1 ? isl85001eval1z: 1a regulator standard buck pwm description the isl85001eval1z rev a kit is intended for use by individuals with requirements for point-of-load applications sourcing from 4.5v to 25v. the isl85001eval1z evaluation board is used to demonstrate the performance of the isl85001 standard buck regulator. the isl85001 is offered in a 4mmx3mm 12 ld dfn package with 1mm maximum height. the complete converter occupies less than 0.425in 2 area. features ? standard buck controller with integrated switching power mosfet ? integrated boot diode ? input voltage range - fixed 5v 10% - variable 5.5v to 25v ? pwm output voltage adjustable from 0.6v to 19v with continuous output current up to 1a ? voltage mode control with voltage feed-forward ? fixed 500khz switching frequency ? externally adjustable soft-start time ? output undervoltage protection ? enable inputs ? pgood output ? overcurrent protection ? thermal overload protection ? internal 5v ldo regulator applications ? general purpose ? wlan cards-pcmcia, cardbus32, minipci cards-compact flash cards ? hand-held instruments ? lcd panel ? set-top box what?s inside the evaluation board kit contains the following materials: ? the isl85001 eval rev a board ? the isl85001 datasheet ? this eval kit document recommended equipment the following materials are recommended to perform te s t i n g : ? 0v to 25v power supply with at least 5a source current capability, battery, notebook ac adapter ? one electronic load capable of sinking current up to 5a ? digital multimeters (dmms) ? 100mhz quad-trace oscilloscope ? signal generator quick setup guide 1. ensure that the circuit is co rrectly connected to the supply and loads prior to applying any power. 2. connect the bias supply to vin, the plus terminal to tp1 (vin) and the negative return to tp2 (gnd). 3. verify that sw1 is on enable. 4. turn on the power supply. 5. verify the pg is on and th e output voltage is 2.5v for vout(tp3). evaluating the other output voltage the isl85001eval kit outputs are preset to 2.5v; however, it can be programmed using resistor dividers using equation 1: the output voltage programming resistor r 2 will depend on on the feedback resistor r 1 , as referred to in figure 1. the value of r 1 is typically between 1k and 10k . if the output voltage desired is 0.6v, then r 2 is left opened. table 1. switch 1 settings sw1 enable operating mode 1 sw1 enable or disabl e the buck controller r 2 r 1 0.6v ? v out 0.6v ? ---------------------------------- = (eq. 1) r1 r2 0.6v ea reference + - v out figure 1. external resistor divider december 1, 2008 an1443.0 application note caution: these devices are sensitive to electrosta tic discharge; follow proper ic handling procedures. 1-888-intersil or 1-888-468-3774 | intersil (and design) is a registered trademark of intersil americas inc. copyright intersil americas inc. 2008. all rights reserved all other trademarks mentioned are the property of their respective owners.
2 an1443.0 december 1, 2008 isl85001eval1z schematic populate r30 if vin <6v only off 1 c8 1 tp4 2 47uf 470pf 10k r2 220uf 1uf 0.1uf fb comp isl8500irz vin gnd 10uf 47pf open 10k pg 2.43k vout en 2n7002 on en 100k vin pg vdd vdd phase open open 3.16k 0.1uf 301 2200pf boot 30k 1 c10 1 2 l1 tp3 c9 tp1 1 tp2 1 d3 2 1 d1 2 1 c11 sw1 2 3 1 q4 3 1 2 r4 c2 c20 1 2 r30 r12 tp16 1 tp13 1 c21 1 c13 1 2 c12 1 2 r20 r21 c3 1 2 c1 2 r3 r1 c4 1 2 sp1 2 3 4 1 sp2 2 3 4 1 u1 1 10 11 12 2 3 4 5 67 8 9 13 1 2 fb comp ss pg en gnd vin vin phase phase boot vdd ep application note 1443
