1 f requency reference input, sma differential output, sma 3.3 v d
supply , banana jacks 5 v d
supply , banana jacks r ibbon cable connection to d
590 loop filter component s mute jumper description ltc 6948 ultralow noise and spurious fractional-n synthesizer with integrated vco demonstration circuit 1959a features the LTC6948, an ultralow noise and spurious fractional-n synthesizer with integrated vco. there are four options of the dc1959a, one for each ver - sion of the LTC6948. table 1 summarizes the available dc1959a options. the dc1959a provides 50 sma connectors for the ref - erence frequency input f ref (ref+in) and the differential rf output (rf+ and rfC). l , lt, ltc, ltm, linear technology and the linear logo are registered trademarks and fracnwizard is a trademark of linear technology corporation. all other trademarks are the property of their respective owners. a dc590 usb serial controller board is used for spi com - munication with the LTC6948, controlled by the supplied fracnwizard? software. design files for this circuit board are available at http://www .linear.com/demo/dc1959a figure 1. dc1959a connections dc1959af demo manual dc1959a
2 quick start procedure the dc1959a is easy to set up to evaluate the performance of the LTC6948. follow the procedure below. the dc590 and fracnwizard application are required to control the dc1959a through a personal computer (pc). dc590 configuration place the dc590 jumpers in the following positions (refer to figure 2): jp4: ee C must be in the en position. jp5: iso C on must be selected. jp5: sw C on must be selected. jp6: vccio C 3.3v must be selected. this sets the spi port to 3.3v operation. connect the dc590 to one of your computers usb ports with the included usb cable. fracnwizard installation the fracnwizard software is used to communicate with the LTC6948 synthesizer. it uses the dc590 to translate between usb and spi- compatible serial communica - tions formats. it also includes advanced pll design and simulation capabilities. the following are the fracnwizard system requirements: n windows operating system: windows xp, windows 2003 server, windows vista, windows 7 n microsoft .net 3.5 sp1 or later n windows installer 3.1 or later n linear technologys dc590 hardware figure 2. dc590 jumper and connector locations ? ? jp6 ? jumpers ? j4, ? ribbon ? cable ? connection ? to ? the ? dc1959 ? jp5 ? jumpers ? jp4 ? jumper ? j3, ? usb ? connection ? to ? pc ? dc1959af demo manual dc1959a
3 download the fracnwizard setup file at www.linear.com/ fracnwizard. run the fracnwizard setup file and follow the instructions given on the screen. the setup file will verify and/or install microsoft .net and install the fracnwizard. refer to the help menu for software operation. dc1959a configuration 1. connect a 100mhz reference frequency source to ref+ in (at j1) and signal analyzers to rf+ and/or rfC (at j5 and/or j4) using the sma connectors (see figure 1 and the typical dc1959a requirements and characteristics table). be sure to terminate any unused rf output with 50, or poor spurious performance may result. 