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To Download TEXASINSTRUMENTSINC-BQ2092SN-A311 Datasheet File |
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| features ? provides accurate measure - ment of available charge in nicd, nimh, and li-ion re - chargeable batteries ? supports sbdata charge con - trol commands for li-ion, nimh, and nicd chemistries ? designed for battery pack inte - gration - 120 a typical operating current - small size enables implementations in as little as 3 4 square inch of pcb ? two-wire smbus-like interface ? measurements compensated for current and temperature ? programmable self-discharge and charge compensation ? 16-pin narrow soic general description the bq2092 gas gauge ic with smbus-like interface is intended for battery-pack or in-system instal - lation to maintain an accurate record of available battery charge. the bq2092 directly supports capac - ity monitoring for nicd, nimh, and li-ion battery chemistries. the bq2092 uses the smbus proto - col that supports many of the smart battery data (sbdata) commands. the bq2092 also supports sbdata charge control. battery state-of- charge, capacity remaining, remain - ing time and chemistry are available over the serial link. battery-charge state can be directly indicated using a four-segment led display to graphically depict battery full-to- empty in 25% increments. the bq2092 estimates battery self- discharge based on an internal timer and temperature sensor and user-programmable rate informa - tion stored in external eeprom. the bq2092 also automatically recalibrates or ?learns? battery capacity in the full course of a discharge cycle from full to empty. the bq2092 may operate directly from three nickel chemistry cells. with the ref output and an exter - nal transistor, a simple, inexpensive regulator can be built to provide v cc for other battery cell configurations. an external eeprom is used to program initial values into the bq2092 and is necessary for proper operation. 1 bq2092 gas gauge ic with smbus-like interface v cc 3.0?5.5v scl serial memory clock sda serial memory data seg 1 led segment 1 seg 2 led segment 2 seg 3 led segment 3 seg 4 led segment 4 v ss system ground 1 pn209101.eps 16-pin narrow soic 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 v out ref scc scd nc sb disp sr v cc scl sda seg 1 seg 2 seg 3 seg 4 v ss sr sense resistor input disp display control input sb battery sense input scd serial communication data input/output scc serial communication clock ref voltage reference output v out eeprom supply output 6/99 c pin connections pin names
pin descriptions v cc supply voltage input scl serial memory clock this output is used to clock the data transfer between the bq2092 and the ex - ternal nonvolatile configuration memory. sda serial memory data and address this bi-directional pin is used to trans - fer address and data to and from the bq2092 and the external configuration memory. seg 1 ? seg 4 led display segment outputs each output may activate an external led to sink the current sourced from v cc . v ss ground sr sense resistor input the voltage drop (v sr ) across pins sr and v ss is monitored and integrated over time to interpret charge and discharge activity. the sr input is connected to the sense re- sistor and the negative terminal of the battery. v sr functional description general operation the bq2092 determines battery capacity by monitoring the amount of charge input to or removed from a rechargeable battery. the bq2092 measures discharge and charge currents, estimates self-discharge, and monitors the battery for low-battery voltage thresh - olds. the charge measurement is made by monitoring the voltage across a small-value series sense resistor between the battery's negative terminal and ground. the available battery charge is determined by moni - toring this voltage over time and correcting the meas - urement for the environmental and operating condi - tions. figure 1 shows a typical battery pack application of the bq2092 using the led capacity display, the serial port, and an external eeprom for battery pack program - ming information. the bq2092 must be configured and calibrated for the battery-specific information to ensure proper operation. table 1 outlines the externally programmable functions available in the bq2092. refer to the programming the bq2092 section for further details. an internal temperature sensor eliminates the need for an external thermistor?reducing cost and compo - nents. an internal, temperature-compensated time- base eliminates the need for an external resonator, further reducing cost and components. the entire circuit in figure 1 can occupy less than 3 4 square inch of board space. 3 bq2092 v cc scl sda seg1 seg2 seg3 seg4 v out ref scc scd nc sb disp sr bzx84c5v6 bzx84c5v6 2192l.eps figure 1. battery pack application diagram?led display 4 parameter name address length units design capacity 0x00/0x01 16 bits: low byte, high byte mah initial battery voltage 0x02/0x03 16 bits: low byte, high byte mv fast charging current 0x04/0x05 16 bits: low byte, high byte ma charging voltage 0x06/0x07 16 bit: low byte, high byte mv remaining capacity alarm 0x08/0x09 16 bits: low byte, high byte mah flags1 0x0a 8 bits n/a flags2 0x0b 8 bits n/a current measurement gain 0x0c/0x0d 16 bits: low byte, high byte n/a edv 1 0x0e/0x0f 16 bits: low byte, high byte mv edv f 0x10/0x11 16 bits: low byte, high byte mv temperature offset 0x12 8 bits 0.1k maximum charge temperature/ ? t/ ? t 0x13 8 bits n/a self-discharge rate 0x14 8 bits n/a digital filter 0x15 8 bits n/a current integration gain 0x16/0x17 16 bits: low byte, high byte n/a full charge percentage 0x18 8 bits n/a charge compensation 0x19 8 bits n/a battery voltage offset 0x1a 8 bits mv battery voltage gain 0x1b/0x1c 16 bits: high byte, low byte n/a serial number 0x1d/0x1e 16 bits: low byte, high byte n/a hold-off timer 0x1f 8 bits n/a cycle count 0x20/0x21 16 bits: low byte, high byte n/a maintenance charge current 0x22/0x23 16 bits: low byte, high byte ma reserved 0x24/0x31 ? ? design voltage 0x32/0x33 16 bits: low byte, high byte mv specification information 0x34/0x35 16 bits: low byte, high byte n/a manufacturer date 0x36/0x37 16 bits: low byte, high byte n/a reserved 0x38/0x3f ? ? manufacturer name 0x40/0x4f 8 + 120 bits n/a device name 0x50/0x5f 8 + 120 bits n/a chemistry 0x60/0x6f 8 + 120 bits n/a manufacturer data 0x70/0x7f 8 +120 bits n/a table 1. configuration memory programming values note: n/a = not applicable; data packed or coded. see ?programming the bq2092? for details. bq2092 voltage thresholds in conjunction with monitoring v sr for charge/discharge currents, the bq2092 monitors the battery potential through the sb pin. the voltage potential is deter - mined through a resistor-divider network per the following equation: r r mbv 2.25 5 4 1 =? where mbv is the maximum battery voltage, r 5 is connected to the positive battery terminal, and r 4 is connected to the negative battery terminal. r 5 /r 4 should be rounded to the next highest integer. the voltage at the sb pin (v sb ) should never exceed 2.4v. the battery voltage is monitored for the