1 description lt c7106eddb a 7- bit current dac with digital pmbus interface demonstration circuit 2620a -a uses the LTC7106EDDB, a precision, bidirectional, 7-bit current dac with pmbus interface and can be used to adjust the output voltage of any conventional v fb referenced regulator. the ltc7106 can work with the vast majority of power management controllers, regulators or modules to enable digital control of the output voltage. the dc2620a-a requires input voltage range from 2.5v to 5.5v, which can be powered either by external supply or directly from the dc1613a dongle. the ltc7106 pro - vides three ranges of idac output current : nominal range ( C 64a to 63a), range high (C 256a to 252a ) and range low (C16a to 15.75a). only the nominal range is optimized with the highest accuracy. it is recommended that users design the resistor divider using the nominal range of the idac setting. all registered trademarks and trademarks are the property of their respective owners. performance summary to explore the power system management features of the parts, download the gui software ltpowerplay ? onto your pc and use adi s i 2 c/smbus/pmbus dongle dc1613a to connect to the board. ltpowerplay allows the user to reconfigure the part on-the-fly, view idac current value and fault status. gui download the software can be downloaded from: http://www.linear.com/ltpowerplay for more details and instructions of ltpowerplay, please refer to ltpowerplay for ltc7106 quick start guide. design files for this circuit board are available at http://www.linear.com/demo/dc2620a-a specifications are at t a = 25c symbol parameter conditions min typ max units v dd ic bias voltage 2.5 5.5 v v idac i dac operation voltage 0.4 2.0 v i dac output current range nominal, lsb = 1a C64 63 a range high, lsb = 4a C256 252 a range low, lsb = 0.25a C16 15.75 a a cc i dac accuracy nominal range C1.5 0.8 % dc2620aaf demo manual dc2620a-a
2 quick start procedure demonstration circuit 2620a -a makes it easy to use the? ltc7106 to adjust any conventional v fb referenced regulator and evaluate its performances. refer to figure?1 for the system setup and boards connection. connecting a pc and a regulator to dc2620a-a you can use a pc to reconfigure the power management features of the ltc7106 such as: program idac cur - rent, margin idac high/low, read back idac value and check fault status. the dc1613 a dongle may be plugged in regardless of whether v in is present. dongle can be hot?plugged. dc2620a-a can adjust the output voltage of any v fb ref - erenced regulator. use a twisted wire pair to connect the idac and gnd pins of dc2620 a-a to v fb and gnd pins of the regulator board. figure 1. demo setup with pc follow the procedure below: 1. make sure jp3 is in off position to disable the ltc7106 before turning on the regulator. 2. turn on the regulator and check for the output voltage as expected. 3. once the proper output voltage is established on the regulator, put jp3 to the on position to enable the ltc7106. 4. open the ltpowerplay software and adjust the idac current value of the ltc7106 through it. monitor the regulator s output voltage as idac is changing. see ltpowerplay quick start session for details 2620 0 ad 2620 2 6 2 usb cable 12-pin connector v in fcd a dc2620aaf demo manual dc2620a-a
3 quick start procedure figure 2 shows an application diagram using the ltc7106 with a typical dc/dc voltage regulator. by connecting idac to the feedback node of the voltage regulator, idac can change the output voltage of the regulator with the equation: v o u t = v r e f 1 + r f b 1 r f b 2 ? ? ? ? ? ? ? ? ? ? C i d a c ? r f b 1 where v ref is the reference voltage of the voltage regula - tor. r fb1 and r fb2 are the resistor divider for the voltage regulator. idac is the programmed bidirectional current of the ltc7106. figure 2. an application diagram using the ltc7106 with a typical dc/dc voltage regulator in order to achieve the best idac current accuracy of the ltc7106, its recommended to carefully design the volt - age divider so that the ltc7106 uses its nominal range. a design tool has been developed to help customers opti- mize their design. it s built in the ltpowercad ? software tool and can be downloaded from: http://www.linear.com/solutions/ltpowercad pmbus interface ?64 a to 0 a 0 a to 63 a dc2620a-a f02 dc2620aaf demo manual dc2620a-a c1 330f l1 r4 10k ltc7106 v dd gnd idac sda scl alert 1f gpo asel0 asel1 v dd 2.5v to 5.5v sda alert scl v dd v in dc/dc 10k sw v fb v out run en (0.4v to 2v) v in v ref 10k r3 r1 10k r2 r fb1 r fb2 c2
