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page 1 of 14 features ? demonstrates the capabilities of the ds2764 li+ battery monitor, including: ? temperature measurement ? voltage measurement ? current measurement ? current accumulation ? information storage ? identification ? overvoltage/undervoltage protection ? overcurrent/short circuit protection ? interfaces to the usb port of a pc running windows xp ? or older operating system evaluation kit contents 1 pc. tssop evaluation board 1 pc. ds9123o usb adapter 1 pc. rj-11 cable equipment needed 1. a pc running windows xp ? or older operating system and an available usb port. 2. cables with mini-grabber style clips or the ability to solder directly to connection pads. 3. a lithium-ion battery and a power supply and/or load circuit. index evaluation kit contents equipment needed introduction setup and installation board connections software installation selecting the com port program menus register windows program tabs real time meters data logging user memory pack information fuel gauging DS2764EVKIT+ li + battery monitor evaluation kit 19-4828; rev 9/09 www.maxim-ic.com windows xp is a registered trademark of microsoft corp. downloaded from: http:///
DS2764EVKIT+ 2 of 14 introduction the ds2764 evaluation kit (ev kit) makes perf ormance evaluation, software development, and prototyping with the ds2764 lithium-i on battery monitor easy. the eval uation board interfaces to a pc through a ds9123o usb port adapter and rj-11 cable connection. the ds2764 ev kit evaluation software gives the user complete control of a ll functions of the ds2764. separate control tabs allow the user access to all eeprom and ram memory locations, all control registers, and real-time updates of all monitored parameters. the software also incorporates a data logging feature to monitor a cell over time and fuel gauging algorithms to improve remaining capacity calculations based on specific cell characteristics. the evaluation board circuit is designed to provi de the ds2764 with accurate parameter measurements, allow the ds2764 to disable charging or discharg ing, and protect the ds2764 from esd damage. kit demonstration boards will vary as they are improved upon over time. for information on the demonstration board circuits refer to the indivi dual board datasheets lo cated online at www.maxim- ic.com. setup and installation board connections connections to the tssop demonstrati on board are best made either by so ldering directly to the pads or by using cables with mini-grabber clips. communicat ion to the tssop board can be accomplished either through the rj-11 jack by connecting the provided st andard six conductor rj-11 cord or by wiring directly to the sda, scl and pac- pads. in the latter case, the si ze of the board can be reduced by snapping off the rj-11 jack along the break line, see figure 1. to utiliz e the demonstration software, the sda, scl and pac- lines must be connected to the ds9123o communication bric k using either of the two methods described. the sda and scl weak pull up, vp, should not be connected when communicating through the ds9123o. when using a diffe rent communication interface, connect vp to b+ to activate 4.7k pull-ups on sda and scl. figure 1: communication connections figures 2a and 2b show the recommended circuits to simulate charging and discharging. the lithium-ion cell is connected between the b+ and b- pads. the battery charger/power supply or circuit load is connected between the p+ and p- pads. the evaluation so ftware can be run in eith er configuration as long as a cell is connected between the b+ and b- termin als providing a minimum of 2.5 volts to power the ds2764. some board versions also have connections for the ps pin. refer to the datasheet for the operation of this pin. leaving it unconnected does not interfere with the operation of the demonstration board. sda rj-11 break line p - scl b- vp b+ p+ ps downloaded from: http:///
DS2764EVKIT+ 3 of 14 figure 2a: charging circuit fig 2b: discharging circuit software installation to install the ds2764 ev kit soft ware, exit all programs currentl y running and download the latest revision at www.maxim-ic.com. un zip the compressed file and double click the setup.exe icon to begin the installation process. follow the prompts to complete the installation. the ds2764 ev kit software can be uninstalled in the add/remove programs tool in the control panel. after the installation is complete, open the ds2764k folder and run ds 2764k.exe or select ds2764k from the program menu. a splash screen c ontaining information about the evaluation kit appears as the program is being loaded. selecting the communication port the first time the software runs, the select preferen ces window appears. in th is window, select either serial port or usb communication a nd the port number; then hit ok. the ds2764 ev kit software saves this port selection and automatically uses the selectio n each time the program star ts. to change the port later, click the preferences option on the menu bar, sele ct port settings, and then select the appropriate port. to attempt to automatically locate the ds9123o , click the poll serial ports button. warning - automatically polling for the ds9123o can disrupt other devices connected to your computer?s com ports. menus several pull down menu options have been provided to simplify use of the ds2764 ev kit software for the user. their functions are in dividually detailed below. b+ p- p + ps battery + - DS2764EVKIT+ evaluation board sda power supply / battery charger load b- scl b+ p- p+ ps battery + - DS2764EVKIT+ evaluation board sda b- scl downloaded from: http:///