end-of- discharge voltage (edv), for maximum pack voltage and for alarm warning conditions. edv threshold levels are used to determine when the battery has reached an ?empty? state, and the charging voltage plus 5% thresh - old is used for fault detection during charging. the battery voltage gain, two edv thresholds, and charge voltage limit are programmed via eeprom. see the programming the bq2092 section for further details. if v sb is below either of the two edv thresholds, the associ- ated flag is latched and remains latched, independent of v sb , until the next valid charge. edv monitoring may be disabled under certain condi- tions. if the discharge current is greater than approxi- mately 6a, edv monitoring is disabled and resumes after the current falls below 6a. reset the bq2092 is reset when first connected to the battery pack. the bq2092 can also be reset with a command over the serial port, as described in the software reset section. temperature the bq2092 monitors temperature using an internal sensor. the temperature is used to adapt charge/dis - charge and self-discharge compensations as well as maximum temperature and ? t/ ? t during bq2092 con - trolled charge. temperature may also be accessed over the serial port. see the programming the bq2092 section for further details. layout considerations the bq2092 measures the voltage differential between the sr and v ss pins. v os (the offset voltage at the sr pin) is greatly affected by pc board layout. for optimal results, the pc board layout should follow the strict rule of a single-point ground return. sharing high-current ground with small signal ground causes undesirable noise on the small signal nodes. additionally, in refer - ence to figure 1: the capacitors (c1, c2, and c4) should be placed as close as possible to the sb and v cc pins, and their paths to v ss should be as short as possible. a high-quality ceramic capacitor of 0.1 f is recommended for v cc . the sense resistor capacitor (c3) should be placed as close as possible to the sr pin. the sense resistor (r1) should be as close as possible to the bq2092. the ic should be close to the cells for the best temperature measurement. an optional zener may be necessary to ensure v cc is not above the maximum rating during operation. gas gauge operation the operational overview diagram in figure 2 illus- trates the operation of the bq2092. the bq2092 accumu- lates a measure of charge and discharge currents, as well as an estimation of self-discharge. charge currents are compensated for temperature and state-of-charge. self-discharge is only temperature-compensated. the main counter, remainingcapacity (rm), represents the available battery capacity at any given time. battery charging increments the rm register, whereas battery discharging and self-discharge decrement the rm register and increment the discharge count register (dcr). the discharge count register (dcr) is used to update the fullchargecapacity (fcc) register only if a complete battery discharge from full to empty occurs without any partial battery charges. therefore, the bq2092 adapts its capacity determination based on the actual conditions of discharge. the battery's initial capacity is equal to the designcapacity (dc). until fcc is updated, rm counts up to, but not beyond, this threshold during subsequent charges. 1. fullchargecapacity or learned-battery capacity: fcc is the last measured discharge capacity of the battery. on initialization (application of v cc or reset), fcc = dc. during subsequent discharges, the fcc is updated with the latest measured capacity in the discharge count register, representing a discharge from full to below edv1. a qualified discharge is necessary for a capacity transfer from the dcr to the fcc register. the fcc also serves as the 100% ref - erence threshold used by the relative state-of-charge calculation and display. 5 bq2092 2. designcapacity (dc): the dc is the user-specified battery capacity and is programmed by using an external eeprom. the dc also provides the 100% reference for the abso- lute display mode. 3. remaining capacity (rm): rm counts up during charge to a maximum value of fcc and down during discharge and self-discharge to 0. rm is reset to 0000ah when edv 1 = 1 and a valid charge is detected. to prevent overstatement of charge during periods of overcharge, rm stops in- crementing when rm = fcc. rm may optionally be written to a user-defined value when fully charged when the battery pack is under bq2092 charge control. see the charge control section for further details. 4. discharge count register (dcr): the dcr counts up during discharge independent of rm and can continue increasing after rm has decremented to 0. before r m = 0 (empty battery), both discharge and self-discharge incre ment the dcr. after rm = 0, only discharge in crements the dcr. the dcr resets to 0 when rm = fcc. the dcr does not roll over but stops counting when it reaches ffffh. the dcr value becomes the new fcc value on the first charge after a valid discharge to v edv1 if: no valid charge initiations (charges greater than 10mah, where v sro >|v srd |) occurred during the period between rm = fcc and edv1 de - tected. the self-discharge count is not more than 256mah. the temperature is 273k (0c) when the edv1 level is reached during discharge. the valid discharge flag (vdq) indicates whether the present discharge is valid for fcc update. fcc cannot be reduced by more than 256mah during any single cycle. charge counting charge activity is detected based on a positive voltage on the v sr input. if charge activity is detected, the bq2092 increments rm at a rate proportional to v sro and, if enabled, activates an led display. charge actions increment the rm after compensation for charge rate and temperature. the bq2092 determines charge activity sustained at a continuous rate equivalent to v sro >|v srd |. a valid charge equates to sustained charge activity greater than 10 mah . once a valid charge is detected, charge counting continues until v sro falls below |v srd |. v srd is a programmable threshold as described in the digital magnitude filter section. discharge counting all discharge counts where v sro <|v srd | cause the rm register to decrement and the dcr to increment. v srd is a programmable threshold as described in the digital magnitude filter section. self-discharge estimation the bq2092 continuously decrements rm and incre - ments dcr for self-discharge based on time and temperature. the self-discharge rate is dependent on the battery chemistry. the bq2092 self-discharge esti - mation rate is externally programmed in eeprom 6 bq2092 rate and temperature compensation temperature compensation charge current discharge current self-discharge timer remaining capacity (rm) full charge capacity (fcc) discharge count register (dcr) < qualified transfer + temperature, other data + - - + inputs main counters and capacity reference (fcc) outputs two-wire serial interface chip-controlled available charge led display rate and temperature compensation figure 2. operational overview and can be programmed from 0 to 25% per day at 20-30c. this rate doubles every 10c increase until