xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 1 characteristics subject to change without notice revision 1.0 XM3100 preliminary 3 or 4 cell li-ion smart battery pack module description the XM3100 module is a complete battery pack solution that features the xicor x3100 lithium ion battery protection and monitor ic. for use in battery packs consisting of 3 or 4 lithium-ion battery cells (10.8v or 14.4v packs) the x3100 provides over-voltage, under- voltage, and over-current protection circuitry, internal eeprom memory, an internal voltage regulator, and drive circuitry for switching external fet devices used to control cell charge, discharge, and cell voltage balancing. the XM3100 module provides all external devices needed to control the battery pack including a preprogrammed microcontroller. this microcontroller has a system management bus (smbus v.1.0) interface with operation compliant with the smart battery system 1.1 standard. the built in software on the XM3100 module provides coulomb counting algorithms that provide a basic battery gas gauging function. future versions of the board will offer more extensive gas gauging, cell balancing routines and pack history tracking. the XM3100 board has outputs for a separate display board containing ?ve leds and a puchbutton switch. this board is included with the XM3100. the leds and switch allow the battery pack user to check the state of charge without connecting the battery to the host. the leds turn on for a short period of time when the switch is pressed to show capacity as 10%, 30%, 50%, 70% or 90% of full charge. the XM3100 board can be tailored to meet speci?c customer requirements. the module over-voltage, over- current, and under-voltage levels are easily changed through programmable non-volatile bits. simple capacitor changes provide different protection time-out periods. specialized software routines can offer customized gas gauging. feature benefit ? complete solution for 3-4 cell li-ion battery pack ? minimal design effort required ? x3100 and microcontroller control ? safe, accurate and ?exible implementation. ? built-in gas gauge software ? no algorithms to develop ? general purpose microcontroller ? custom software modules add more gas gauge capability, cell balancing, history tracking. ? smbus interface/sbs 1.1 compliant ? conforms to industry smart battery standards pins cl1: battery cell 1 (+) cl2: battery cell 1 (-)/battery cell 2 (+) cl3: battery cell 2 (-)/battery cell 3 (+) cl4: battery cell 3 (-)/battery cell 4 (+) b-: battery cell 4 (-) p+: battery pack positive terminal p-: battery pack negaitve terminal smbd: smbus data line smbc: smbus clock line led10: 10-30% capacity indicator led30: 30-50% capacity indicator led50: 50-70% capacity indicator led70: 70-90% capacity indicator led90: 90-100% capacity indicator sw1: indicator led switch input vrgo: regulated 5v output to display board neg: negative terminal of battery (for thermistor) rth: thermistor connection (battery pack temperature)
XM3100 2 xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 characteristics subject to change without notice preliminary safety unit the safety unit of the x3100 provides four selectable over voltage levels for the li-ion cells. the default threshold is set to 4.2v +/-50mv. other selectable levels are: 4.25v, 4.3v and 4.35v. the over voltage detect time is 1 second. this can be changed by replacing a capacitor on the board. when an over voltage occurs, the charge fet is automatically turned off. when voltage drops below the over voltage threshold minus 200 mv the charge fet is automatically turned back on. the x3100 provides four selectable under voltage levels for the battery cells. the default level is 2.25v +/-100mv. other options are 1.95v, 2.05v, and 2.15v. the under voltage delay time is set to 1 second, but this can be changed by replacing a capacitor on the board. when the board goes into an under voltage condition, both fets on the board turn off and the pack electronics go into a sleep mode. the unit returns to normal operation when the charger is reconnected to the pack. the x3100 provides four selectable over current levels for the battery pack. these levels are 3.75a, 5a, 6.25a and 7.5a. these are accurate to +/-0.75a. the over current detect time is set to 10ms, but may be changed by replacing a capacitor on the board. smbus interface/smart battery system the smbus interface is compliant with the sbs 1.1 speci?cations. the following section describes the operation of the smart battery interface, features and operation. additional details on the sbs1.1 standards are available in the smart battery data speci?cation revision 1.1, december 11, 1998. battery commands manufacturer access (0x00) this command is functional, so a value written using this command can be read back at a later time. however, the value written does not affect nor control the operation of the module. remaining capacity alarm (0x01) this command sets or gets the low capacity alarm threshold. whenever "remaining capacity" falls below "low capacity", the XM3100 sends an alarm warning message to the host. a low capacity setting of 0 disables the alarm. x3100 spi port XM3100 block diagram r th m37515 uc analog port v rgo p- cl2 cl3 cl4 b- vrgo smbc smbus i/f cell4 optional p+ cl1 led10 led30 led50 led70 led90 sw1 rth neg smbd th
