1 description lt 8714 synchronous four-quadrant converter demonstration circuit 2240a is a synchronous four- quadrant converter featuring the lt ? 8714 switching controller . the LT8714 can regulate to positive , negative , or zero volts when configured as a four-quadrant topol - ogy . the dc2240 a r egulates from a 10v to 14v input source to an adjustable output voltage from positive 5v to negative 5v with a 5a maximum current rating , and operates at 200khz switching frequency . the LT8714 incorporates a power good feature to let the user know if the output voltage is within its target regulation voltage . the LT8714 has an output voltage control ( ctrl ) pin which sets the output voltage . the dc2240 a has a l , lt, ltc, ltm, linear technology and the linear logo are registered trademarks of linear technology corporation. all other trademarks are the property of their respective owners. p erformance s ummary jumper to select the ctrl pin voltage source from either externally ( ext ) or internally ( int ). if selected internally , the output voltage can be set to + 5v or C 5v . if selected externally , the output voltage can vary between positive 5v and negative 5v , following a 0. 1v C 1v ctrl signal with high bandwidth . the LT8714 data sheet gives a complete description of the part, operation and application information. the data sheet must be read in conjunction with this quick start guide for demo circuit 2240a. design files for this circuit board are available at http://www . linear.com/8714 specifications are at t a = 25c figure 1. dc2240a connection diagram parameter conditions min typ max units input voltage 10 12 14 v positive output voltage (max) v in = 10v C 14v 4.85 5 5.15 v negative output voltage (max) v in = 10v C 14v C4.85 C5 C5.15 v maximum output current 5 a positive output voltage ripple v in = 10v C 14v, v out = 5v, i out = 5a (20mhz bw) 25 mv p-p negative output voltage ripple v in = 10v C 14v, v out = C5v, i out = C5a (20mhz bw) 25 mv p-p typical switching frequency 200 khz efficiency v in = 12v, v out = 5v, i out = 5a 89 % v in = 12v, v out = C5v, i out = C5a 80 % dc2240af demo manual dc2240a
2 quick s tart p roce d ure demonstration circuit 2240a is easy to set up to evalu - ate the performance of the LT8714. refer to figure 1 for proper measurement equipment setup and follow the procedure below : 1. with the power off, connect the input power supply to the board through v in and pgnd terminals . connect the load to the terminals v out and pgnd on the board. make sure that the input power supply has sufficient current rating at minimum input voltage for the required output load. 2. turn on the power at the input. note: make sure that the input voltage does not exceed 14v . 3. check for the proper output voltages. the output should be regulated at +5.0v (3%). if there is no output , temporarily disconnect the load to make sure that the load is not set too high. 4. once the proper output voltage is established, adjust the input voltage and load current within the operating range and observe the output voltage regulation , ripple voltage, efficiency and other parameters. note: when measuring the input or output voltage ripples, care must be taken to avoid a long ground lead on the oscilloscope probe . measure the input or output voltage ripple by touching the probe tip directly across the v in and pgnd , or v out and pgnd terminals . see figure 2 for proper scope probe technique. figure?1. proper measurement equipment setup dc2240a f01 + ? + ? + ? power supply v in + ? + ? v out i in i out dc2240af demo manual dc2240a