t >70 c or is halved every 10 decrease unti lt<10 c. the self-discharge estimate reduces rm by 0.39% of its current value at time intervals spaced so that the aver - age reduction equals the programmed value adjusted for temperature. the eeprom program constant is the 2?s complement of 52 73 . x , where xday = % self-discharge rate desired at 25 c. charge control the bq2092 supports sbd charge control by broadcast - ing chargingcurrent() and chargingvoltage() to the smart charger address. smart charger broadcasts can be disabled by writing bit 14 of battery mode() to 1. the bq2092-based charge control can be enabled by setting bit 4 in flags2 (msb of 0x2f) to 1. see programming the bq2092 for further details. if the fully_charged bit is not set in batterystatus, the bq2092 broadcasts the fast charge current and voltage to the smart charger. the bq2092 broadcasts the maintenance current values (trickle rate) if the fully_charged bit is set or voltage is below edvf. the bq2092 internal charge control is compatible with nickel-based and li-ion chemistries. for li-ion, the bq2092 broadcasts the required charg- ingcurrent and chargingvoltage according to the values programmed in the external eeprom. during a valid charge (vq = 1), the bq2092 signals a valid charge termination when the terminate_charge_alarm and fully_charged bits are set in batterystatus. these bits are set when the battery is charged more than 256mah above fcc. for nickel-based chemistries, the bq2092 broadcasts the required charge current and voltage according to the programmed values in the external eeprom. maxi - mum temperature and ? t/ ? t are used as valid charge termination methods. note: nickel-based chemistries require a charge voltage higher than the maximum cell voltage during charge to ensure constant-current charg - ing. during a valid charge (vq = 1), if the bq2092 deter - mines a maximum temperature condition, a ? t/ ? t rate greater than the programmed value, or a charge state greater than 256mah above fcc, then the termi - nate_charge_alarm, over_charge_alarm, and fully_charged bits are set in batterystatus. once the bq2092 detects a valid charge termination, the fully_charged bit, terminate_charge_alarm, and over_charge_alarm bits are set and the chargingcurrent is set to zero. once the terminating condition ceases, the terminate_charge_alarm and overcharge alarm bits are cleared and the chargingcurrent is set to the maintenance rate. the bq2092 requests the maintenance current and charging voltage until rm falls below the full charge percentage. once this occurs, the fully_charged bit is cleared, and the bq2092 requests the fast charging current and charging voltage. during fast charge, the bq2092 suspends charge by requesting zero current and setting the termi - nate_charge_alarm bit in batterystatus. charge is suspended if the actual charge current is 25% greater than the programmed charged current. if the programmed charge current is less than 1024ma, over - current suspend occurs if the actual charge current is 256ma greater than the programmed value. charge is also suspended if the actual battery voltage is 5% greater than the programmed charge voltage. if the battery temperature is greater than the programmed maximum temperature before charge, then the bq2092 suspends charge requests until the temperature falls below 50c. if the battery temperature is less than 0c, the charging current sets to maintenance (trickle) charge current. the fast charging current is requested when the temperature is above 5 c. ? t/ ? t the ? t/ ? t used by the bq2092 is programmable in both the temperature step (1.6 c?4.6 c) and time step (20 seconds?320seconds). typical settings for 1 c/min include 2 c over 120 seconds and 3 c over 180 seconds. longer times are required for increased slope resolution. ? ? t t is set by the formula: ? ? t t = () [] lower nibble of 0 13 in e prom lower nibble 2 ??+ 216 2' s () [] of 0 1f in e prom c minute 2 ?? ? ? ? ? ? ? 333 . o in addition to the ? t/ ? t timer, there is a hold-off timer, which starts when the battery is being charged at more than 256ma and the temperature is above 25 c. (this is valid only for nimh chemistry, bit 5 in flags2 set to 0.) until this timer expires, ? t/ ? t is suspended. if the temperature falls below 25 c, or if charging current fallls below 255ma, the timer is reset and restarts only if the above conditions are once again met. safety termination if charging continues for more than 256mah beyond rm = fcc, the terminate_charge_alarm and fully_charged bits are set, and the charging current is modified to request maintenance current. if the battery is discharged from full by less than 256mah, then the safety overcharge termination, for nimh only, is allowed to extend to 512 mah. updating rm after a valid charge termination, rm may optionally be set to a value from 0 to 100% of the full - chargecapacity. if rm is below the value programmed 7 bq2092 in full charge percentage, rm is set to full charge percentage of fcc on valid charge termination. if rm is above the full charge percentage, rm is not modified. count compensations charge activity is compensated for temperature and state-of-charge before updating the rm and/or dcr. rm is compensated for temperature before updating the rm register. self-discharge estimation is compensated for temperature before updating rm or dcr. charge compensation charge efficiency is compensated for state-of-charge, temperature, and battery chemistry. for li-ion chemis - try cells, the charge efficiency is unity for all cases. the charge efficiency for nickel chemistry cells, however, is adjusted using the following equation: rm rm q q efc et =? ? () where relativestateofcharge fullchargepercentage and q efc is the programmed fast charge efficiency vary- ing from .75 to .99. rm rm q q etc et =? ? () where relativestateofcharge fullchargepercentage and q etc is the programmed maintenance (trickle) charge efficiency varying from 0.50 to 0.97. q et is used to adjust the charge efficiency as the battery temperature increases according to the following: qift et =< 030 c qctc et =< 002 30 40 .if qtc et =? 005 40 .if remaining capacity compensation the bq2092 adjusts the rm as a function of tempera - ture. this adjustment accounts for the reduced capacity of the battery at colder temperatures. the following equation is used to adjust rm: if t c ? 