ev0020 (MP1591DN) 2a, 32v, 330khz step-down converter evaluation board ev0020 (MP1591DN) rev. 1.5 www.monolithicpower.com 1 12/21/2005 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2005 mps. all rights reserved. the future of analog ic technology description the ev0020 is the evaluation board for the mp1591; a high voltage step-down converter ideal for automotive power adapter battery chargers. its wide 6.5v to 32v input voltage range covers the automotive battery?s requirements. it achieves 2a continuous output for quick charge capability. current mode operation provides fast transient response and eases loop stabilization. fault protection includes cycle-by-cycle current limiting and thermal shutdown. in shutdown mode, the converter draws only 20a of supply current. the mp1591 requires a minimum number of readily available external components to complete a 2a step-down dc to dc converter solution. electrical specifications parameter symbol value units input voltage v in 6.5 to 32 v output voltage v out 5 v output current i out 2 a features ? wide 6.5v to 32v input operating range ? 34v absolute maximum input ? 2a output current ? ceramic input and output capacitors ? up to 95% efficiency ? 20a shutdown mode ? fixed 330khz frequency ? thermal shutdown ? cycle-by-cycle over current protection ? output adjustable from 1.23v to 21v ? under voltage lockout applications ? automotive power adapters ? pda and cellular phone battery chargers ? distributed power systems ? automotive aftermarket electronics ?mps? and ?the future of analog ic technology? are registered trademarks of monolithic power systems, inc. ev0020 evaluation board (l x w x h) 2.1? x 1.4? x 0.5? (5.3cm x 3.5cm x 1.1cm) board number mps ic number ev0020 MP1591DN
ev0020 (MP1591DN) ? 2a, 32v, 330khz step-down converter evaluation board ev0020 (MP1591DN) rev. 1.5 www.monolithicpower.com 2 12/21/2005 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2005 mps. all rights reserved. evaluation board schematic c1 10nf c3 1.8nf jp1 off d1 b340a-13 u1 mp1591 vin bs sw fb gnd ref comp en c6 ns vin gnd ref en vout gnd c4 ns ev0020_s01 ev0020 bill of materials qty ref value description package manufacturer manufacturer p/n 1 c1 10nf ceramic capacitor, 50v, x7r 0805 avx 08055c103kat2a 1 c2 10 f ceramic capacitor, 35v 1210 taiyo yuden gmk325f106mh 1 c3 1.8nf ceramic capacitor, 50v, x7r 0805 avx 08055c182kat2a 2 c4, c6 ns not stuffed 1 c5 22 f ceramic capacitor, 10v, 1210 1210 taiyo yuden lmk325bj226mm 1 d1 schottky diode, 40v, 3a, sma diodes inc b340a-13 1 r1 47k ? film resistor, 1% 0805 yageo 9c08052a4702fkhft 1 r2 8.2k ? film resistor, 5% 0805 panasonic erj-6geyj822v 1 r3 15k ? film resistor, 1% 0805 yageo 9c08052a1502fkhft 1 l1 22 h inductor, 2.6a sumida cdrh8d43-220 l1 alternate 22 h inductor, 2.5a, type d104c toko 919as-220m 1 u1 step-down converter so8 mps MP1591DN
ev0020 (MP1591DN) ? 2a, 32v, 330khz step-down converter evaluation board ev0020 (MP1591DN) rev. 1.5 www.monolithicpower.com 3 12/21/2005 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2005 mps. all rights reserved. printed circuit board layout figure 1?top silk layer figure 2?top layer figure 3?bottom layer
ev0020 (MP1591DN) ? 2a, 32v, 330khz 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. ev0020 (MP1591DN) rev. 1.5 www.monolithicpower.com 4 12/21/2005 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2005 mps. all rights reserved. quick start guide the output voltage of this board is set to 5v. the board layout accommodates most commonly used inductors and output capacitors. 1. attach the positive and negative ends of the load to vout and gnd, respectively. 2. attach the input voltage (6.5v v in 32v) and input ground to vin and gnd, respectively. 3. to enable to the mp1591, apply a voltage (v en 2v) to the en pin. to disable it, connect the en pin to ground. 4. the ref pin outputs a 5v reference voltage. if used, a 0.01 f capacitor should be connected from this pin to gnd to reduce switching ripple. leave unconnected if not used. 5. the output voltage v out can be changed by varying r1. calculate r1 using the formula: ? ? ? ? ? ? ? ? ? = 1 v v 3 r 1 r fb out where v fb = 1.23v and r3 is set at 15k ? . for example, for v out = 5.0v: ? ? = ? ? ? ? ? ? ? ? = ? ? ? ? ? ? ? ? ? = k 47 k 98 . 45 1 v 23 . 1 v 0 . 5 k 15 1 v v 3 r 1 r fb out standard 1% value. see maximum duty cycle limits to determine allowable output voltage range.
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