2. choose the mute jumper setting: jp1: gnd/3.3v C mute position. select gnd to mute the rf output, 3.3v to un-mute. 3. connect the gnd, 3.3v, and 5v banana jacks to a power supply and apply power (see figure 1 and the typical dc1959a requirements and characteristics table). 4. connect the dc590 to the dc1959a with the provided ribbon cable. 5. run the fracnwizard application. 6. in fracnwizard, click file -> load settings and point to the LTC6948-1_100mhz. fracnset file in case of evaluat - ing the LTC6948-1, for instance, or load the appropriate file depending on which option of the LTC6948 you are evaluating. the red led on the dc1959a should turn on indicating that the loop is locked and the output is at 907mhz. quick start procedure figure 3. fracnwizard screenshot dc1959af demo manual dc1959a
4 assembly options typical dc1959a requirements and characteristics troubleshooting if the red led does not illuminate, follow the instructions below: 1. verify that you are able to communicate with the dc 1959 a . the bottom status line in fracnwizard should read LTC6948 and comm enabled as shown in figure 3. refer to fracnwizards troubleshoot and help if not. 2. verify that the 3.3v and 5v have the correct voltages on them and that the reference frequency is applied to the ref+in sma input. if the red led is on but you cannot detect an rf output, make sure jumper jp1 is at the 3.3v position. run help -> troubleshoot in fracnwizard if the problem is not resolved. dc1959a reconfiguration you can redesign the frequency plan of the dc1959a using fracnwizard. you can change the loop filter as found us - ing fracnwizard by reinstalling the loop filter components shown in figure 1. quick start procedure table 1. dc1959a options and frequency ranges assembly version part number vco frequency range (ghz) output divider settings dc1959a-a LTC6948iufd-1 2.240 to 3.740 integers 1 through 6 dc1959a-b LTC6948iufd-2 3.080 to 4.910 integers 1 through 6 dc1959a-c LTC6948iufd-3 3.840 to 5.790 integers 1 through 6 dc1959a-d LTC6948iufd-4 4.200 to 6.390 integers 1 through 6 parameter input or output physical location details 3.3v power supply input j6 and j7 banana jacks low-noise and spur-free 3.3v, 130ma 5v power supply input j8 and j9 banana jacks low-noise and spur-free 5v, 33ma ref+ in, reference frequency input j1 sma connector low-noise 100mhz*, 6dbm to 10dbm into 50, see note below rf+ and rfC tw o outputs j4 and j5 sma connectors** frequency: 907mhz*, power: 0dbm, frequency range: depends on the version of the LTC6948 device C refer to table 1 loop bandwidth C set by loop filter component values approximately 160khz* depending on the dc1959a version *these frequencies are for the dc1959a fracnset files included with fracnwizard. **any unused rf output must be terminated with 50, or poor spurious performance may result. note: a low noise 100mhz reference frequency, such as the wenzel 501-04516d ocxo, is recommended. if using a different frequency, make sure to update the fref and r_div boxes under the system tab in fracnwizard so that fpfd is still 50mhz. for example, if a 250mhz clock is used, fref should be changed to 250mhz and r_div to 5. ref bst and filt under the system tab in fracnwizard might need to be changed if the reference frequency and/or power is different than what is recommended in the table above. more information can be found in the LTC6948 data sheet. dc1959af demo manual dc1959a