5 remainingcapacity nominal available capacity (nac) = if t < 5c rm() nac() tcc t 5 c)) =+?? (( 1 where t = temperature c tcc = 0.004 rm adjusts upward to nominal available capacity as the temperature increases. digital magnitude filter the bq2092 has a programmable digital filter to elimi - nate charge and discharge counting below a set threshold. table 2 shows typical digital filter settings. the proper digital filter setting can be calculated using the following equation. |v srd (mv)| = 45 / dmf error summary capacity inaccurate the fcc is susceptible to error on initialization or if no updates occur. on initialization, the fcc value includes the error between the design capacity and the actual capacity. this error is present until a valid discharge occurs and fcc is updated (see the dcr description on page 6). the other cause of fcc error is battery wear- out. as the battery ages, the measured capacity must be adjusted to account for changes in actual battery capac - ity. periodic discharges from full to empty will mini - mize errors in fcc. current-sensing error table 3 illustrates the current-sensing error as a func - tion of v sr . a digital filter eliminates charge and discharge counts to the rm register when v sro is between v srq and v srd . display the bq2092 can directly display capacity information using low-power leds. the bq2092 displays the battery charge state in either absolute or relative mode. in rela - tive mode, the battery charge is represented as a percentage of the fcc. each led segment represents 25% of the fcc. 8 bq2092 dmf dmf hex. |v srd (mv)| 75 4b 0.60 100 64 0.45 150 (default) 96 0.30 175 af 0.26 200 c8 0.23 table 2. typical digital filter settings in absolute mode, each segment represents a fixed amount of charge, 25% of the design capacity. as the battery wears out over time, it is possible for the fcc to be below the design capacity. in this case, all of the leds may not turn on in absolute mode, representing the reduction in the actual battery capacity. the displayed capacity is compensated for the present battery temperature. the displayed capacity varies as temperature varies, indicating the available charge at the present conditions. when disp is tied to v cc , the seg 1?4 outputs are inac- tive. when disp is left floating, the display becomes active whenever the bq2092 detects a charge rate of 100ma or more. when pulled low, the segment outputs become active immediately for a period of approximately 4 seconds. the disp pin must be returned to float or v cc to reactivate the display. the segment outputs are modulated as two banks of two, with segments 1 and 3 alternating with segments 2 and 4. the segment outputs are modulated at approximately 100hz with each segment bank active for 30% of the period. seg 1 blinks at a 4hz rate whenever v sb has been detected to be below v edv1 (edv 1 = 1), indicating a low- battery condition. v sb below v edvf (edv f = 1) disables the display output. microregulator the bq2092 can operate directly from three nickel chem - istry cells. to facilitate the power supply requirements of the bq2092, an ref output is provided to regulate an external low-threshold n-fet. a micropower source for the bq2092 can be inexpensively built using the fet and an external resistor; see figure 1. note that an optional zener diode may be necessary to limit v cc during charge. communicating with the bq2092 the bq2092 includes a simple two-pin (scc and scd) bidirectional serial data interface. a host processor uses the interface to access various bq2092 registers; see table 4. this allows battery characteristics to be easily monitored. the open-drain scd and scc pins on the bq2092 are pulled up by the host system, or may be connected to v ss , if the serial interface is not used. the interface uses a command-based protocol, where the host processor sends the battery address and an eight- bit command byte to the bq2092. the command directs the bq2092 to either store the next data received to a register specified by the command byte or output the data specified by the command byte. bq2092 data protocols the host system, acting in the role of a bus master, uses the read word and write word protocols to communicate integer data with the bq2092. (see figure 3.) host-to-bq2092 message protocol the bus host communicates with the bq2092 using one of three protocols: read word write word read block the particular protocol used is a function of the command. the protocols used are shown in figure 3. host-to-bq2092 messages (see table 4) manufactureraccess() (0x00) this optional function is not operational for the bq2092. remainingcapacityalarm() (0x01) this function sets or returns the low-capacity alarm value. when rm falls below the remainingcapac - ityalarm value, the remaining_capacity_alarm bit is set in batterystatus (0x16). the system may alter this alarm value during operation. 9 symbol parameter typical maximum units notes v os offset referred to v sr 50 150 v disp = v cc . inl integrated non-linearity error 2 4 % add 0.1% per c above or below 25c and 1% per volt above or below 4.25v. inr integrated non- repeatability error 1 2 % measurement repeatability given similar operating conditions. table 3. bq2092 current-sensing errors bq2092 10 function code access units defaults 1 manufactureraccess 0x00 read/write - - remaningcapacityalarm 0x01 read/write unsigned int. e 2 remainingtimealarm 0x02 read/write unsigned int. 10 batterymode 0x03 read/write bit flag - temperature 0x08 read 0.1k - voltage 0x09 read mv - current 0x0a read ma 0000h averagecurrent 0x0b read ma 0000h maxerror 0x0c read percent 100 relativestateofcharge 0x0d read percent 0000h absolutestateofcharge 0x0e read percent 0000h remainingcapacity 0x0f read mah 0000h fullchargecapacity 0x10 read mah e 2 runtimetoempty 0x11 read minutes - averagetimetoempty 0x12 read minutes - reserved 0x13 - - - chargingcurrent 0x14 read ma e 2 chargingvoltage 0x15 read mv e 2 batterystatus 0x16 read number 0000h cyclecount 0x17 read count e 2 designcapacity 0x18 read mah e 2 designvoltage 0x19 read mv e 2 specificationinfo 0x1a read number e 2 manufacturedate 0x1b read unsigned int e 2 serialnumber 0x1c read number e 2 reserved 0x1d - 0x1f - - - manufacturername 0x20 read string e 2 devicename 0x21 read string e 2 devicechemistry 0x22 read string e 2 manufacturerdata 0x23 read string e 2 flags1 and flags2 0x2f read bit flag e 2 endof dischargevoltage1 0x3e read mv e 2 endofdischargevoltagefinal 0x3f read mv e 2 note: 1. defaults after reset or power-up. table 4. bq2092 register functions bq2092 11 fg209202.eps s battery address 0001011 0 a command code a data byte low a data byte high ap 1 1 8 1 8 1 8 1 1 7 1 s battery address 0001011 0 a command code a battery address a 1 1 1 7 1 8 1 1 7 1 s 1 aa 1 8 1 8 p data byte low data byte high s battery address 0001011 0x16 0 a command code a battery address a 1 1 1 7 1 8 1 1 7 1 s 1 aa 1 8 1 8 byte count =n data byte 1 aa 1 8 1 8 p data byte 2 data byte n 1 bq2092 system host block read read word write word a ? acknowledge a ? not acknowledge s ? start p ? stop figure 3. host communication protocols bq2092 input/output: unsigned integer. this sets/re - turns the value where the remaining ca - pacity alarm bit is set in batterystatus. remainingtimealarm() (0x02) this function sets or returns the low remaining time alarm value. when the averagetimetoempty (0x12) falls below this value, the remaining_time_alarm bit in batterystatus is set. the default value for this register is set in eeprom. the system may alter this alarm value during operation. input/output: unsigned integer. this sets/returns the value where the remaining_time_alarm bit is set in batterystatus . batterymode() (0x03) this read/write word selects the various battery opera - tional modes. the bq2092 supports the battery capacity information specified in mah. this function also deter - mines whether the bq2092 charging values are broad - casted to the smart battery charger address. writing bit 14 to 1 disables voltage and current smart battery charger messages. bit 14 is reset to 0 once the pack is removed from the system (scc and scd = 0 for greater than 2 seconds.) writing bit 13 to 1 disables all smart battery charger messages including alarm messages. this bit remains set until overwritten. programming bit 3 of flags2 in eeprom (ee 0x0b) initializes bit 13 of batterymode to 1. temperature() (0x08) this read-only word returns the cell-pack's internal temperature (0.1k). output: unsigned integer. returns cell tempera - ture in tenths of degrees kelvin increments units: 0.1k range: 0 to +500.0k granularity: 0.5k or better accuracy: 3k after calibration voltage() (0x09) this read-only word returns the cell-pack voltage (mv). output: unsigned integer. returns battery terminal voltage in mv units: mv range: 0 to 65,535 mv granularity: 0.2% of designvoltage accuracy: 1% of designvoltage after calibration current() (0x0a) this read-only word returns the current through the battery's terminals (ma). output: signed integer. returns the charge/dis - charge rate in ma, where positive is for charge and negative is for discharge units: ma range: 0 to 32,767 ma for charge or 0 to ?32,768 ma for discharge granularity: 0.2% of the designcapacity or better accuracy: 1% of the designcapacity after calibration averagecurrent() (0x0b) this read-only word returns a rolling average of the current through the battery's terminals. for the bq2092 current = averagecurrent. the averagecurrent func- tion returns meaningful values after the battery's first minute of operation. output: signed integer. returns the charge/dis- charge rate in ma, where positive is for charge and negative is for discharge units: ma range: 0 to 32,767 ma for charge or 0 to ?32,768 ma for discharge granularity: 0.2% of the designcapacity or better accuracy: 1% of the designcapacity after cali - bration maxerror() (0x0c) this read-only word returns the expected margin of error (%). output: unsigned integer. returns percent uncer - tainty units: % range: 0 to 100% relativestateofcharge() (0x0d) this read-only word returns the predicted remaining battery capacity expressed as a percentage of fullchar - gecapacity (%). relativestateofcharge is only valid for battery capacities less than 10,400mah. output: unsigned integer. returns the percent of re - maining capacity 12 bq2092 units: % range: 0 to 100% granularity: 1% absolutestateofcharge() (0x0e) this read-only word returns the predicted remaining battery capacity expressed as a percentage of designca - pacity (%). note that absolutestateofcharge can return values greater than 100%. absolute stateofcharge is only valid for battery capacities less than 10,400mah . output: unsigned integer. returns the percent of remaining capacity. units: % range: 0 to 65,535 % granularity: 1% or better accuracy: maxerror remainingcapacity() (0x0f) this read-only word returns the predicted remaining battery capacity. the remainingcapacity value is expressed in mah. output: unsigned integer. returns the estimated re- maining capacity in mah. units: mah range: 0 to 65,535 mah granularity: 0.2% of designcapacity or better fullchargecapacity() (0x10) this read-only word returns the predicted pack capacity when it is fully charged. fullchargecapacity defaults to the value programmed in the external eeprom until a new pack capacity is learned. output: unsigned integer. returns the estimated full charge capacity in mah. units: mah range: 0 to 65,535 mah granularity: 0.2% of designcapacity or better runtimetoempty() (0x11) this read-only word returns the predicted remaining battery life at the present rate of discharge (minutes). the runtimetoempty() value is calculated based on current(). output: unsigned integer. returns the minutes of operation left. units: minutes range: 0 to 65,534 minutes granularity: 2 minutes or better invalid data indication: 65,535 indicates battery is not being discharged averagetimetoempty() (0x12) this read-only word returns the predicted remaining battery life at the present average discharge rate (minutes). the averagetimetoempty is calculated based on averagecurrent. output: unsigned integer. returns the minutes of operation left. units: minutes range: 0 to 65,534 minutes granularity: 2 minutes or better invalid data indication: 65,535 indicates battery is not being charged chargingcurrent() (0x14) if enabled, the bq2092 sends the desired charging rate in ma to the smart battery charger. output: unsigned integer. transmits/returns the maximum charger output current in ma. units: ma range: 0 to 65,534 ma granularity: 0.2% of the design capacity or better invalid data indication: 65,535 indicates that the smart charger should operate as a voltage source outside its maximum regulated current range. chargingvoltage() (0x15) if enabled, the bq2092 sends the desired voltage in mv to the smart battery charger. output: unsigned integer. transmits/returns the charger voltage output in mv. units: mv range: 0 to 65,534mv granularity: 0.2% of the designvoltage or better invalid data indication: 65,535 indicates that the smart battery charger should operate as a cur - 13 bq2092 rent source outside its maximum regulated voltage range. batterystatus() (0x16) this read-only word returns the batterystatus word. output: unsigned integer. returns the status reg - ister with alarm conditions bitmapped as shown in table 5. some of the batterystatus flags (remaining_capac - ity_alarm and remaining_time_alarm) are calculated based on current. see table 8 for definitions. cyclecount() (0x17) this read-only word returns the number of charge/discharge cycles the battery has experienced. a charge/discharge cycle starts from a base value equivalent to the battery's state-of-charge, on completion of a charge cycle. the bq2092 increments the cycle counter during the current charge cycle, if the battery has been discharged 15% below the state-of-charge at the end of the last charge cycle. this prevents false reporting of small charge/discharge cycles. output: unsigned integer. returns the count of charge/discharge cycles the battery has experienced. units: cycles range: 0 to 65,535 cycles; 65,535 indicates battery has experienced 65,535 or more cycles granularity: 1 cycle designcapacity() (0x18) this read-only word returns the theoretical capacity of a new pack. the designcapacity() value is expressed in mah at the nominal discharge rate. output: unsigned integer. returns the battery ca - pacity in mah. units: mah range: 0 to 65,535 mah designvoltage() (0x19) this read-only word returns the theoretical voltage of a new pack in mv. output: unsigned integer. returns the battery's normal terminal voltage in mv. units: mv range: 0 to 65,535 mv specificationinfo() (0x1a) this read-only word returns the specification revision the bq2092 supports. it is typically set to all zeros to represent non-rev 1.0 compliance to the smbus speci - fication output: unsigned integer. manufacturedate() (0x1b) this read-only word returns the date the cell was manu - factured in a packed integer word. the date is packed as follows: (year - 1980) ? 