EV1542DK-SEPIC-00A 700khz/1.3mhz boost converter with a 2a switch evaluation board EV1542DK-SEPIC-00A rev. 1.0 www.monolithicpower.com 1 6/15/2005 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2005 mps. all rights reserved. the future of analog ic technology tm tm general description the EV1542DK-SEPIC-00A is the demo board for sepic applications using the mp1542, a current mode step up converter with a 2a, 0.18 ? internal switch to provide a highly efficient regulator with fast response. the EV1542DK-SEPIC-00A can be operated at 700khz or 1.3mhz allowing for easy filtering and low noise. an external compensation pin gives the user flexibility in setting loop dynamics, which allows the use of small, low esr ceramic output capacitors. the soft-start results in small inrush current and can be programmed with an external capacitor. the EV1542DK-SEPIC-00A can operate from a single li-ion battery to generate 3.3v at up to 500ma. other features include under voltage lockout, current limiting and thermal overload protection, all available in a low profile 8-pin msop package. electrical specifications parameter symbol value units input voltage v in 3 ? 4.2 v output voltage v out 3.3 v output current i out 500 ma features ? automatic up-down conversion ? operates from a single li-ion battery to generate 3.3v at up to 500ma ? uses tiny capacitors and inductors ? pin selectable 700khz or 1.3mhz fixed switching frequency ? programmable soft-start ? uvlo, 2a switch, thermal shutdown ? internal current limit applications ? lcd displays ? portable applications ? handheld computers and pdas ? digital still and video cameras ?mps? and ?monolithic power system s?, are trademarks of monolithic power systems, inc. EV1542DK-SEPIC-00A evaluation board dimensions (2.0?x x 2.0?y x 0.0?z) board number mps ic number EV1542DK-SEPIC-00A mp1542dk 90 80 70 60 50 40 30 20 10 0 efficiency (%) 1 10 100 1000 load current (ma) ev1542_ec02 efficiency vs load current v in =4.2v v in =3.6v v in =3v
EV1542DK-SEPIC-00A ? 700khz/1.3mhz sepic converter with a 2a switch evaluation board EV1542DK-SEPIC-00A rev. 1.0 www.monolithicpower.com 2 6/15/2005 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2005 mps. all rights reserved. tm evaluation board schematic mp1542 in fb sw comp 7 3 8 gnd en fsel ss 5 6 4 2 1 vout 3.3v 0.5a gnd c3 1nf c6 ns d1 1n5819hw-7 d2 1n4148 t1 cooper drq73-3r3 ev1542-sepic_s01 c4 22nf c2b ns vin 3v - 4.2v gnd en u1 jp1 frequency selection EV1542DK-SEPIC-00A bill of materials qty ref value description package manufacturer manufacturer p/n 2 c1a, c1b 10f ceramic cap, 6.3v, x5r 1210 tdk c3225x5r1a106k 1 c2a 22f ceramic cap, 6.3v, x5r 1210 tdk c3225x5r0j226m 1 c3 1nf ceramic cap, 50v, x7r 0805 tdk c2012x7r1h102k 1 c4 22nf ceramic cap, 100v, x7r 0805 tdk c2012x7r2a223m 1 c5 4.7f ceramic cap, 10v, y5v 0805 tdk c2012y5v1a475z 2 c6, c2b ns not stuffed 1 c7 1f ceramic cap, 10v, x5r 0805 tdk c2012x5r1a105k 1 d1 schottky diode, 40v, 1a sod-123 diodes inc 1n5819hw-7 1 d2 rectifier diode, 75v, 200mw sod-323 diodes inc 1n4148ws-7 1 jp1 3-pin connector header, 0.100 sullins ptc03saan 1 l1 3.3h transformer, 1.66a cooper drq73-3r3 1 r1 16.4k ? metal film resistor, 1% 0805 panasonic erj-6enf1642v 1 r2 10k ? metal film resistor, 1% 0805 panasonic erj-6enf1002v 1 r3 20k ? metal film resistor, 5% 0805 panasonic erj-6geyj203v 2 r4, r5 100k ? metal film resistor, 5% 0805 panasonic erj-6geyj104v 1 u1 dc-dc converte r msop8 mps mp1542dk
EV1542DK-SEPIC-00A ? 700khz/1.3mhz sepic converter with a 2a switch evaluation board EV1542DK-SEPIC-00A rev. 1.0 www.monolithicpower.com 3 6/15/2005 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2005 mps. all rights reserved. tm printed circuit board layout figure 1?top silk layer figure 2?top layer figure 3?bottom layer
EV1542DK-SEPIC-00A ? 700khz/1.3mhz sepic converter with a 2a switch evaluation board notice: the information in this document is subject to change wi thout notice. please contact mps for current specifications. users should warrant and guarantee that third party intellectual property rights ar e not infringed upon when integrating mps products into any application. mps will not assume any legal responsibility for any said applications. EV1542DK-SEPIC-00A rev. 1.0 www.monolithicpower.com 4 6/15/2005 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2005 mps. all rights reserved. tm quick start guide the output voltage of this board is set to 3.3v. the board layout accommodates most commonly used inductors and output capacitors. 1. preset the power supply to 3v v in 6v. 2. turn the power supply off. 3. connect the power supply terminals to: a. positive (+): vin, en b. negative (?): gnd 4. connect the load to: a. positive (+): vout b. negative (?): gnd 5. turn on the power supply after making connections. 6. the mp1542 is enabled on the evaluation board once v in is applied. to disable the mp1542, disconnect en from in. 7. the output voltage v out can be changed by varying r1. calculate the new value using the formula: 2 r 1 v v 1 r fb out ? ? ? ? ? ? ? ? ? = where v fb = 1.25v and r2 = 10k ? for example, for v out = 5v ? = ? ? ? ? ? ? ? ? = k 30 k 10 1 v 25 . 1 v 5 1 r therefore use a 30.1k ? standard 1% value. 8. the switching frequency is set to 1.3mhz if jumper jp1 is shunted at the h position. to get 700khz operation, shunt jp1 at the l position.
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