3 an1443.0 december 1, 2008 isl85001eval1z bill of materials part number qty units reference designator description mfr manufacturer part isl85001eval1zrevapcb 1 ea see label-rename board pwb-pcb, isl85001eval1z, reva, rohs titan isl85001eval1zrevapcb c1608x7r1h104k-t 1 ea c9 capacitor, smd, 0603, 0.10f, 50v, 10%, x7r tdk c1608x7r1h104k h1044-00104-16v10-t 1 ea c4 cap, smd, 0402, 0.1f, 16v, 10%, x7r, rohs murata grm36x7r104k016ad h1044-00222-50v10-t 1 ea c1 cap, smd, 0402, 2200pf, 50v, 10%, x7r, rohs panasonic ecj-0eb1h222k h1044-00470-50v5-t 1 ea c2 cap, smd, 0402, 47pf, 50v, 5%, npo, rohs murata grm36cog470j050aq H1044-00471-50V10-T 1 ea c3 cap, smd, 0402, 470pf, 50v, 10%, x7r, rohs panasonic ecj-0eb1h471k h1045-00105-6r3v10-t 1 ea c8 cap, smd, 0603, 1f, 6.3v, 10%, x5r, rohs panasonic ecj1vb0j105k h1065-00106-25v10-t 1 ea c10 cap, smd,1206,10f, 25v, 10%, x5r, rohs venkel c1206x5r250-106kne h1082-00476-16v20-t 1 ea c12 cap, smd, 1210, 47f, 16v, 20%, x5r, rohs tdk c3225x5r1c476m ihlp2525czer220m11 1 ea l1 coil-pwr inductor, smd, 6.9x6.5, 22h, 20%, 7a, rohs vishay ihlp2525czer220m11 131-4353-00 2 ea sp1, sp2 conn-scope probe test pt, compact, pcb mnt, rohs tektronix 131-4353-00 1514-2 4 ea tp1 to tp4 conn-turret, terminal post, th, rohs keystone 1514-2 5002 2 ea tp13, tp16 conn-mini test point, vertical, white, rohs keystone 5002 b340lb-13-f-t 1 ea d1 diode-schottky, smd, smb, 2p, 40v, 3a low vf, rohs diodes inc. b340lb-13-f ltst-c170ckt 1 ea d3 led-gaas red, smd, 2x1.25mm,100mw, 40ma, 10mcd, rohs liteon/visha y ltst-c170ckt isl85001irz 1 ea u1 ic-2a buck regulator, 12p, dfn, 4x3, rohs intersil isl85001irz 2n7002-7-f-t 1 ea q4 transistor, n-channel, 3ld, sot-23, 60v, 115ma, rohs diodes,inc. 2n7002-7-f h2510-01002-1/16w1-t 1 ea r2 res, smd, 0402, 10k, 1/16w, 1%, tf, rohs panasonic erj-2rkf1002 h2510-01003-1/16w1-t 1 ea r12 res, smd, 0402, 100k, 1/16w, 1%, tf, rohs panasonic erj2rkf1003 h2510-03002-1/16w1-t 1 ea r1 res, smd, 0402, 30k, 1/16w, 1%, tf, rohs yageo rc0402fr-0730kl h2510-03010-1/16w1-t 1 ea r3 res, smd, 0402, 301 , 1/16w, 1%, tf, rohs panasonic erj-2rkf3010x application note 1443
4 an1443.0 december 1, 2008 h2510-03161-1/16w1-t 1 ea r4 res, smd, 0402, 3.16k, 1/16w, 1%, tf, rohs venkel cr0402-16w-3161ft h2511-01002-1/10w1-t 1 ea r21 res, smd, 0603, 10k, 1/10w, 1%, tf, rohs koa rk73h1jt1002f h2511-02431-1/10w1-t 1 ea r20 res, smd, 0603, 2.43k, 1/10w, 1%, tf, rohs venkel cr0603-10w-2431ft h2511-dnp 0 ea r30 res, smd, 0603, dnp- place holder, rohs gt11mscbe-t 1 ea sw1 switch-toggle, smd, ultramini, 1p, spst mini c&k components gt11mscke 4-40x1/2-screw 4 ea four corners screw, 4-40x1/2in, pan, nylon, phillips, rohs 4-40x3/4-standoff 4 ea four corners standoff, 4-40x3/4in, f/f, hex, nylon keystone 1902d 5x8-static-bag 1 ea place assy in bag. bag, static, 5x8, zip loc intersil 212403-013 dnp 0 ea c11, c13, c20, c21 do not populate or purchase label-rename board 1 ea rename pcb to: isl85001eval1z label, to rename brd label-serial number 1 ea label, for serial number and bom rev # isl85001eval1z bill of materials (continued) part number qty units reference designator description mfr manufacturer part application note 1443
5 an1443.0 december 1, 2008 isl85001eval1z board layout figure 2. top components figure 3. top layer etch isl85001eval1z application note 1443
6 intersil corporation reserves the right to make changes in circuit design, software and/or specifications at any time without n otice. accordingly, the reader is cautioned to verify that the application note or technical brief is current before proceeding. for information regarding intersil corporation and its products, see www.intersil.com an1443.0 december 1, 2008 figure 4. bottom layer components (mirrored) figure 5. bottom layer etch (mirrored) isl85001eval1z board layout (continued) application note 1443
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