DS2764EVKIT+ 4 of 14 file menu the file menu allows the user to store information fr om a file direc tly into the devi ce setup, battery data, and fuel gauging data sections under the pack info tab or take the same pack information and store to a file. these functions do no t directly write or read the ds2764. it is still ne cessary for the user to store or recall this information to or from the device by issuing a write or read command under the pack info tab. registers menu the registers menu gives immediate access to all four status and functi on registers of the ds2764. selecting any of the registers will open an individua l control window giving the us er a description of each register bit and the ability to read or write it. see the status regi ster window example. status register the present state of all register bits are displayed immediatel y upon opening the register window. r/w locations contain a selection field to allow the user to determine their state. pr essing either the apply or ok button in the eeprom register or special featur e register windows will automatically update and read the corresponding register inside the ds2764. the pr otection and status registers have default values stored in user eeprom addresses 0x30h and 0x31h respectively. their windows contain extra options to write or read these locations i ndependently of their registers. downloaded from: http:///
DS2764EVKIT+ 5 of 14 preferences menu the preferences menu allows the user to change co m port settings at any tim e. edit preferences opens the select preferences window. see se lecting the communication port above. help menu selecting the about topic from the help menu w ill open a window containing information about the current revision of this program and dallas semiconductor. program tabs all functions of the program are divided under five tabs in the main program window. left click on the appropriate tab to move to the desired function page. located under the meters tab is all information on real-time updates measured by the ds2764: voltage, current, accumulated charge, temperature, alarms, and all error flags. the data log tab allows the user to store all real time information including protection register state to a file. the memory tab displays the contents of every register and memory location inside the ds2764 and allows the user to alter the data. the pack information tab gives the user the ability to assign a default device configuratio n and store that information to the ds2764 and/or a file. the fuel gauging tab uses the cell characteri zation information stored under pack info to maintain a high accuracy remaining capacity indicator. downloaded from: http:///
DS2764EVKIT+ 6 of 14 meters tab the meters screen displays the latest real-time m easurements of cell voltage, temperature, current and accumulated charge with both analog meter readouts and digital values. the sense resistor value used to calculate the current reading is shown in the current section. left click on it or go to the sense resistor sub-tab under pack info to change this value. the calibrate offset button in the current section allows the user to zero the current measurements under the conditi ons of their circuit. left clicking this button will begin the automatic calibration procedure. calib ration should be performed while the pack is disconnected and there is no current fl ow. the next 32 readings will be averaged and the offset eliminated by adjusting the current offset re gister (location 0x33h) automaticall y. the process takes approximately 20 seconds. the user can bring up the update current accumulato r window by left clicking the set acr button. this window allows the user to enter va lues for the current accumulator re gister and rated battery capacity in mah. rated battery capacity is used to determ ine full scale range on the charge remaining meter only. it has no effect on device operation. the present states of the charge control and discharg e control pins are shown at the bottom left of the window. these outputs are ac tive low and drive two control fets a llowing charging and discharging of the cell pack. the charge control pin can be controlled manually by le ft clicking the disable/enable charging button and will be forced high automatically by either an overvoltage or charge overcurrent condition. the discharge control pin can also be controlled manually w ith the disable/enable discharging button and will be forced high automati cally by either an undervoltage or discharge overcurrent condition. the present state of each of the four possible flag conditions (overvoltage, undervoltage, charge overcurrent, and discharge overcurrent) are represen ted by leds inside the voltage and current sections of th e window. the corresponding led will be green while the flag is in the cleared state. if conditions cause a flag to be trip ped, the led will turn red and a button will appear that downloaded from: http:///