4 figure 3. ltpowerplay main interface for ltc7106 ltpowerplay is a powerful windows-based develop - ment environment that supports analog devices power system management ics, including the lt c3880 , ltc3883, ltc3882, ltc3815, ltc2974 and ltc2978. the software supports a variety of different tasks. you can use?ltpowerplay to evaluate analog devices ics by connecting to a demo board system. ltpowerplay utilizes the dc1613a usb-to-smbus controller to com - municate with one of many potential targets, including ltpowerplay software gui the lt c7106 s dc2620 a-a demo system, or a customer board. the software also provides an automatic update feature to keep the software current with the latest set of device drivers and documentation. the ltpowerplay software can be downloaded from: http://www.linear.com/ltpowerplay to access technical support documents for adi digi - tal?power products visit help. view online help on the ltpowerplay menu. dc2620aaf demo manual dc2620a-a
5 the following procedure describes how to use ltpow - erplay to monitor and change the settings of ltc7106. 1. download and install the ltpowerplay gui : http://www.linear.com/ltpowerplay 2. launch the ltpowerplay gui. a. the gui should automatically identify the dc2620a-a. the system tree on the left-hand side should look like this: ltpowerplay quick start procedure b. a blue message box shows for a few seconds in the lower left-hand corner, confirming that the ltc7106 is communicating: c. in the toolbar, click the r icon (ram to pc) to read the ram from the ltc7106. this reads the configuration from the ram of ltc7106 and loads it into the gui. when first powering on, you should read idac current at zero (high impedance idac) due to the ltc7106 s internal power-on reset circuitry until a valid write takes place. the idac current value can be plotted in real time, shown in the following screenshot (at zero when first power - ing?on): dc2620aaf demo manual dc2620a-a
6 d. if you want to change the idac current to 10a for example, in the config tab, type 10 in the mfr_ iout_command_ltc7106: ltpowerplay quick start procedure then, click the w icon (pc to ram) to write these register values to the ltc7106. if the write is successful, you will see the following message: in the telemetry plot, you will see idac current value change to the commanding value: e. if you want to change the idac current to a negative value (meaning sinking current), you need to change the mfr_iout_max_ltc7106 to a negative value first (see data sheet for more details). dc2620aaf demo manual dc2620a-a
7 parts list item qty reference part description manufacturer/part number required circuit components 1 1 c1 cap., 1.0f, x5r, 10v, 10%, 0603 avx, 0603z d105 kat2a 2 1 c2 cap., 100pf, x7r, 25v, 5%, 0603 avx, 06033 c101 jat2a 3 4 r1, r5, r6, r9 res., 0?, 1/10w, 0603 vishay, crcw06030000z0ea 4 3 r2, r3, r7 res., 10k, 1%, 1/10w, 0603 koa speer, rk73h1 jtt d1002f 5 3 r10, r11, r12 res., 100?, 1%, 1/10w, 0603 nic, nrc06f1000trf 6 1 u1 ic, dac 7-bit current dac analog devices, LTC7106EDDB additional demo board circuit components 1 0 c3 cap., option, 0603 option 2 0 r4 res., option, 0603 option 3 0 jp4 conn., option option 4 0 j2 conn., option option hardware 1 8 e1, e2, e3, e4, e5, e6, e7, e8 test point, turret, 0.094", mtg. hole mill-max, 2501-2-00-80-00-00-07-0 2 1 j1 conn., hdr, shrouded, 2mm 6mm, 2mm , tht, vert fci, 98414-g06-12ulf 3 2 jp1, jp2 conn., hdr, male, 1mm 4mm, 2mm , tht, str wurth elektronik, 62000411121 4 1 jp3 conn., hdr., male, 1mm 3mm, 2mm , tht, str sullins connector solutions, nrpn031 paen-rc 5 1 lb1 label spec, demo board serial number brady, tht- 96-717-10 6 4 mp1, mp2, mp3, mp4 standoff, nylon, snap-on, 0.250" keystone, 8831 7 1 pcb1 pcb, dc2620a analog devices, 600-dc2620a 8 4 xjp1, xjp2, xjp3, xjp4 conn., shunt, female, 2 pos, 2mm wurth elektronik, 60800213421 dc2620aaf demo manual dc2620a-a