3 quick s tart p roce d ure figure?2. proper scope probe placement for measuring input or output ripple figure?3. typical efficiency curve figure?4. output voltage varies between C5v and +5v, following an externally controlled 0.1v to 1v, 1khz sinusoidal voltage source output current (a) 0.5 efficiency (%) 100 55 95 85 75 65 90 80 70 60 50 2.5 4.5 1.5 3.5 dc2240a f03 5.0 2.0 4.0 1.0 3.0 v in = 10v, v o = +5v v in = 12v, v o = +5v v in = 14v, v o = +5v v in = 10v, v o = ?5v v in = 12v, v o = ?5v v in = 14v, v o = ?5v 500s/div v ctrl 0.5v/div v out 5v/div dc2240a f04 input or output capacitor dc2240af demo manual dc2240a
4 p arts list item qty reference part description manufacturer/part number required circuit components 1 4 cin1, cin2, cin3, cin4 cap., x5r, 22f, 25v, 10%, 1210 murata, grm32er61e226ke15l 2 6 c1, c2, c3, c4, c20, c21 cap., x5r, 22f, 25v, 10%, 1210 murata, grm32er61e226ke15l 3 2 co1, co2 cap., x5r, 100f, 10v, 20%, 1210 murata, grm32er61a107me20k 4 3 c7, c8, c9 cap., x7r, 2.2f, 25v, 10%, 0805 murata, grm21br71e225ka73l 5 1 c10 cap., x7r, 0.68f, 25v, 10%, 0603 tdk, c1608x7r1e684k080ab 6 1 c11 cap., x7r, 0.068f, 25v, 10%, 0603 murata, grm188r71e683ka01d 7 1 c12 cap., x7r, 0.01f, 25v, 10%, 0603 murata, grm188r71e103ka01d 8 1 c13 cap., x7r, 100pf, 25v, 10%, 0603 avx, 06033c101kat2a 9 1 c15 cap., x7r, 0.1f, 16v, 10%, 0603 murata, grm188r71c104ka01d 10 1 l1 inductor, 15h coilcraft, xal1510-153 11 1 l2 inductor, 15h coilcraft, xal1010-153 12 1 mn1 n-ch fet, pg-tdson-8 infineon, bsc034n06ns 13 1 mp1 p-ch fet, dpak fairchild, fdd4141 14 1 r1 res., sense, 7 m, 1%, rl3720w susumu, rl3720wt-r007-f 15 1 r2 res., sense, 2 m, 1%, rl3720w susumu, rl3720wt-r002-f 16 6 r3, r4, r5, r6, r9, r10 res., 0, 0.1w, 1%, 0603 vishay, crcw06030000z0ea 17 1 r7 res., 10k, 1/10w, 1%, 0603 vishay, crcw060310k0fkea 18 1 r8 res., 57.6k, 1/10w, 1%, 0603 vishay, crcw060357k6fkea 19 1 r16 res., 6.98k, 1/10w, 1%, 0603 vishay, crcw06036k98fkea 20 1 r19 res., 18.7k, 1/10w, 1%, 0603 vishay, crcw060318k7fkea 21 3 r12, r15, r18 res., 100k, 1/10w, 1%, 0603 vishay, crcw0603100kfkea 22 1 r13 res., 73.2k, 1/10w, 1%, 0603 vishay, crcw060373k2fkea 23 1 r14 res., 100, 1/10w, 1%, 0603 vishay, crcw0603100rfkea 24 1 r17 res., 178k, 1/10w, 1%, 0603 vishay, crcw0603178kfkea 25 1 r19 res., 18.7k, 1/10w, 1%, 0603 vishay, crcw060318k7fkea 26 1 r20 res., 1, 1/4w, 1%, 1206 vishay, crcw12061r00fkea 27 1 r22 res., 1.78k, 1/10w, 1%, 0603 vishay, crcw06031k78fkea 28 1 u1 i.c., voltage regulator, 20tssop linear technology, LT8714efe#pbf 29 1 fab, printed circuit board demo circuit 2240a additional demo board circuit components 1 0 co3, co4 ( opt ) cap., option, 1210 2 0 c5, c6, c16, c17 (opt) cap., option, 0603 3 0 c18 (opt) cap., option, 0805 4 0 vr1 (opt) trimmer, opt 5 0 r21 (opt) res., opt, 0603 6 0 mn2 (opt) n-ch fet, option, dpak 7 0 mp2 ( opt ) p-ch fet, option, pg-tdson-8 hardware: for demo board only 1 13 e1-e13 testpoint, turret, .094" pbf mill-max, 2501-2-00-80-00-00-07-0 2 1 jp1 header 3 pin 0 .079 single row wur th elektronik, 620 003 111 21 3 1 jp2 header 3 pin 0.079 double row wurth elektronik, 620 006 211 21 4 2 xjp1, xjp2 shunt, 0.079" center wurth elektronik, 608 002 134 21 5 4 mh1-mh4 stand-off, nylon 0.50" keystone, 8833 (snap on) dc2240af demo manual dc2240a