512 + month ? 32+day. field bits used format allowable value day 0?4 5-bit binary value 1?31 (corresponds to date) month 5?8 4-bit binary value 1?12 (corresponds to month number) year 9?15 7-bit binary value 0?127 (corresponds to year biased by 1980) serialnumber() (0x1c) this read-only word returns a serial number. this number, when combined with the manufacturername, the devicename, and the manufacturedate, uniquely identifies the battery. output: unsigned integer 14 bq2092 alarm bits 0x8000 overcharge_alarm 0x4000 terminate_charge_alarm 0x2000 reserved 0x1000 over_temp_alarm 0x0800 terminate_discharge_alarm 0x0400 reserved 0x0200 remaining_capacity_alarm 0x0100 remaining_time_alarm status bits 0x0080 initialized 0x0040 discharging 0x0020 fully_charged 0x0010 fully_discharged error code 0x0000- 0x000f reserved for error codes table 5. status register manufacturername() (0x20) this read-only string returns a character string where the first byte is the number of characters available. the maxi - mum number of characters is 15. the character string contains the battery manufacturer's name. for example, ?unitrode? identifies the battery pack manufacturer as unitrode. output: string or ascii character string devicename() (0x21) this read-only string returns a character string where the first byte is the number of characters available. the maxi - mum number of characters is 15. the 15-byte character string contains the battery's name. for example, a devicename of ?bq2092? indicates that the battery is a model bq2092. output: string or ascii character string devicechemistry() (0x22) this read-only string returns a character string where the first byte is the number of characters available. the maximum number of characters is 15. the 15-byte char- acter string contains the battery's chemistry. for exam- ple, if the devicechemistry function returns ?nimh,? the battery pack contains nickel-metal hydride cells. output: string or ascii character string manufacturerdata() (0x23) this read-only string allows access to an up to 15-byte manufacturer data string. output: block data?data whose meaning is as - signed by the smart battery's manufacturer. endofdischargevoltage1() (0x3e) this read-only word returns the first end-of-discharge voltage programmed for the pack. output: two?s complemented unsigned integer. re - turns battery end-of-discharge voltage pro - grammed in eeprom in mv. endofdischargevoltagef() (0x3f) this read-only word returns the final end-of-discharge voltage programmed for the pack. output: two?s complemented unsigned integer. returns battery final end-of-discharge voltage pro - grammed in eeprom in mv. flags1&2() (0x2f) this read-only register returns an unsigned integer representing the internal status registers of the bq2092. the msb represents flags2, and the lsb represents flags1. see table 6 for the bit description for flags1 and flags2. flags2 the display mode flag (dmode), bit 7, determines whether the bq2092 displays relative or absolute capac - ity. the dmode values are: flags2 bits 7 6543210 dmode - - - - - - - where dmode is: 0 selects absolute display 1 selects relative display bit 6 is reserved. the chemistry flag (chm), bit 5, selects li-ion or nickel compensation factors. the chm values are: flags2 bits 76 5 43210 - - chm - - - - - 15 bq2092 (msb) 7 6543210 (lsb) flags2 dmode - chm cc - ov ltf oc flags1 - - vq wrinh vdq sedv edv1 edvf note: - = reserved table 6. bit descriptions for flags1 and flags2 where chm is: 0 selects nickel 1 selects li-ion bit 4, the charge control flag (cc), determines whether a bq2092-based charge termination will set rm to a user-defined programmable full charge capacity. the cc values are: where cc is: 0 rm is not modified on valid bq2092 charge termination 1 rm is set to a programmable percentage of the fcc when a valid bq2092 charge termi - nation occurs bit 3 is reserved. bit 2, the overvoltage flag (ov), is set when the bq2092 detects a pack voltage 5% greater than the programmed charging voltage. this bit is cleared when the pack volt- age falls 5% below the programmed charging voltage. the ov values are: where ov is: 0 batteryvoltage() < 1.05 ? chargingvoltage 1 batteryvoltage() 1.05 ? chargingvoltage bit 1, the low temperature fault flag (ltf), is set when temperature < 0c and cleared when temperature > 5c. the ltf values are: where ltf is: 0 temperature > 5c 1 temperature < 0c bit 0, the overcurrent flag (oc), is set when the average current is 25% greater than the programmed charging current. if the charging current is programmed less than 1024ma, overcurrent is set if the average current is 256ma greater than the programmed charging current. this flag is cleared when the average current falls below 256ma. the oc values are: where oc is: 0 average current is less than 1.25 ? charg - ing current or less than 256ma if charging current is programmed less than 1024ma 1 average current exceeds 1.25 ? charging current or 256ma if the charging current is programmed less than 1024ma. this bit is cleared if average current < 256ma flags1 bits 7 and 6 are reserved. the valid charge flag (vq), bit 5, is set when v sro |v srd | and 10mah of charge has accumulated. this bit is cleared during a discharge and when v sro |v srd |. the vq values are: where vq is: 0v sro |vsrd | 1v sro |v srd | and 10mah of charge has accumulated the write inhibit flag (wrinh), bit 4, allows or inhibits writes to all registers. the wrinh values are: where wrinh is: 0 allows writes to all registers 1 inhibits all writes and secures the bq2092 from invalid/undesired writes. 16 bq2092 flags2 bits 76 5 43210 - - - - -ov- - flags2 bits 765432 1 0 ------ - oc flags1 bits 76 5 43210 -- vq ----- flags1 bits 765 4 3210 - - - wrinh ---- flags2 bits 76 5 43210 -- - cc---- wrinh should be set at the time of pack assembly and tested to prevent special read-write registers from acci - dental over-writing. the valid discharge flag (vdq), bit 3, is set when a valid discharge is occurring (discharge cycle valid for learning new full charge capacity) and cleared if a partial charge is detected, edv1 is asserted when t < 0c, or self-discharge accounts for more than 256mah of the discharge. the vdq values are: where vdq is: 0 self-discharge is greater than 256mah, edv1 = 1 when t < 0c or vq = 1 1 on first discharge after rm=fcc the stop edv flag (sedv), bit 2, is set when the discharge current > 6.15a and cleared when the discharge current falls below 6.15a. the sedv values are: where sedv is: 0 current < 6.15a 1 current > 6.15a the first end-of-discharge voltage flag (edv1), bit 1, is set when voltage < edv1 = 1 if sed v = 0 and cleared when v q = 1 and voltage > edv1. the edv1 values are: where edv1 is: 0 vq = 1 and voltage > edv1 1 voltage < edv1 and sedv = 0 the final end-of-discharge voltage flag (edvf), bit 0, is set when voltage < edv f=1ifsedv=0andc leared when v q = 1 and voltage() > edvf. the edvf values are: where edvf is: 0 vq = 1 and voltage > edvf 1 voltage < edvf and sedv = 0 software reset the bq2092 can be reset over the serial port by confirm - ing that the wrinh bit is set to zero in flags1, writ - ing maxerror (0x0c) to any value other than 2, and writ - ing the reset register (0x44) to 8009, causing the bq2092 to reinitialize and read the default values from the external eeprom. error codes and status bits error codes and status bits are listed in table 7 and table 8, respectively. programming the bq2092 the bq2092 requires the proper programming of an external eeprom for proper device operation. each module can be calibrated for the greatest accuracy, or general ?default? values can be used. a programming kit (interface board, software, and cable) for an ibm- compatible pc is available from unitrode. please contact unitrode for further details the bq2092 uses a 24lc01 or equivalent serial eeprom for storing the various initial values, calibra - tion data, and string information. table 1 outlines the parameters and addresses for this information. tables 9 and 10 detail the various register contents and show an example program value for an 1800mah nimh battery pack, using a 50m ? sense resistor. 