DEMO MANUAL DC2620A-A LTC7106 A 7-Bit Current DAC with Digital PMBus Interface DESCRIPTION Demonstration circuit 2620A-A uses the LTC(R)7106, a precision, bidirectional, 7-Bit current DAC with PMBus interface and can be used to adjust the output voltage of any conventional VFB 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 provides three ranges of IDAC output current: Nominal Range (-64A to 63A), Range High (-256A to 252A) and Range Low (-16A 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. PERFORMANCE SUMMARY To explore the power system management features of the parts, download the GUI software LTpowerPlay(R) onto your PC and use ADI's I2C/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: 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. All registered trademarks and trademarks are the property of their respective owners. Specifications are at TA = 25C SYMBOL PARAMETER VDD IC Bias Voltage 2.5 5.5 V VIDAC IDAC Operation Voltage 0.4 2.0 V IDAC Output Current Range ACC IDAC Accuracy CONDITIONS MIN TYP MAX UNITS Nominal, LSB = 1A -64 63 A Range High, LSB = 4A -256 252 A Range Low, LSB = 0.25A -16 15.75 A Nominal Range -1.5 0.8 % Rev.B 1 DEMO MANUAL DC2620A-A QUICK START PROCEDURE Demonstration circuit 2620A-A makes it easy to use theLTC7106 to adjust any conventional VFB referenced regulator and evaluate its performances. Refer to Figure1 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 current, margin IDAC high/low, read back IDAC value and check fault status. The DC1613A dongle may be plugged in regardless of whether VIN is present. Dongle can be hotplugged. DC2620A-A can adjust the output voltage of any VFB referenced regulator. Use a twisted wire pair to connect the IDAC and GND pins of DC2620A-A to VFB and GND pins of the regulator board. 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 2.5V to 5.5V Power Supply (OPTIONAL) USB CABLE USB to 2 I C/PMBus Dongle DC1613A VIN 12-PIN CONNECTOR Demo Board DC2620A-A IDAC VFB GND GND VFB Referenced Regulator DC2620A-A F01 Figure1. Demo Setup with PC Rev. B 2 DEMO MANUAL DC2620A-A QUICK START PROCEDURE Figure2 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: R VOUT = VREF 1+ FB1 - IDAC * R FB1 R FB2 In order to achieve the best IDAC current accuracy of the LTC7106, it's recommended to carefully design the voltage divider so that the LTC7106 uses its nominal range. A design tool has been developed to help customers optimize their design. It's built into the toolbox of the LTpowerCAD(R) software tool and can be downloaded from: LTpowerCAD where VREF is the reference voltage of the voltage regulator. RFB1 and RFB2 are the resistor divider for the voltage regulator. IDAC is the programmed bidirectional current of the LTC7106. L1 VIN SW VIN VOUT RFB1 DC/DC VFB R4 10k 0A TO 63A C1 1F SDA PMBus INTERFACE (0.4V to 2V) RFB2 RUN VDD 2.5V TO 5.5V VREF C2 330F SCL ALERT 10k R3 10k R2 10k R1 VDD EN GPO -64A TO 0A SDA SCL LTC7106 ALERT IDAC GND ASEL0 ASEL1 DC2620A-A F02 VDD Figure2. An Application Diagram Using the LTC7106 with a Typical DC/DC Voltage Regulator Rev.B 3 DEMO MANUAL DC2620A-A LTpowerPlay SOFTWARE GUI LTpowerPlay is a powerful Windows-based development environment that supports Analog Devices power system management ICs, including the LTC3880, LTC3883, LTC3882, LTC3815, LTC2974 and LTC2978. The software supports a variety of different tasks. You can useLTpowerPlay to evaluate Analog Devices ICs by connecting to a demo board system. LTpowerPlay utilizes the DC1613A USB-to-SMBus controller to communicate with one of many potential targets, including the LTC7106's DC2620A-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: LTpowerPlay To access technical support documents for ADI DigitalPower Products visit Help. View online help on the LTpowerPlay menu. Figure3. LTpowerPlay Main Interface for LTC7106 Rev. B 4 DEMO MANUAL DC2620A-A LTpowerPlay QUICK START PROCEDURE The following procedure describes how to use LTpowerPlay to monitor and change the settings of LTC7106. 