EV2112DQ-00A 1a, 1mhz synchronous step-down converter evaluation board EV2112DQ-00A rev. 1.0 www.monolithicpower.com 1 3/17/2006 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2006 mps. all rights reserved. the future of analog ic technology description the ev2111/12dq-00a is an evaluation board for the mp2112dq. the mp2112 is a 1mhz constant frequency, current mode, pwm step-down converter. the device integrates a main switch and a synchronous rectifier for high efficiency without an external schottky diode. it is ideal for powering portable equipment that runs from a single cell lithium-ion (li+) battery. the mp2112 can supply 1a of load current from a 2.5v to 6v input voltage. the output voltage can be regulated as low as 0.6v. the mp2112 can also run at 100% duty cycle for low dropout applications. the mp2112 is available in a space-saving 6-pin 3mmx3mm qfn package with an exposed pad. electrical specifications parameter symbol value units input voltage v in 2.5 ? 6 v output voltage v out 1.8 v output current i out 1 a features ? high efficiency: up to 95% ? 1a available load current ? 2.5v to 6v input voltage range applications ? cellular and smart phones ? microprocessors and dsp core supplies ? pdas ? mp3 players ? set-top box ? digital still and video cameras ? portable instruments ?mps? and ?the future of analog ic technology?, are trademarks of monolithic power systems, inc. ev2111/12dq-00a evaluation board (l x w x h) 2.1?x 2.1? x 0.4? (5.3cm x 5.3cm x 1.0cm) board number mps ic number ev2111/12dq-00a mp2112dq 100 90 80 70 60 50 40 30 20 10 0 efficiency (%) 10 100 1000 load current (ma) mp2112-ec01 efficiency vs load current v in = 3.3v v in = 4.2v
EV2112DQ-00A ? 1a, 1mhz synchro nous step-down converter evaluation board EV2112DQ-00A rev. 1.0 www.monolithicpower.com 2 3/17/2006 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2006 mps. all rights reserved. evaluation board schematic mp2112 en sw fb gnd vinb 2 1 3 6 5 4 vina ev2112_s01 en vout 1.8v @ 1a gnd vin gnd c3 1nf u1 EV2112DQ-00A bill of materials qty ref value description package manufacturer manufacturer p/n ceramic cap., 10v, x7r 1206 c1206c106k8rac ceramic cap., 10v, x7r 1210 kemet c1210c106k8rac ceramic cap., 10v, x7r 1210 avx 1210zc106kat2a 1 c1 10f ceramic cap., 10v, x5r 1210 tdk c3225x5r1a106k 1 c2 22f ceramic cap, 6.3v, x5r 1210 tdk c3225x5r0j226m 1 c3 1nf ceramic cap., 50v, x7r 0805 tdk c2012x7r1h102k 4.7h, 2a, d63cb smd toko a916cy-4r7m 4.7h, 1.87a, d53lc smd toko a915ay-4r7m 1 l1 4.7h 4.7h, 1.6a, cdc5d23 smd sumida cdc5d23b-4r7mc 1 r1 499k ? resistor, 1% 0805 panasonic erj-6enf4993v 1 r2 249k ? resistor, 1% 0805 panasonic erj-6enf2493v 1 r3 220k ? resistor, 5% 0805 panasonic erj-6geyj224v 1 u1 mp2112 dc-dc converter qfn6 mps mp2112dq
EV2112DQ-00A ? 1a, 1mhz synchro nous step-down converter evaluation board EV2112DQ-00A rev. 1.0 www.monolithicpower.com 3 3/17/2006 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2006 mps. all rights reserved. printed circuit board layout figure 1?top silk layer figure 2?top layer figure 3?bottom silk layer
EV2112DQ-00A ? 1a, 1mhz synchro nous step-down converter 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. EV2112DQ-00A rev. 1.0 www.monolithicpower.com 4 3/17/2006 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2006 mps. all rights reserved. quick start guide the output voltage of this board is set to 1.8v, and the board accommodates most commonly used inductors and capacitors. 1. attach the positive and negative ends ot the load to the vout and gnd pins, respectively. 2. attach the input voltage (2.5v v in 6v) and input ground to the vin and gnd pins, respectively. the ic should automatically startup. to operate the ic through the enable pin without automatic startup, first remove resistor r3. apply a voltage greater than 1.5v to enable the ic; lower than 0.3v to shut it off. be careful not to exceed 6v on the en pin. 3. the output voltage of this board can be changed by varying the value of resistor r2. calculate the value of r2 using the equation: 1 v v 1 r 2 r fb out ? = where v fb =0.6v and r1=499k ? . for example, if v out =2.5v is desired: k 158 1 v 6 . 0 v 5 . 2 k 499 2 r = ? = therefore, use a 158k ? (1%) resistor for r2.
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