ev 24893d j - 00a step - down white led driver evaluation board ev 24 893 d j - 00a rev.1. 1 www.monolithicpower.com 1 5/1/2018 mps proprietary information. patent protected . unauthorized photocopy and duplication prohibited. ? 2018 mps . all rights reserved. description the ev24893dj - 00a is an evaluation board for the mp24893dj , a step - down converter designed in continuous current mode for driving the high brightness leds from wide input voltage of 6v to 30v. the mp24893 employs hysteretic control architecture to regulate a highly accurate led current, which is measured through an external high - side current - sense resistor. moreover, this control scheme provides optimal circuit stabilization and a very quick response time without loop compensation. its low 200mv average feedback voltage reduces power loss and improves the converter efficiency. the mp24893 implements pwm and analog dimming together through the dim pin. the mp24893 includes under - voltage lockout, thermal overload protection to prevent damage in the event of an output overload. electrical specifica tion s parameter symbol value units input voltage v in 6 C 3 0 v output voltage vout ev 24 89 3 d j - 00a step - down white led driver evaluation board ev 24 893 d j - 00a rev.1. 1 www.monolithicpower.com 2 5/1/2018 mps proprietary information. patent protected . unauthorized photocopy and duplication prohibited. ? 2018 mps . all rights reserved. evaluation board sch ematic ev 24 893 dj - 00a bill of materials qty ref value description package manufacturer part number 1 c1 2.2f ceramic capacitor, 50v, x7r 1206 mu rata grm31cr71h225ka88l 1 c2 220f electrolytic capacitor, 35v dip sanyo 220f/35v 1 c3 1nf ceramic capacitor, 25v, cog 0603 murata grm1885c1e102ja01d 2 c4, c5 nc 5 d1 - d5 b260a schottky diode sma diodes inc. b260a 1 l1 100h inductor 1.3a smd coop er sd8350 - 101 - r 1 r1 0.4 ? resistor, 1% 0805 royalohm 0805f400lt5e 3 r2, r3, r4 nc 1 r5 0 ? resistor, 5% 0603 yageo rc0603jr - 070rl 1 r6 nc 1 q1 nc 1 u1 mp24893dj mps wled driver tsot23 - 5 mps mp24893dj - r2
ev 24 89 3 d j - 00a step - down white led driver evaluation board ev 24 893 d j - 00a rev.1. 1 www.monolithicpower.com 3 5/1/2018 mps proprietary information. patent protected . unauthorized photocopy and duplication prohibited. ? 2018 mps . all rights reserved. printed circuit boar d layout figure 1 top layer figure 2 bottom layer
ev 24 89 3 d j - 00a step - down white led driver evaluation board notice: the information in this document is subject to change without notice. users should warrant and guarantee that third party intellectual property rights are not infringed upon when integrating mps products into any application. mps will not assume any legal responsibility for any said applications. ev 24 893 d j - 00a rev.1. 1 www.monolithicpower.com 4 5/1/2018 mps proprietary information. patent protected . unauthorized photocopy and duplication prohibited. ? 2018 mps. all rights reserved. quick start guide 1. connect the positive and negative terminals of the load to the led+ and led - pins on the ev board, respectively. 2. connect the positive and negative terminals of the 24v ac power supply to t he ac1 and ac2. if apply a dc power supply, please connect + and C to ac1 and ac2. turn the power supply on. 3. if pwm dimming is required, provide a 200hz to 2khz pwm signal to en /dim pin. remove r5 and put a 1 k? resistor on r4. if analog dimming is required, please open r4 and short r5 , then provide a 0.3v - to - 2.5v dc voltage to the en/dim pin . 4. t he led current is adjustable by set current sense resistor r1 / /r2 as below formula, r1//r2= 20 2 mv /i led
|