8 schematic diagram 5 5 4 4 3 3 2 2 1 1 d d c c b b a a note: unless otherwise specified 1. all resistors and capacitors are 0603 revision history eco rev description approved date [ j 03/21/17 2 prod version ic (u1) r4 r5 r6 -a -b LTC7106EDDB LTC7106EDDB-1 opt 0 698 0 [2] header j2 j1 r3 10k opt header opt jp4 [2] opt opt to dc590b or linduino dc2086c vdd vdd vdd vdd vdd vdd vdd vdd vdd vdd date: ic no. sheet of title: demo circuit schematic, approvals pcb des. app eng. 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 supplied for use with linear technology parts. scale = none www.linear.com size: n/a sku no. schematic no. and revision: pca bom: pca ass'y: 1 1 ` \ [ j 7-bit current dac with digital power system management 710-dc2620a_rev02 LTC7106EDDB-1(-b) LTC7106EDDB(-a) thursday, september 28, 2017 705-dc2620a_rev02 700-dc2620a_rev02 dc2620a date: ic no. sheet of title: demo circuit schematic, approvals pcb des. app eng. 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 supplied for use with linear technology parts. scale = none www.linear.com size: n/a sku no. schematic no. and revision: pca bom: pca ass'y: 1 1 ` \ [ j 7-bit current dac with digital power system management 710-dc2620a_rev02 LTC7106EDDB-1(-b) LTC7106EDDB(-a) thursday, september 28, 2017 705-dc2620a_rev02 700-dc2620a_rev02 dc2620a date: ic no. sheet of title: demo circuit schematic, approvals pcb des. app eng. 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 supplied for use with linear technology parts. scale = none www.linear.com size: n/a sku no. schematic no. and revision: pca bom: pca ass'y: 1 1 ` \ [ j 7-bit current dac with digital power system management 710-dc2620a_rev02 LTC7106EDDB-1(-b) LTC7106EDDB(-a) thursday, september 28, 2017 705-dc2620a_rev02 700-dc2620a_rev02 dc2620a r6 [2] jp3 on off en 1 3 2 jp2 asel0 vdd float gnd 1 3 2 4 r7 10k 1% e7 vdd r2 10k 1% e3 sda r9 0 c2 100pf r10 100 j1 [2] to dc1613a auxp 1 sda 2 gnd 3 scl 4 lgkpwr 5 alertb 6 gpio_1 7 outen_0 8 outen_1 9 gnd 10 auxscl 11 auxsda 12 r4 [2] e4 aux e5 idac e8 gpo jp4 on off gpoinv 1 3 2 r3 [2] e6 gnd e2 alertb c1 1.0uf r11 100 r5 [2] j2 [2] v+ 1 3.3v or 5v 2 gnd 3 sck/scl 4 miso 5 cs 6 mosi/sda 7 gnd 8 eesda 9 eevcc 10 eescl 11 eegnd 12 gnd 13 gpio_1 14 c3 opt r12 100 e1 scl r1 0 jp1 asel1 vdd float gnd 1 3 2 4 u1 LTC7106EDDB sda/sdi 1 scl/sclk 2 vdd 3 alertb/spim 4 gnd 5 idac 6 en 7 gpo 8 sdo/aselo 9 csb/asel1 10 sda scl aux alertb csb sdo sdo sda scl csb aux dc2620aaf demo manual dc2620a-a
9 information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. specifications subject to change without notice. no license is granted by implication or otherwise under any patent or patent rights of analog devices. dc2620aaf demo manual dc2620a-a
10 lt 1217 ? printed in usa ? analog devices, inc. 2017 esd caution esd (electrostatic discharge) sensitive device. charged devices and circuit boards can discharge without detection. although this product features patented or proprietary protection circuitry, damage may occur on devices subjected to high energy esd. therefore, proper esd precautions should be taken to avoid performance degradation or loss of functionality. legal terms and conditions by using the evaluation board discussed herein (together with any tools, components documentation or support materials, the evaluation board), you are agreeing to be bound by the terms and conditions set forth below ( agreement ) unless you have purchased the evaluation board, in which case the analog devices standard terms and