya.com murata 770-436-1300 www.murata.com panasonic 714-373-7939 www.panasonic.com taiyo-yuden 408-573-4150 www.t-yuden.com tdk 847-803-6100 www.component.tdk.com toko 847-297-0070 www.toko.com component suppliers
evaluates: max1572 detailed description operating modes the operating mode is selected with ju1 and ju2, as shown in table 1. for details on each operating mode, refer to the max1572 data sheet. reset output a connection is provided on the max1572 ev kit for evaluating the reset output of the max1572. reset is an open-drain output with an internal 14k ? pullup resis- tor to out. refer to the max1572 data sheet for details on the operation of reset . abatt filter an rc filter is included on the ev kit to reduce the power-supply noise entering the ic through abatt. to evaluate the circuit without the filter, short r1 on the pc board and remove c4. evaluating other output voltages the max1572 ev kit comes with the 1.5v output version of the max1572 installed. to evaluate other voltage ver- sions, replace the ic with the voltage version part to evaluate. max1572 output voltages range from 0.75v to 2.5v. samples of the standard versions are available from maxim. refer to the max1572 data sheet for order- ing information. when evaluating output voltages less than 1.5v, replace c2 with a 22f ceramic capacitor. max1572 evaluation kit 2 _______________________________________________________________________________________ ju1 ju2 en1 pin en2 pin mode 1-2 1-2 gnd gnd shutdown 1-2 2-3 gnd in pulse group 2-3 1-2 in gnd pulse skip 2-3 2-3 in in forced pwm table 1. ju1 and ju2 functions max1572 3 2 1 ju1 3 2 1 ju2 in c1 10 f c4 0.1 f r1 10 ? reset l1 2.2 h out gnd c2 10 f c3 1000pf exposed paddle connected to gnd u1 9 12 10 6 1 11 batt abatt en1 en2 gnd reset 8 7 4 2 3 5 gnd gnd ss out pgnd lx figure 1. max1572 ev kit schematic
evaluates: max1572 max1572 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 _____________________ 3 ? 2003 maxim integrated products printed usa is a registered trademark of maxim integrated products. figure 2. max1572 ev kit component placement guide?op silkscreen figure 3. max1572 ev kit pc board layout?omponent side figure 4. max1572 ev kit pc board layout?older side
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