5 pcb layout the top metal layer of the dc1959a is shown here as an example of good pcb layout for the LTC6948. dc1959af demo manual dc1959a
6 parts list item qty reference part description manufacturer / part number required circuit components 1 0 ci2 cap., 0805 opt 2 5 c1, c8, c9, c15, c18 cap., x7r, 1.0f, 16v, 10%, 0603 tdk, c1608x7r1c105k 3 2 c2, c10 cap., tant., 330f, 10v, 10%, 7343 avx , tpme337k010r0035 4 9 c3, c7, c17, c22-c27 cap., x7r, 0.1f, 10v, 10%, 0402 tdk, c1005x7r1a104k 5 2 c6, c11 cap., x5r, 1.0f, 16v, 10%, 0402 tdk, c1005x5r1c105k 6 3 c12, c13, c19 cap., x7r, 0.01f, 16v, 10%, 0402 avx , 0402yc103 kat 2a 7 1 c16 cap., x5r, 2.2f, 16v, 10%, 0603 tdk, c1608x5r1c225k 8 0 c2_f2, c28 cap., 0603 opt 9 2 c20, c21 cap., x7r, 100pf, 50v, 10%, 0402 avx , 04025c101 kat 2a 10 1 d1 led, red panasonic , ln1251c-tr 11 1 e3 turret, testpoint, 2501 mill-max, 2501-2-00-80-00-00-07-0 12 1 jp1 headers, 3 pins 2mm ctrs. samtec, tmm-103-02-l-s 13 3 j1, j4, j5 con., sma 50 edge-launch e.f. johnson, 142-0701-851 14 1 j2 con., header, 14 pin, 2mm molex, 87831-1420 15 4 j6, j7, j8, j9 jack, banana keystone, 575-4 16 2 l1, l2 ind., 68nh 5%, 0402 coilcraft , 0402hph-68 nxjlw 17 1 l1_f1 ind., 10h, 0805 tdk, mlf2012e100k 18 0 l1_f2 ind., 0805 opt 19 1 r1 res., chip, 51.1, 1/16w, 1%, 0402 nic, nrc04f51r1trf 20 0 r1_f2 res., 0603 opt 21 4 r2, r18, r19, r20 res., chip, 0, 0402 nic , nrc04z0trf 22 1 r3 res., chip, 330, 1/16w, 1%, 0402 nic, nrc04f3300trf 23 1 r4 res., chip, 15, 1/16w, 1%, 0402 nic, nrc04f15r0trf 24 4 r5, r6, r7, r13 res., chip, 200k, 1/16w, 1%, 0402 nic, nrc04f2003trf 25 3 r8, r9, r14 res., chip, 4.99k, 1/16w, 1%, 0402 nic, nrc04f4991trf 26 3 r10, r11, r12 res., chip, 100 1/16w, 5%, 0402 nic, nrc04j101trf 27 1 r15 res., chip, 0, 0603 nic, nrc06z0trf 28 2 u2, u3 i.c., dual buffer, sc70-6 fairchild semi., nc7wz17p6x 29 1 u4 i.c., dual transceiver, sot363 nxp, 74 lv c 1t45gw+125 30 1 u5 i.c., serial eeprom, tssop8 microchip, 24lc025-i /st 31 1 shunt on jp1 shunt, 2mm ctrs. samtec 2sn-bk-g dc1959af demo manual dc1959a
7 item qty reference part description manufacturer / part number dc1959a-a required circuit components 1 1 dc1959a general bom 2 1 c2_f1 cap., c0g, 2.4nf, 50v, 5%, 0603 murata , grm1885c1h242ja01d 3 1 ci1 cap., x7r, 82nf, 50v, 10%, 0603 murata , grm188r71h823ka93d 4 1 cp cap., c0g, 3.6nf, 50v, 5%, 0603 murata , grm1885c1h362ja01d 5 2 r1_f1, rz res., chip, 57.6, 1/16w, 1%, 0603 nic, nrc06f57r6trf 6 1 u1 i.c. synthesizer, qfn28ufd-4x5 linear tech., LTC6948iufd-1 dc1959a-b required circuit components 1 1 dc1959a general bom 2 1 c2_f1 cap., c0g, 2nf, 50v, 5%, 0603 murata , grm1885c1h202ja01d 3 1 ci1 cap., x7r, 68nf, 50v, 10%, 0603 murata , grm188r71h683ka93d 4 1 cp cap., c0g, 3nf, 50v, 5%, 0603 murata , grm1885c1h302ja01d 5 2 r1_f1, rz res., chip, 63.4, 1/16w, 1%, 0603 nic, nrc06f63r4trf 