XM3100 3 xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 characteristics subject to change without notice preliminary remaining time alarm (0x02) this command sets or gets the remaining time alarm value. whenever "average time to empty" falls below "remaining time", the XM3100 sends an alarm warning message to the host. a remaining time setting of 0 disables the alarm. battery mode (0x03) battery mode selects the various operating modes of the battery and reports on the batterys capabilities and modes and ?ags minor conditions requiring attention. atrate (0x04) the atrate function is the ?rst half of a two function call- set. atrate supplies the charge or discharge value used with "atratetimetofull", "atratetimetoempty" and "atrateok" commands. these second commands determine how long the pack can supply the requested energy or if the pack can supply the energy for a speci?c period of time. atratetimetofull (0x05) this command returns the predicted time to fully charge the battery at the previously written atrate value. atratetimetoempty (0x06) this command returns the predicted time to fully discharge the battery at the previously written atrate value. atrateok (0x07) atrateok returns true or false response indicating if the battery can deliver the previously written value of additional energy for 10 seconds. temperature (0x08) this command returns the cell-packs internal temperature ( o k*10). voltage (0x09) this command returns the cell pack voltage (mv). current (0x0a) this command returns the current being supplied or accepted through the battery terminals (ma). average current (0x0b) the value is a one minute rolling average of the current being supplied or accepted through the battery terminals (ma). maxerror (0x0c) maxerror is the expected margin of error in the state of charge calculations. relativestateofcharge (0x0d) this command returns the predicted remaining capacity expressed as a percentage of fullchargecapacity. absolutestateofcharge (0x0e) this command returns the predicted remaining battery capacity expressed as a percentage of designcapacity. remainingcapacity (0x0f) this command returns the predicted remaining battery capacity. fullchargecapacity (0x10) this command returns the predicted pack capacity when it is fully charged. table 1. battery mode bits bit field value comments 0 internal charge controller 1 read only internal charge controller supported 1 primary battery support 1 read only the XM3100 supports the operation as either a primary or secondary. 2-6 reserved 7 condition flag 0 or 1 read only 0 = battery o.k. 1 = conditioning cycle requested. 8 charge controller enabled 0 (default) or 1 internal charge controller is disabled. 9 primary battery 0 (default) or 1 0 - battery operating in its secondary role 1 - battery operating in its primary role 10-12 reserved 13 alarm mode 0 (default) or 1 0 - enable alarm warning broadcasts 1 - disable broadcasts 14 charger mode 0 (default) or 1 0 - enable charge current & voltage broadcasts 1 - disable broadcasts 15 capacity mode 0 (default) or 1 0 = ma or mah 1 = 10mw or 10mwh
XM3100 4 xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 characteristics subject to change without notice preliminary runtimetoempty (0x11) this command returns the predicted remaining battery life at the present rate of discharge (minutes). averagetimetoempty (0x12) this command returns a rolling average of the predicted remaining battery life (minutes). averagetimetofull (0x13) this command returns a rolling average of the predicted remaining time until the battery pack reaches a full charge (minutes). batterystatus (0x16) this command returns the batterys status word which contains alarm and status bit ?ags. the bits are de?ned in table 2. all of the microcontroller charge and discharge control is dictated by the battery status flags, though they cannot override the x3100s protection features. charging is allowed if all of the following are true: charge controller enabled = 1(optional, set via smbus) bit15 - overcharged alarm = 0 bit14 - terminate charge alarm = 0 bit12 - overtemp alarm = 0 discharging is allowed if all of the following are true: primary battery = 1 (optional, set via smbus) bit11 - terminate discharge alarm = 0 bit4 - fully discharged = 0 cyclecount (0x17) this command returns the number of charge/discharge cycles the battery has experienced. a cycle is de?ned as an amount of discharge approximately equal to the value of designcapacity. designcapacity (0x18) the command returns the theoretical capacity of a new pack. designvoltage (0x19) this command returns the theoretical voltage of a new pack (mv). speci?cationinfo (0x1a) this command returns the version number of the smart battery speci?cation that the battery pack supports. it also reports the voltage, current and capacity scaling information for the pack. table 2. battery status bits status word condition alarm bits 0x8000 bit15 over charged alarm: always cleared if the device is no longer charging. set if a cell voltage exceeds 4.352v or if the x3100 ovds ?ag is set. 0x4000 bit14 terminate charge alarm: always cleared if no longer charging. set with the over charged alarm ?ag. 0x2000 reserved 0x1000 bit12 over temperature alarm: set if the temperature exceeds 70 o c and cleared below 55 o c. 0x0800 bit11 terminate discharge alarm: always cleared if the current is non-negative. set if a cell voltage is less than 2.560v or if the x3100 ocds ?ag is set. 0x0400 reserved 0x0200 bit9 remaining capacity alarm: set if remaining capacity drops below the alarm threshold. cleared when the remaining capacity rises above the alarm threshold. 0x0100 bit8 remaining time alarm: set if the average time to empty drops below the alarm threshold. cleared when the average time to empty rises above the alarm threshold. status bits 0x0080 initialized: fixed at 1 0x0040 bit6 discharging: set when the current value is negative. cleared when positive. 0x0020 bit5 fully charged: set when the x3100 ovds ?ag is set cleared when the relative state of charge drops below 100%. 0x0010 bit4 fully discharged: set when terminate discharge flag is set, cleared whe relative state of charge rises above 20%. 0x0000- 0x000f reserved table 2. battery status bits status word condition