17 bq2092 flags1 bits 76543 2 10 - - - - - sedv - - flags1 bits 765432 1 0 - - - - - - edv1 - flags1 bits 7654 3 210 - - - - vdq - - - flags1 bits 7654321 0 - - - - - - - edvf 18 error code access description ok 0x0000 read/write bq2092 processed the function code without detecting any errors busy 0x0001 read/write bq2092 is unable to process the function code at this time notready 0x0002 read/write bq2092 cannot read or write the data at this time?try again later unsupportedcommand 0x0003 read/write bq2092 does not support the requested function code accessdenied 0x0004 write bq2092 detected an attempt to write to a read-only function code overflow/underflow 0x0005 read/write bq2092 detected a data overflow or underflow badsize 0x0006 write bq2092 detected an attempt to write to a function code with an incorrect size data block unknownerror 0x0007 read/write bq2092 detected an unidentifiable error note: reading the bq2092 after an error clears the error code. table 7. error codes (batterystatus() (0x16)) bq2092 19 alarm bits bit name set when: reset when: over_charge_alarm bq2092 detects over-temperature or ? t/ ? t. ( note: valid charge termina - tion ). a discharge occurs or when ? t/ ? t, or over-temperature, ceases during charge. terminate_charge_alarm bq2092 detects over-current, over- voltage, over-temperature, or ? t/ ? t conditions exist during charge. charging current is set to zero, indi - cating a charge suspend. a discharge occurs or when all condi - tions causing the event cease. ? t/ ? t_alarm bq2092 detects the rate-of- temperature increase is above the pro - grammed value (valid termination) the temperature rise falls below the programmed rate. over_temp_alarm bq2092 detects that its internal tem - perature is greater than the pro - grammed value (valid termination). internal temperature falls below 50c. terminate_discharge_alarm bq2092 determines that it has sup- plied all the charge that it can with- out being damaged (edvf). v bat > v edvf signifying that the battery has reached a state of charge sufficient for it to once again safely supply power. remaining_capacity_alarm bq2092 detects that the remaining- capacity() is less than that set by the remainingcapacity() function. either the value set by the remain- ingcapacityalarm() function is lower than the remaining capacity() or the remainingcapacity() is in- creased by charging. remaining_time_alarm bq2092 detects that the estimated remaining time at the present dis- charge rate is less than that set by the remainingtimealarm() function. either the value set by the remain- ingtimealarm() function is lower than the averagetimetoempty() or a valid charge is detected. status bits bit name set when: reset when: initialized bq2092 is set when the bq2092 has reached a full or empty state. battery detects that power-on or user-initiated reset has occurred. discharging bq2092 determines that it is not be - ing charged. battery detects that it is being charged. fully_charged bq2092 determines a valid charge termination. rm will then be set to full charge percentage if necessary. rm discharges below the full charge percentage fully_discharged bq2092 determines that it has supplied all the charge that it can without being damaged (that is, con - tinued use will result in permanent capacity loss to the battery) relativestateofcharge is greater than or equal to 20% table 8. status bits bq2092 20 description eeprom address eeprom hex contents example values notes low byte high byte low byte high byte design capacity 0x00 0x01 08 07 1800mah this sets the initial full charge battery capacity stored in fcc. fcc is updated with the actual full to empty discharge capacity after a valid discharge from rm = fcc to voltage() = edv1. initial battery voltage 0x02 0x03 30 2a 10800mv this register is used to set the battery voltage on reset. fast charging current 0x04 0x05 08 07 1800ma this register is used to set the fast charge current for the smart charger. fast charging voltage 0x06 0x07 c4 3b 15300mv this register is used to set the fast charge voltage for the smart charger. remaining capacity alarm 0x08 0x09 b4 00 180mah this value represents the low capacity alarm value. flags1 0x0a 10 flags1 should be set to 10h before pack shipment to inhibit undesirable writes to the bq2092. (wrinh = 1.) flags2 0x0b 90 li-ion = b0h nimh = 90h see flags2 register for the bit description and the proper value for programming flags2. selects rela- tive display mode, selects nimh compensation factors, and enables bq2092 smart charger control. current measurement gain 1 0x0c 0x0d ee 02 37.5/.05 the current gain measurement and current integration gain are related and defined for the bq2092 current measurement. 0x0c = 37.5/sense resistor value in ohms. edv1 0x0e 0x0f 16 db 9450mv (1.05v/cell) the value programmed is the two's complement of the threshold voltage in mv. edvf 0x10 0x11 d8 dc 9000mv (1.0v/cell) the value programmed is the two's complement of the threshold voltage in mv. note: 1. can be adjusted to calibrate the battery pack. table 9. example register contents bq2092 21 description eeprom address eeprom hex contents example values notes low byte high byte low byte high byte temperature offset 1 0x12 32 5.0c the default value is 0x80 (12.8 + nominal value). actual temp (20c) = nominal temp. (15c) - temp. offset (5c) where temperature determined by the bq2092 can be adjusted from 0 to 25.5 (tempera - ture offset (0-255) ? 0 .1) + nominal value temp. maximum charge temperature, ? temp. 0x13 87 maxt = 61.2c (74 - (8 * 1.6)) ? t = 3c ((7*2) + 16)/10 maximum charge temperature is 74 - (mt x 1.6)c (mt = upper nibble). the ? t step is (dt*2+16)/10c (dt = lower nibble). self- discharge rate 0x14 dd 1.5% this packed field is the two's complement of 52.73/x, where x = %/day is the self-discharge rate desired at room temperature. digital filter 0x15 96 0.3mv this field is used to set the digital magnitude filter as described in table 2. current integration gain 1 0x16 0x17 40 00 3.2/0.05 this field represents the following: 3.2/sense resis- tor in ohms. it is used by the bq2092 to scale the measured voltage values on the sr pin in ma and mah. this register also compensates for variations in the reported sense resistor value. full charge percentage 0x18 a0 96% = 60h 2?s (60h) = a0h this packed field is the two?s complement of the desired value in rm when the bq2092 determines a full charge termination. if rm is below this value, rm is set to this value. if rm is above this value, then rm is not adjusted. charge compensation 0x19 bd 85% = mainte - nance comp. 95% = fast charge comp. this packed value is used to set the fast charge and maintenance charge efficiency for nickel-based batter - ies. the upper nibble adjusts the maintenance charge compensation; the lower nibble adjusts the fast charge compensation. maintenance, upper nibble = (eff% ? 