6 1 u1 i.c. synthesizer, qfn28ufd-4x5 linear tech., LTC6948iufd-2 dc1959a-c required circuit components 1 1 dc1959a general bom 2 1 c2_f1 cap., x7r, 1.8nf, 50v, 10%, 0603 murata , grm188r71h182ka01d 3 1 ci1 cap., x7r, 56nf, 50v, 10%, 0603 murata , grm188r71h563ka93d 4 1 cp cap., c0g, 2.4nf, 50v, 5%, 0603 murata , grm1885c1h242ja01d 5 2 r1_f1, rz res., chip, 75, 1/16w, 5%, 0603 vishay , crcw060375r0jnea 6 1 u1 i.c. synthesizer, qfn28ufd-4x5 linear tech., LTC6948iufd-3 dc1959a-d required circuit components 1 1 dc1959a general bom 2 1 c2_f1 cap., c0g, 1.6nf, 50v, 5%, 0603 murata , grm1885c1h162ja01d 3 1 ci1 cap., x7r, 56nf, 50v, 10%, 0603 murata , grm188r71h563ka93d 4 1 cp cap., c0g, 2.4nf, 50v, 5%, 0603 murata , grm1885c1h242ja01d 5 2 r1_f1, rz res., chip, 76.8, 1/16w, 1%, 0603 nic, nrc06f76r8trf 6 1 u1 i.c. synthesizer, qfn28ufd-4x5 linear tech., LTC6948iufd-4 parts list dc1959af demo manual dc1959a
8 schematic diagram 5 5 4 4 3 3 2 2 1 1 d d c c b b a a vco 2.24 to 3.74 ghz 3.08 to 4.91 ghz 3.84 to 5.79 ghz assy u1 * a LTC6948iufd-1 LTC6948iufd-2 LTC6948iufd-3 note: unless otherwise specified 1. all resistors are in ohms, 0402 2. all capacitors are in microfarads, 0402 LTC6948iufd-4 4.20 to 6.39 ghz b c d ci1 r1_f1, rz c2_f1 cp 3.6nf 82nf 57.6 2.4nf 3nf 68nf 63.4 2nf 2.4nf 56nf 75 1.8nf 56nf 76.8 1.6nf 2.4nf 3.3v 5v 3.3v 3.3v 3.3v 3.3v 3.3v 3.3v 5v cs sclk sdo sdi size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 2 demo circuit 1959a 01/27/2014, 12:05 pm 12 ultralow noise & spurious fractional-n n/a LTC6948iufd-1/-2/-3/-4 kim t. michel a. synthesizer with integrated vco size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 2 demo circuit 1959a 01/27/2014, 12:05 pm 12 ultralow noise & spurious fractional-n n/a LTC6948iufd-1/-2/-3/-4 kim t. michel a. synthesizer with integrated vco size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 2 demo circuit 1959a 01/27/2014, 12:05 pm 12 ultralow noise & spurious fractional-n n/a LTC6948iufd-1/-2/-3/-4 kim t. michel a. synthesizer with integrated vco revision history description date approved eco rev michel a. production 2 01-27-14 __ revision history description date approved eco rev michel a. production 2 01-27-14 __ revision history description date approved eco rev michel a. production 2 01-27-14 __ r2 0 r2 0 r19 0 r19 0 c6 1uf c6 1uf l2 68nh 0402hph-68nxjl l2 68nh 0402hph-68nxjl c12 0.01uf c12 0.01uf c8 1uf 0603 c8 1uf 0603 r18 0 r18 0 jp1 gnd 3.3v mute jp1 gnd 3.3v mute 1 3 2 c2_f1 * 0603 c2_f1 * 0603 c20 100pf c20 100pf j1 sma-r ref+ in j1 sma-r ref+ in c27 0.1uf c27 0.1uf + c2 330uf 10v 7343 + c2 330uf 10v 7343 c9 1uf 0603 c9 1uf 0603 r1_f1 * 0603 r1_f1 * 0603 c16 2.2uf 0603 c16 2.2uf 0603 l1 68nh 0402hph-68nxjl l1 68nh 0402hph-68nxjl j5 sma-r rf+ j5 sma-r rf+ j7 gnd j7 gnd c21 100pf c21 100pf r3 330 r3 330 j9 gnd j9 gnd j8 5v j8 5v c22 0.1uf c22 0.1uf tune tune j6 3.3v j6 3.3v r20 0 r20 0 e3 status e3 status r4 15 r4 15 c19 0.01uf c19 0.01uf c28 opt 0603 c28 opt 0603 l1_f2 opt 0805 l1_f2 opt 0805 r1_f2 opt 0603 r1_f2 opt 0603 c7 0.1uf c7 0.1uf ci2 opt 0805 ci2 opt 0805 c2_f2 opt 0603 c2_f2 opt 0603 cp * 