XM3100 5 xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 characteristics subject to change without notice preliminary manufacturedate (0x1b) this command returns the date that the pack was manufactured. serialnumber (0x1c) this command returns the pack serial number. manufacturername (0x1d) this command returns the pack manufacturer. the XM3100 is programmed to return "xicor, inc." but the value can be reprogrammed to meet the pack manufacturers needs. devicename (0x21) this command returns the batterys name. the XM3100 is programmed to return the board part number, but the value can be reprogrammed to meet the pack manufacturers needs. devicechemistry (0x22) this command returns the value "lion" to indicate that the pack supports li-ion batteries. manufacturerdata (0x23) as speci?ed in the smart battery speci?cation, this is a read only command that returns a block of data from the battery pack. it is an optional command used for reading various parameters from the pack. the XM3100 does not use this command, but enhanced software could use it to read collected battery pack history, such as the number of deep cycles, violations of temperature or current rate extremes, and discharge patterns. battery charger messages the battery charger can set the battery mode bit 14 high and poll the battery pack to determine the battery charging requirements. the charger can request the battery charging current, charging voltage, and status periodically, but it must do so at intervals from 5 to 60 seconds. if the charger periodocally polls the pack it can disable the packs automatic broadcast of the charging current and charging voltage by setting the charger mode bit to one. charging current (0x14) when receiving this command, the XM3100 returns the the smart battery desired charging rate. this is based on the speci?c cells being used in the pack. charging voltage (0x15) when receiving this command, the XM3100 returns the the smart battery desired charging voltage (mv). this is based on the speci?c cells being used in the pack. battery critical messages whenever the XM3100 detects a critical condition, it beomes the master and sends an alarm waring message to both the smart battery charger and the smbus host, notifying them of the critical condition. alarmwarning or broadcasts (0x16) the alarmwarning message is sent by the XM3100, acting as a bus master device, to the charger and host. it is a warning that one or more alarm conditions exist. the alarm conditions are encoded as bit ?elds in the messsage. these bit ?elds match those of the battery status word. the alarm warning messages are disabled by setting the battery mode bit 13 high. in this case the host and charger need to poll the battery pack to determine the status. a broadcast (command 0x16) is sent by the battery pack to other components on the smbus. it occurs automatically when the battery mode bit 14 is set low. this broadcast occurs every 30 seconds and provides the charger with values for desired charge current and voltage. gas gauge the gas gauge software on the XM3100 board consists of a simple accumulation of current based on the reading of voltage across the sense resistor. the software makes use of the current sense ampli?er of the x3100 to improve the accuracy of the current reading over a wide dynamic range. the accumulated current value is placed in a gas gauge register consistant with the sbs 1.1 speci?cation. other computations required for the sbs speci?cation (such as atrate) are computed continuously. the gas gauge does not provide routines for automatic compensation of the gas gauge value based on temperature or current rate. gas gauge calculations there are a number of calculations associated with the gas gauge. brief descriptions provided below give additional information about the operation of the module. core parameters ? average current: this value is updated every 1.874 seconds. it averages 32 "fast average" current values.
XM3100 6 xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 characteristics subject to change without notice preliminary ? remaining capacity: every 59.97 seconds the aver- age current is converted to mah then (if positive) is added to the remaining capacity value and (if nega- tive) is subtracted from the remaining capacity value. miscellaneous parameters these parameters are updated continuously, but the effective update rate is every 59.97 seconds, due to their dependency on the remaining capacity value. ? full charge capacity: this is a simple comparison to remaining capacity. because of the gas gauge sim- plicity, this value cannot exceed design capacity. ? relative state of charge: this value is remaining capacity divided by full charge capacity. ? absolute state of charge: this value is remaining capacity divided by design capacity. ? cycle count; this is incremented on an excursion from less than 5% relative state of charge to greater than 90%. ? maximum error: this value is ?xed at 5%. time to commands these parameters are updated continuously, but the effective update rate is every 59.97 seconds, due to their dependency on the remaining capacity value. ? run time to empty: the remaining capacity is con- verted to ma-min and divided by the current value. ? average time to empty: the remaining capacity is converted to ma-min and divided by the average cur- rent. ? average time to full: the full charge capacity minus remaining capacity value is converted to ma-min and divided by the average current. ? at rate commands these parameters are updated continuously, but the effective update rate is every 59.97 seconds, due to their dependency on the remaining capacity value. ? at rate o.k.: remaining capacity is converted to ma- 10s and compared to the at rate current. no dis- charge rate or temperature compensation is used. ? at rate time to full: the full charge capacity minus remaining capacity value is converted to ma-min and divided by the at rate current. ? at rate time ro empty: the remaining capacity value is converted to ma-min adn divided by the at rate cur- rent value. cell balancing cell balancing is not provided on this version of the module. another version (XM3100cb) will provide the external fets and resistors required to balance the cells and the software to control the balancing. cell balancing is a mechanism that adjusts the voltages on the cells so they are all equal. this is usually done when the pack is fully or nearly fully charged. cell balancing can improve the pack capacity and extend the life of the cells.