DS2764EVKIT+ 7 of 14 allows the user to clear the flag provided clear c onditions have been met. if conditions for clearing the flag have not been met by the circuit, clicking the clear button will have no effect. datalog tab the datalog tab allows the user to see the ds2764? s parameter measurements graphed over time. there are separate sub-tabs for voltage, current, temperature, and accumulate d charge. each graph displays the last 500 data points collected by the ds2764 ev kit software. the sampling interval can be adjusted from as fast as possible to 15 minutes and can be adjust ed from the sampling interv al menu at the bottom of the window. the clear graphs button will clear all data fr om all four graphs, but does not reset the log to file function. the log to file sub-tab contains control information fo r storing all log data to an ascii file. the default filename is c:\ds2764k_datal og.txt, but can be modified in the filename text field. the log data button toggles data logging off and on. data will be stored at the same interv al selected for updating the graphs in the tab delimited format of ?time voltage current temperature ca protection register? for easy import into a spreadsheet. the most rece nt 50 samples are displa yed in the window for observation. warning - the log data function overwri tes previous file information. data previously stored in the file will be lost. downloaded from: http:///
DS2764EVKIT+ 8 of 14 memory tab the memory tab gives the user access to all 12 re gister and 40 eeprom bytes inside the ds2764. they are separated into four sub-tabs fo r convenience. any value can be modi fied by clicking in that address? text box and typing a new value in hexadecimal format . the write button will copy the entire block of data to the correspondin g location inside the ds2764 (scratchpa d ram on the eeprom blocks). the read button will update the entire block?s text boxes with data fr om the ds2764 (scratchpad ram on the eeprom blocks). sub-tabs displa ying any eeprom data wi ll also have copy a nd recall buttons to allow the user to transfer the data between sc ratchpad and eeprom memory internal to the ds2764. the permanently lock block 0/1/2 buttons will permanently store the data currently located in that block?s eeprom if the lock bit in the eeprom register is set. otherwise this button will do nothing. warning ? this data can never be changed once lock ed. verify your data firs t by issuing a recall and a read. downloaded from: http:///
DS2764EVKIT+ 9 of 14 pack information tab the pack information tab gives the pack manufacturer the ability to assign default register settings, device and sense resistor selection, and recommended manufacturer data and fuel gauging information. the device select sub-tab allows the user to choos e which 2-wire bus device to communicate with and allows the user to read the rom id programmed in to custom versions of the ds2764. clicking on the find slave address button will begin a search of all addresses on the 2-wire bus. the slave address of the device can be changed by entering a new slave a ddress and clicking the write slave address button. the device setup sub-tab shows the current state of all major features of the ds2764. all status indicators shown here dire ctly mirror their corres ponding bits in the protec tion, status, and special feature registers. clicking on any of the status indicators will open th e corresponding register window to allow editing. see register s menu above. the selectio n fields on the right hand side of the sub-tab set how the eeprom backup bits (locations 0x30h and 0x31h) will be programmed when the ds2764 is programmed with the pack information. downloaded from: http:///
DS2764EVKIT+ 10 of 14 the sense resistor select sub-tab allows the user to correct the curren t measurements if a different value of sense resistor is used. all ds2764s w ith an integrated sense resistor use 25m ? s. if the sense resistor is located externally, the user should select the external resistor radio butto n on this tab, then enter the value of the resistor in m ? s in the sense resistor value field and th en click the write sense resistor button. the find sense resistor button opens the find sense resistor window. the user can then determine the resistance by forcing a known current and measuri ng the voltage drop with the ds2764. the resistance value is stored with ? m ? resolution into the user eeprom of the device. the program uses this value to convert the voltage difference from the vsens+ a nd vsens- pins into milliamps. if this value does not match the value of the external resistor, current measurements will be inaccurate. the battery data and fuel gauging data sub-tabs demonstrate how the pack manufacturer can use the ds2764s eeprom fields to store relevant pack inform ation such as assembly date, chemistry, etc? the fuel gauging characterization data is used by the fu el gauging algorithms in the software. see the fuel gauging tab description below. clic king on the load default pack info button will enter example data downloaded from: http:///