conditions of sale shall govern. do not use the evaluation board until you have read and agreed to the agreement. your use of the evaluation board shall signify your acceptance of the agreement. this agreement is made by and between you ( customer) and analog devices, inc. (adi ), with its principal place of business at one technology way, norwood, ma 02062, usa. subject to the terms and conditions of the agreement, adi hereby grants to customer a free, limited, personal, temporary, non-exclusive, non-sublicensable, non-transferable license to use the evaluation board for evaluation purposes only. customer understands and agrees that the evaluation board is provided for the sole and exclusive purpose referenced above, and agrees not to use the evaluation board for any other purpose. furthermore, the license granted is expressly made subject to the following additional limitations: customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the evaluation board; and (ii) permit any third party to access the evaluation board. as used herein, the term third party includes any entity other than adi, customer, their employees, affiliates and in-house consultants. the evaluation board is not sold to customer; all rights not expressly granted herein, including ownership of the evaluation board, are reserved by adi. confidentiality. this agreement and the evaluation board shall all be considered the confidential and proprietary information of adi. customer may not disclose or transfer any portion of the evaluation board to any other party for any reason. upon discontinuation of use of the evaluation board or termination of this agreement, customer agrees to promptly return the evaluation board to adi. additional restrictions. customer may not disassemble, decompile or reverse engineer chips on the evaluation board. customer shall inform adi of any occurred damages or any modifications or alterations it makes to the evaluation board, including but not limited to soldering or any other activity that affects the material content of the evaluation board. modifications to the evaluation b oard must comply with applicable law, including but not limited to the rohs directive. termination. adi may terminate this agreement at any time upon giving written notice to customer. customer agrees to return to adi the evaluation board at that time. limitation of liability. the evaluation board provided hereunder is provided as is and adi makes no warranties or representations of any kind with respect to it. adi specifically disclaims any representations, endorsements, guarantees, or warranties, express or implied, related to the evaluation board including, but not limited to, the implied warranty of merchantability, title, fitness for a particular purpose or noninfringement of intellectual property rights. in no event will adi and its licensors be liable for any incidental, special, indirect, or consequential damages resulting from customer s possession or use of the evaluation board, including but not limited to lost profits, delay costs, labor costs or loss of goodwill. adi s total liability from any and all causes shall be limited to the amount of one hundred us dollars ($100.00). export. customer agrees that it will not directly or indirectly export the evaluation board to another country, and that it will comply with all applicable united states federal laws and regulations relating to exports. governing law. this agreement shall be governed by and construed in accordance with the substantive laws of the commonwealth of massachusetts (excluding conflict of law rules). any legal action regarding this agreement will be heard in the state or federal courts havin g jurisdiction in suffolk county, massachusetts, and customer hereby submits to the personal jurisdiction and venue of such courts. the united nations convention on contracts for the international sale of goods shall not apply to this agreement and is expressly disclaimed. dc2620aaf demo manual dc2620a-a
|
