1 description ada 4899 -1 rail-to-rail sar adc driver amplifier demonstration circuit 2622 a features the ada 4899-1 amplifier . the dc 2622 a includes two of these amplifiers and is designed to drive the inputs of the dc 2290 demo board . the dc 2290 features the ltc ? 2387 18- bit , 15 msps high speed sar adc . the linearity and low noise of the ada 4899-1 make it an ideal candidate to drive the ltc 2387 at frequencies above 1 mhz . see table 1. the dc 2622 a is configured to accept a single - ended in - put s ignal a nd provide unity gain . the board can provide voltage gain if several component values are changed. for l , lt, ltc, ltm, linear technology and the linear logo are registered trademarks of analog devices, inc. all other trademarks are the property of their respective owners. example , a voltage gain of two will result if the following changes are made : ch ange r23 to 309 ins tall 309 at r 27 ins tall 100 pf at c 28 ch ange r 18 to 287 design files for this circuit board are available at http : // www . li near . com / demo / dc 2622 a figure 1. dc2622a connection diagram from signal source from dc common mode reference to dc2290 ?5v +10v dc2622 f01 table 1. dc2290 (ltc2387 family) driver boards input frequency driver board amplifier up to 8khz dc2402 lt6237 up to 1mhz dc2403 lt6200 >1mhz lowest noise dc2622 lowest distortion dc2623 ada 4899-1 ltc6404-1 + ad8002 dc2622af demo manual dc2622a
2 quick s tart p roce d ure connect the dc2622a to a dc2290a using the two output sma connectors j1, j3. connect the +10 v and C5 v dc supplies to the turrets on the dc2622a. apply a 2.048v har d ware s etup signal connections j2 in. this is the signal input. j3 Cout. this is the negative signal output. j1 +out. this is the positive signal output. dc voltage, preferably from e7 of the dc2290a, to 2.048v in turret of the dc2622a. dc2622af demo manual dc2622a
3 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 c h ematic diagram c23 10f c10 0.1f c21 10f c11 68pf c8 0.1f ?2.5v +7.5v r23 0 r10 24.9 c13 0.1f r8 10 r14 24.9 r25 49.9 r18 590 r6 0 r9 49.9 l1 820nh l2 270nh c26 10f c18 0.1f c24 10f c17 68pf c16 0.1f ?2.5v +7.5v r15 24.9 r19 590 r23 0 r21 49.9 l5 820nh l6 270nh j1 +out dc2622af demo manual dc2622a u3 ADA4899-1 in u2 lt1763 c13 0.01f gnd in shdn adj out u1 lt1964-sd c3 1f ?2.5v c1 22f c4 10f r2 1.05k gnd c5 1f c2 22f c6 10f r1 1k adj r4 5.11k +7.5v r3 1k 2.048v c28 dni c27 10f c9 100pf j2 in u4 ADA4899-1 j3 ?out c14 100pf r11 100 ?5vin r12 300 r13 300 c12 68pf r27 dni l3 82nh r7 562 r5 49.9 c7 100pf r20 100 r16 300 +10vin c15 68pf r17 300 l4 82nh r22 562 r24 49.9 c19 100pf out gnd byp shdn
4 lt 0317 ? printed in usa ? linear technology corporation 2017 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 lt c 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 lt c from all claims arising from the handling or use of the goods. due to the open construction of the product, it is the users 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 whatsoever. lt c assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. lt c 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 lt c applica- tion engineer. mailing address: linear technology 1630 mccarthy blvd. milpitas, ca 95035 copyright ? 2004, linear t echnology corporation dc2622af demo manual dc2622a
|