XM3100 7 xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 characteristics subject to change without notice preliminary absolute maximum ratings *comment stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only and the functional operation of the device at these or any other conditions above those indicated in the operational sections of this speci?cation is not implied. exposure to absolute max- imum rating conditions for extended periods may affect device reliability. recommended operating conditions parameter min. max. unit storage temperature -55 125 o c dc output current 5 ma lead temperature (soldering 10 seconds) 300 o c battery voltage (b-) - 0.5 (b-) +27.0 v storage temperature -50 125 ?c temperature min. max. industrial C40 o c +85 o c supply voltage limits XM3100 6v to 24v dc operating characteristics (over the recommended operating conditions, unless otherwise speci?ed. description sym condition min typ max unit vcc supply current (1) icc1 normal operation 4 ma vcc supply current (1) icc2 power down 300 a vcc supply current (4) icc3 sleep mode 1 a cell over-voltage protection mode threshold v ov v ov =4.20v (default) (1) 4.15 4.20 4.25 v cell over-voltage protection mode release threshold v ovr v ov =4.20v (default) (1) v ov -0.2 v cell over-voltage detection time t ov c ov =0.1uf 0.511.5s cell under-voltage protection mode (sleep) threshold. v uv v uv =2.3v (default) (1) 2.20 2.30 2.40 v cell under-voltage protection mode release threshold v uvr v uv =2.3v (default) (1) vuv+0.7 v cell under-voltage detection time t uv c uv =0.1f 0.511.5s cell under-voltage release time t uvr c uv =0.1f 3.5 7 10.5 ms over-current mode detection voltage v oc v oc =0.1v (default) (1) 0.085 0.100 0.115 v over-current mode detection time t oc c oc =1nf 51015ms over-current mode release time t ocr c oc =1nf 51015ms load resistance over-current mode release condition 150 250 k w cell charge threshold voltage v ce v ce =1.4v (default) (1) 1.30 1.40 1.50 v initial charger voltage (pack wake-up) v slr 16.0 17.0 v
XM3100 8 xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 characteristics subject to change without notice preliminary equivalent a.c. load circuit a.c. test conditions a.c. characteristics (over recommended operating conditions, unless otherwise speci?ed) sda 1533 w 100pf 5v for v ol = 0.4v and i ol = 3 ma input pulse levels 0.1v cc to 0.9v cc input rise and fall times 10ns input and output timing levels 0.5v cc output load standard output load symbol parameter 100khz min max units v il smbdata, smbclk input low voltage -0.5 0.6 v v ih smbdata, smbclk input high voltage 1.4 5.5 v v ol smbdata, smbclk output low voltage (@i pullup , max) 0.4 v i peak input leakage 5 a i pullup current through pullup resistor or current source 100 350 a f smb smbus operating frequency 10 100 khz t buf bus free between stop and start condition 4.7 s t hd:sta hold time after (repeated) start condition. after this period, the ?rst clock is generated. 4.0 s t su:sta repeated start condition setup time 4.7 s t su:sto stop condition setup time 4.0 s t hd:dat data hold time 300 ns t su:dat data setup time 250 ns t timeout clock low timeout 25 35 ms t low clock low time 4.7 s t high clock high time 4.0 50 s t low:sext cumulative clock low extend time (slave device) 25 ms t low:mext cumulative clock low extend time (master device) 10 ms t r clock/data rise time 1000 ns t f clock/data fall time 300 ns
XM3100 9 xicor, inc. 1994 C 1999 patents pending preliminary revision 5.0 characteristics subject to change without notice preliminary bus timing valid start and stop conditions acknowledge response from receiver t su:sto t high t su:sta t hd:sta t hd:dat t su:dat smbc smbd t f t low t buf t r smbc smbd start stop smbd from transmitter smbd from receiver 8 1 9 start acknowledge smbc from transmitter
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