rev. 1.0 october 2007 www.aosmd.com page 1 of 4 AOZ1017-EVA ezbuck 3a simple buck regulator evaluation board note general description the aoz1017 evaluation board is a fully assembled and tested circuit board built with the aoz1017 buck regulator ic. it outputs a preset or adjustable voltage and up to 3a of continuous current. the evaluation board requires an input voltage from 4.5v to 16v. the output voltage is preset and can be adjusted from 0.8v to v in ?.4v the AOZ1017-EVA circuit features include; current limit, short circuit protection, input under voltage lock out, internal soft start and thermal shut down. it operates at a ?ed 500khz switching frequency. the current mode control and integrated internal mosfet minimize component count, board area and total cost. the aoz1017 comes in so-8 packages and is rated over a -40? to +85? ambient temperature range. features 4.5v to 16v operating input voltage range output voltage was preset to 3.3v, adjustable down to 0.8v 3a continuous output current fixed 500khz pwm operation internal soft start cycle-by-cycle current limit short-circuit protection thermal shutdown applications p oint of load dc/dc conversion pcie graphics cards set top boxes d vd drives and hdd lcd panels cable modems t elecom/networking/datacom equipment evaluation board schematic figure 1. lx vin u1 vout vin from pc fb gnd en comp agnd c1 22f c3 22f c2 22f r1 r2 10k? r c c c d1 c6 nc c5 1000pf c4 nu l1 aoz1017
a oz1017-eva rev. 1.0 october 2007 www.aosmd.com page 2 of 4 component list note: 1. v o is preset to 3.3v. output voltage is set by r1; r1 = (12.5 x v o ) ?10k ? . ta b le 1 shows that the value of r1 with typical output v oltages. tab le 1. ref designation v alue description manufacturer pa rt number manufacturer c1 22? ceramic cap, 22?, 25v, 1210, x5r grm32er61e226ke15l murata c2 22? ceramic cap, 22?, 25v, 1210, x5r grm32er61e226ke15l c3 22? ceramic cap, 22?, 25v, 1210, x5r grm32er61e226ke15l c4 nu c5 1000pf ceramic cap, 1000pf, 50v, 0603, x7r grm188r71e102k c6 nu c c 1000pf ceramic cap, 1000pf, 50v, 0603, x7r grm188r71e222k r c 20k ? thick film res, 1%, 20k, 0603 crcw060331k6fktap dale r1 (1) 31.6k ? thick film res, 1%, 31.6k, 0603 crcw060320k0fktap r2 10k ? thick film res, 1%, 10k, 0603 crcw060310k0fktap l1 4.7? inductor, 4.7?, 6.4a mss1278-472mld coilcraft d1 schottky diode i f(av) = 5a, smd pds540-13 diodes u1 aoz1017ai buck regulator ic, 3a, 16v aoz1017ai aos vo (v) r1 (k ? ) 1.2 4.99 1.8 12.7 2.5 21.5 3.3 31.6 5.0 52.3
a oz1017-eva rev. 1.0 october 2007 www.aosmd.com page 3 of 4 pcb layout figure 1. top silk screen figure 2. top layer figure 3. bottom layer
a oz1017-eva rev. 1.0 october 2007 www.aosmd.com page 4 of 4 quick start guide 1. connect the terminals of load to +v out pins and gnd pins. set load current to between 0a and 3a. 2. connect the dc power supply to +v in pin and gnd pins. set dc power supply voltage to between 4.5v and 16v. 3. connect en pin to +v in or any voltage source which is higher than 2v and less than 16v. 4. turn on dc power supply and evaluation circuit will start. 5. measure input voltage at the +v in pin and gnd pins to eliminate the effect of voltage drop on wire between dc power supply and evaluation board. 6. measure output voltage at the +v out pin and gnd pins to eliminate the effect of voltage drop on wire between load and evaluation board. 7. use an oscilloscope to monitor input ripple voltage right across input capacitor c1. 8. use an oscilloscope to monitor output ripple voltage right across output capacitor c2. as used herein: 1. life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body or (b) support or sustain life, and (c) whose f ailure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a signi?ant injury of the user. 2. a critical component in any component of a life support, device, or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. this datasheet contains preliminary data; supplementary data may be published at a later date. alpha & omega semiconductor reserves the right to make changes at any time without notice. life support policy alpha & omega semiconductor products are not authorized for use as critical components in life support devices or systems.
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