5 information furnished by linear technology corporation is believed to be accurate and reliable . however, no responsibility is assumed for its use. linear technology corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights . s chematic diagram e e d d c c b b a a d d c c b b a a 1. all resistors and capacitors 0603. note: unless otherwise specified. en ng en intvcc sync imon isn isp tg vin pg tg isp isn sync imon vout intvcc ng pg vin c12 10nf c2 22uf 1210 25v r18 100k r3 0 c3 c11 68nf r19 18.7k 0603 e10 sync e5 vout 5v / 5a co1 100f 10v 1210 cin3 22f 25v 1210 e13 vctrl 0.1v - 1v c20 c18 opt 0805 co4 opt mp2 opt pg-tdson-8 4 5 1 2 3 c6 opt c15 100nf r21 opt 0603 c17 opt r20 1 1206 r4 0 c8 2.2f 0805 r13 73.2k 1% c21 c7 2.2f 0805 r22 1.78k 0603 l1 xal1510-153 15uh e4 r6 0 co3 opt jp1 int ext 1 3 2 c16 opt e2 vin 10v - 14v cin1 22f 25v 1210 c10 680nf mp1 fdd4141 r15 100k 0603 r14 100 r1 0.002 1% rl3720w r10 0 e9 en r16 6.98k cin2 22f 25v 1210 e6 e12 agnd jp2 +5v -5v opt 1 2 3 5 6 4 c13 100pf r2 0.007 rl3720w c1 22uf 1210 25v e3 pgnd e8 u1 LT8714efe isn 6 isp 7 tg 10 bg 11 csp 15 csn 14 vin 13 en 16 ctrl 17 sync 19 bias 8 intvee 9 pg 4 fb 1 vc 2 imon 5 gnd 21 gnd 20 rt 18 ss 3 intvcc 12 c5 opt r7 10k c9 2.2f 0805 mn1 bsc034n06ns 4 1 5 2 3 r8 57.6k l2 xal1010-153 15uh r9 0 opt vr1 1 3 2 e7 pgnd cin4 22f 25v 1210 co2 100f 10v 1210 c4 22uf 25v 1210 mn2 opt dpak r17 178k 1% r12 100k r5 0 e11 imon e1 dc2240af demo manual dc2240a
6 linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax : (408) 434-0507 www.linear.com ? linear technology corporation 2015 lt 1015 ? printed in usa demonstration board important notice linear technology corporation ( lt c ) provides the enclosed product(s) under the following as is conditions: this demonstration board (demo board) kit being sold or provided by linear technology is intended for use for engineering development or evaluation purposes only and is not provided by ltc for commercial use . as such, the demo board herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods . as a prototype, this product does not fall within the scope of the european union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. if this evaluation kit does not meet the specifications recited in the demo board manual the kit may be returned within 30 days from the date of delivery for a full refund . the foregoing warranty is the exclusive warranty made by the seller to buyer and is in lieu of all other warranties , expressed, implied, or statutory , including any warranty of merchantability or fitness for any particular purpose . except to the extent of this indemnity , neither party shall be liable to the other for any indirect, special, incidental, or consequential damages. the user assumes all responsibility and liability for proper and safe handling of the goods. further , the user releases ltc from all claims arising from the handling or use of the goods. due to the open construction of the product, it is the user s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. also be aware that the products herein may not be regulatory compliant or agency certified (fcc, ul, ce, etc.). no license is granted under any patent right or other intellectual property whatsoeve r. ltc assumes no liability for applications assistance , customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. ltc currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. please read the demo board manual prior to handling the product. persons handling this product must have electronics training and observe good laboratory practice standards. common sense is encouraged. this notice contains important safety information about temperatures and voltages. for further safety concerns, please contact a ltc applica- tion engineer. mailing address: linear technology 1630 mccarthy blvd. milpitas, ca 95035 copyright ? 2004, linear technology corporation dc2240af demo manual dc2240a
|