0603 cp * 0603 c15 1uf 0603 c15 1uf 0603 j4 sma-r rf- j4 sma-r rf- ci1 * 0603 ci1 * 0603 r1 51.1 r1 51.1 c17 0.1uf c17 0.1uf c13 0.01uf c13 0.01uf + c10 330uf 10v 7343 + c10 330uf 10v 7343 d1 ln1251c d1 ln1251c 2 1 c11 1uf c11 1uf u1 * qfn28ufd-4x5 u1 * qfn28ufd-4x5 stat 2 tune 15 cs 3 mute 9 sdi 5 v+d 8 ldo 7 rf+ 12 rf- 11 gnda 10 sclk 4 tb 16 gndb 17 v+rf 13 ref+ 1 bb 14 sdo 6 cmc 18 cmb 19 cma 20 gndc 21 bvco 22 v+vco 23 gndd 24 v+cp 25 cp 26 v+ref 27 ref- 28 gnd 29 c18 1uf 0603 c18 1uf 0603 l1_f1 10uh 0805 l1_f1 10uh 0805 rz * 0603 rz * 0603 c1 1uf 0603 c1 1uf 0603 dc1959af demo manual dc1959a
9 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. schematic diagram 5 5 4 4 3 3 2 2 1 1 d d c c b b a a note: eeprom for board identification dc590 spi interface 3.3v 3.3v 3.3v 3.3v cs sclk sdi sdo size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 2 demo circuit 1959a 01/27/2014, 11:57 am 22 ultralow noise & spurious fractional-n n/a LTC6948iufd-1/-2/-3/-4 kim t. michel a. synthesizer with integrated vco size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 2 demo circuit 1959a 01/27/2014, 11:57 am 22 ultralow noise & spurious fractional-n n/a LTC6948iufd-1/-2/-3/-4 kim t. michel a. synthesizer with integrated vco size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: (408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 2 demo circuit 1959a 01/27/2014, 11:57 am 22 ultralow noise & spurious fractional-n n/a LTC6948iufd-1/-2/-3/-4 kim t. michel a. synthesizer with integrated vco r11 100 r11 100 c23 0.1uf c23 0.1uf r12 100 r12 100 c3 0.1uf c3 0.1uf cs cs sdo sdo r7 200k r7 200k v+dig v+dig r10 100 r10 100 r15 0 0603 r15 0 0603 r6 200k r6 200k j2 hd2x7-079-molex j2 hd2x7-079-molex mosi/sda 7 eesda 9 v+ 1 5v 2 cs 6 sck/scl 4 eevcc 10 miso 5 eescl 11 eegnd 12 aux 14 gnd 3 gnd 13 gnd 8 r5 200k r5 200k eeprom array u5 24lc025-i /st eeprom array u5 24lc025-i /st sda 5 vcc 8 a0 1 a1 2 a2 3 gnd 4 wp 7 scl 6 wp wp c24 0.1uf c24 0.1uf r13 200k r13 200k gnd dir vcc(a) vcc(b) u4 74lvc1t45gw gnd dir vcc(a) vcc(b) u4 74lvc1t45gw 1 6 4 3 5 2 eegnd eegnd r8 4.99k r8 4.99k c25 0.1uf c25 0.1uf sdi sdi r9 4.99k r9 4.99k gnd vcc u3 nc7wz17p6x gnd vcc u3 nc7wz17p6x 1 6 4 3 5 2 r14 4.99k r14 4.99k c26 0.1uf c26 0.1uf gnd vcc u2 nc7wz17p6x gnd vcc u2 nc7wz17p6x 1 6 4 3 5 2 sclk sclk note: the buffers shown on sheet 2 of 2 of the schematic are used to protect the LTC6948 when connected to the dc590 before the LTC6948 is powered up. there is no need for such circuitry if the spi bus is not active before powering up the LTC6948. the eeprom is for identification and is not needed to program the LTC6948. dc1959af demo manual dc1959a
10 linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax : (408) 434-0507 www.linear.com ? linear technology corporation 2014 lt 0414 ? 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 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 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 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 technology corporation dc1959af demo manual dc1959a
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