1.Download and install the LTPowerPlay GUI: 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: 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 poweringon): b.A blue message box shows for a few seconds in the lower left-hand corner, confirming that the LTC7106 is communicating: Rev.B 5 DEMO MANUAL DC2620A-A LTpowerPlay QUICK START PROCEDURE 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: In the Telemetry Plot, you will see IDAC current value change to the commanding value: 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: 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). Rev. B 6 DEMO MANUAL DC2620A-A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C1 CAP., 1.0F, X5R, 10V, 10%, 0603 AVX, 0603ZD105KAT2A 2 1 C2 CAP., 100pF, X7R, 25V, 5%, 0603 AVX, 06033C101JAT2A 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, RK73H1JTTD1002F 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 x 6mm, 2mm, THT, VERT FCI, 98414-G06-12ULF 3 2 JP1, JP2 CONN., HDR, MALE, 1mm x 4mm, 2mm, THT, STR WURTH ELEKTRONIK, 62000411121 4 1 JP3 CONN., HDR., MALE, 1mm x 3mm, 2mm, THT, STR SULLINS CONNECTOR SOLUTIONS, NRPN031PAEN-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 Rev.B 7 A B C D V+ 14 13 12 11 10 9 8 7 6 5 4 3 2 1 E3 AUX AUX SDA 2 12 11 10 9 8 7 6 5 4 3 E6 VDD [2] LTC7106EDDB LTC7106EDDB-1 -A -B 5 * ADDRESS IS SET BY USER. IC (U1) VERSION OPT 10K R3 698 OPT R4 1. ALL RESISTORS AND CAPACITORS ARE 0603 NOTE: UNLESS OTHERWISE SPECIFIED GND VDD E7 TO DC1613A AUXSDA AUXSCL GND OUTEN_1 OUTEN_0 GPIO_1 ALERTB LGKPWR SCL GND SDA 1 0 4 OPT OPT 0 R6 R1 0 VDD R5 ALERTB SCL AUXP J1 [2] E4 AUX SDA R10 100 SCL SDO R11 100 CSB SDA R12 100 TO LINDUINO DC2026C GPIO_1 GND EEGND EESCL EEVCC EESDA GND MOSI/SDA CS MISO SCK/SCL GND 3.3V or 5V J2 [2] E1 E2 ALERTB SCL 4 3 2 1 FLOAT GND* JP1 FLOAT GND* JP2 ALERTB/GPO_INV SCL/SCLK SDA/SDI CUSTOMER NOTICE STUFF OPT J2 JP4 [2] OFF ON 4 2 1 CSB/ASEL1 C1 1.0uF OFF OPT JP4 6 7 8 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SKU NO. SIZE: N/A SCALE = NONE DC2620A C3 OPT 1 4 3 2 JP3 R6 [2] [2] JP2 GND FLOAT E5 IDAC E8 GPO 4 3 2 ASEL0 1 VDD 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only OFF ON GND R4 [2] VDD DATE: 2 Tuesday, February 18, 2020 PCA BOM: 700-DC2620A_REV02 PCA ASS'Y: 705-DC2620A_REV02 1 SHEET 1 OF 710-DC2620A_REV04 SCHEMATIC NO. AND REVISION: 1 TITLE: DEMO CIRCUIT SCHEMATIC, 7-BIT CURRENT DAC WITH DIGITAL POWER SYSTEM MANAGEMENT 3 2 1 [2] JP1 FLOAT ASEL1 VDD 1 VDD EN VDD REVISION HISTORY DESCRIPTION DATE APPROVED PROD KH 02/18/20 R9 0 VDD R5 [2] C2 100pF 1% R7 10k SDO 10 CSB 9 2 ECO REV 4 U1 [2] APPROVALS IDAC EN GPO SDO/ASELO VDD LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A MI CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; PCB DES. HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO KH APP ENG. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT IC NO. PERFORMANCE OR RELIABILITY. CONTACT LINEAR LTC7106EDDB(-A) TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. LTC7106EDDB-1(-B) OPT STUFF J1 R3 [2] VDD GPOINV VDD R2 10k 1% VDD 3 3 VDD GND 8 5 5 A B C D DEMO MANUAL DC2620A-A SCHEMATIC DIAGRAM Rev. B DEMO MANUAL DC2620A-A Rev.B 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. 9 DEMO MANUAL DC2620A-A ESD Caution ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. 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