DS2764EVKIT+ 11 of 14 into the information fields of the device setup, batte ry data, and fuel gauging data sub-tabs. to change any of this information, simply click on the desired text field and enter the new value. once all data is in the desired format, click on the write ds2764 butt on to copy it to the eepro m of the ds2764. this information can also be stored to a file and reca lled later using the load/save pack info buttons. memory map of pack information data 0x20 0x21 fuel gauging ? full point at 0 ? c 0x22 fuel gauging ? full point difference from 10 ? c to 0 ? c 0x23 fuel gauging ? full point difference from 20 ? c to 10 ? c 0x24 fuel gauging ? full point difference from 30 ? c to 20 ? c 0x25 fuel gauging ? full point difference from 40 ? c to 30 ? c 0x26 0x27 total accumulated discharge ? di vided by 20 to store in 2 bytes 0x28 0x29 fuel gauging - age scalar 0x2a fuel gauging ? time from break point to full at 0 ? c 0x2b fuel gauging ? time from break point to full at 20 ? c 0x2c fuel gauging ? time from break point to full at 40 ? c 0x2d fuel gauging ? time from empty to full at 0 ? c 0x2e fuel gauging ? time from empty to full at 20 ? c 0x2f fuel gauging ? time from empty to full at 40 ? c 0x30 cell chemistry manufacturer ce de 0x31 pmod rnaop swen ie 0x32 fuel gauging ? charge estimation break point in mah 0x33 current offset ? do not overwrite 0x34 sense resistor (1/4m ? resolution) 0x35 0x36 date code ? 2 bytes 0x37 fuel gauging ? standby empty point difference from 0 ? c to 10 ? c 0x38 fuel gauging ? standby empty point difference from 10 ? c to 20 ? c 0x39 fuel gauging ? standby empty point difference from 20 ? c to 30 ? c 0x3a fuel gauging ? standby empty point difference from 30 ? c to 40 ? c 0x3b fuel gauging ? active empty point difference from 0 ? c to 10 ? c 0x3c fuel gauging ? active empty point difference from 10 ? c to 20 ? c 0x3d fuel gauging ? active empty point difference from 20 ? c to 30 ? c 0x3e fuel gauging ? active empty point difference from 30 ? c to 40 ? c addresses 0x3f fuel gauging ? active empty point at 40 ? c the memory map above shows the format in which the data is stored within the de vice. all static data is stored in block 1 while data which might need to be updated is in block 0. the pack manufacturer can now permanently lock block 1 to maintain data in tegrity while leaving block 0 open for access by the host processor. downloaded from: http:///
DS2764EVKIT+ 12 of 14 fuel gauging tab the final program tab performs a hi gh accuracy calculation of remain ing cell capacity using dallas semiconductor?s fuel gauging algorithms. for this feat ure to function properly, cell characterization data must be stored in the ds2764?s user eeprom. see the pack information section above. if characterization data cannot be found, the fuel gauge will not start and an error message will be displayed. the relative capacity number represents what percentage of cell capacity is remaining based on present algorithm inputs such as te mperature, discharge rate , etc? this value is also reflected in the analog meter. the remaining cell capacity is also di splayed in terms of milliamp-hours and joules under absolute capacity and remaining energy respectively. the remaining run time is calculated using the run time power referenc e input from the user. instantaneous current measurements in the user?s app lication can vary greatly. by using a reference scalar instead of actual current and voltage measurements, the progr am produces a stable estimation of remaining run time. the user should enter the largest expected power draw from the device into the run time power reference field fo r the most accurate estimation. if this example were part of a fully integrated fuel gauging system, the algorithms would need to be updated by the host each time the cell was fully charged or discha rged in order to maintain long term accuracy. to simulate this, the user should click the empty or full buttons each time the monitored pack is completely charged or discharged. the empty button will reset the curre nt accumulator to the expected empty point based on present conditions. the full button will set the current accumulator the expected full point based on present conditions. the learn button will rese t the expected full point to the present current accumulator value and update the fuel gauging information in the ds2764?s user eeprom. in doing this, the algorithms ?learn? from prev ious results and are more accurate in the future. this tab gives an example only of fuel gauging. fo r more information on the process of high accuracy fuel gauging consult dallas semiconduc tor?s fuel gauging ap plication notes. downloaded from: http:///
DS2764EVKIT+ 13 of 14 downloaded from: http:///
DS2764EVKIT+ 14 of 14 revision history revision date description pages changed 9/09 changed the part number from ds2764k to DS2764EVKIT+. all downloaded from: http:///

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