256 - 128)/8 fast charge, lower nibble = (eff% ? 256 - 192)/4 battery voltage offset 1 (v off ) 0x1a 0a 10mv this value is used to adjust the battery voltage offset according to the following: voltage () = (v sb (mv) + v off ) ? voltage gain voltage gain 1 0x1b 0x1c 09 17 9.09 voltage gain is packed as two units. for example, (r 4 + r 5 )/r 4 = 9.09 would be stored as: whole num - ber stored in 0x1b (=09h) and the decimal compo - nent stored in 0x1c as 256 x 0.09 = 23. serial number 0x1d 0x1e 12 27 10002 this contains the optional pack serial number. table 9. example register contents (continued) bq2092 22 bq2092 description eeprom address eeprom hex contents example values notes low byte high byte low byte high byte hold-off timer/ ? time 0x1f 07 320 s hold-off 180 s ? time hold-off time is 20 s ? the two?s complement of the upper nibble value. ? t is 20 s ? the two?s comple - ment of the lower nibble value. charge cycle count 0x20 0x21 00 00 0 this field contains the charge cycle count and should be set to zero for a new battery. maintenance charge current 0x22 0x23 64 00 100ma this field contains the desired maintenance current after fast charge termination by the bq2092. reserved 0x24 0x31 design voltage 0x32 0x33 30 2a 10800mv this is nominal battery pack voltage. specification information 0x34 0x35 00 00 this is the default value for this register. manufacturer date 0x36 0x37 a1 20 may 1, 1996 = 8353 packed per the manufacturedate description, which represents may 1, 1996 in this example. table 9. example register contents (continued) string description ad dress 0x x0 0x x1 0x x2 0x x3 0x x4 0x x5 0x x6 0x x7 0x x8 0x x9 0x xa 0x xb-xf reserved 0x38- 0x3f 00 00 00 00 00 00 00 00 00 00 00 00-00 manufacturer's name 0x40- 0x4f 09 42 b 45 e 4e n 43 c 48 h 4d m 41 a 52 r 51 q 00 00-00 device name 0x50- 0x5f 08 42 b 51 q 32 2 30 0 39 9 32 2 41 a 33 3 31 1 31 1 00-00 chemistry 0x60- 0x6f 04 4e n 69 i 4d m 48 h 00 00 00 00 00 00 00-00 manufacturer's data 0x70- 0x7f 04 44 d 52 r 31 1 35 5 00 00 00 00 00 00 00-00 table 10. example register contents (string data) 23 absolute maximum ratings symbol parameter minimum maximum unit notes v cc relative to v ss -0.3 +7.0 v all other pins relative to v ss -0.3 +7.0 v ref relative to v ss -0.3 +8.5 v current limited by r1 (see figure 1) v sr relative to v ss -0.3 +7.0 v minimum 100 ? series resistor should be used to protect sr in case of a shorted battery (see the bq2092 appli - cation note for details). t opr operating tempera - ture 0 +70 c commercial note: permanent device damage may occur if absolute maximum ratings are exceeded. functional opera - tion should be limited to the recommended dc operating conditions detailed in this data sheet. expo - sure to conditions beyond the operational limits for extended periods of time may affect device reliability. dc voltage thresholds (t a =t opr ; v = 3.0 to 5.5v) symbol parameter minimum typical maximum unit notes e vsb battery voltage error relative to sb -50mv - 50mv v see note note: the accuracy of the voltage measurement may be improved by adjusting the battery voltage offset and gain, stored in external eeprom. for proper operation, v cc should be 1.5v greater than v sb . bq2092 24 recommended dc operating conditions (t a = t opr ) symbol parameter minimum typical maximum unit notes v cc supply voltage 3.0 4.25 5.5 v v cc excursion from < 2.0v to 3.0v initializes the unit. v ref reference at 25c 5.7 6.0 6.3 v i ref = 5 a reference at -40c to +85c 4.5 - 7.5 v i ref = 5 a r ref reference input impedance 2.0 5.0 - m ? v ref = 3v - 90 135 av cc = 3.0v i cc normal operation - 120 180 av cc = 4.25v - 170 250 av cc = 5.5v v sb battery input 0 - v cc v r sbmax sb input impedance 10 - - m ? 0 < v sb < v cc i disp disp input leakage - - 5 av disp = v ss i lvout v out output leakage -0.2 - 0.2 a eeprom off v sr sense resistor input -0.3 - 2.0 v v sr 25 symbol parameter min max units notes f smb smbus operating frequency 10 100 khz t buf bus free time between stop and start condition 4.7 s t hd:sta hold time after (repeated) start condition 4.0 s t su:sta repeated start condition setup time 250 ns scd 4.7 s external memory t su:sto stop condition setup time 4.0 s t hd:dat data hold time 1 s t su:dat data setup time 250 ns t ext1 data buffering time addresses 40 ms 0x19, 0x1a, 0x1b t ext2 string buffering time addresses 0x20-0x23 per character 15 ms 40ms for first character t pd data output delay time 300 3500 ns external memory only. see note. t low clock low period 4.7 s t high clock high period 4.0 s t f clock/data fall time 300 ns t r clock/data rise time 1000 ns note: the external memory must provide this internal minimum delay time to bridge the undefined region (minimum 300 ns) of the falling edge of scl to avoid unintended generation of start or stop conditions. ac specifications td209201.eps t su:sta scc scd t su:sto t buf t hd:sta t low t su:dat t r t f t high t hd:dat t pd (receiver) (transmitter) bus timing data bq2092 26 bq2092 16-pin soic narrow (sn) a a1 .004 c b e d e h l 16-pin sn ( 0.150" soic ) dimension inches millimeters min. max. min. max. a 0.060 0.070 1.52 1.78 a1 0.004 0.010 0.10 0.25 b 0.013 0.020 0.33 0.51 c 0.007 0.010 0.18 0.25 d 0.385 0.400 9.78 10.16 e 0.150 0.160 3.81 4.06 e 0.045 0.055 1.14 1.40 h 0.225 0.245 5.72 6.22 l 0.015 0.035 0.38 0.89 27 bq2092 ordering information bq2092 package option: sn = 16-pin narrow soic device: bq2092 gas gauge ic with smbus-like interface temperature range: blank = commercial (-20 to +70c) data sheet revision history change no. page no. description nature of change 1 21 correction in the self-discharge rate eeprom hex con - tents was: f0 is: df 1 21 correction in the self-discharge rate example values was: 0.15c is: 1.5% 2 3 updated application diagram 2 5 added vsb should not exceed 2.4v 2 12 clarified operation of bits 13 and 14 in batterymode() 2 13 clarified invalid data indication in runtimetoempty() 2 13 clarified invalid data indication in averagetimetoempty() 2 21 update formula for voltage divider in voltage gain. note: change 1 = nov. 1997 b changes from april 1997. change 2 = june 1999 c changes from nov. 1997 b. packaging information orderable device status (1) package type package drawing pins package qty eco plan (2) lead/ball finish msl peak temp (3) bq2092sn-a309 obsolete soic d 16 tbd call ti call ti bq2092sn-a309tr obsolete soic d 16 tbd call ti call ti bq2092sn-a311 active soic d 16 40 green (rohs & no sb/br) cu nipdau level-2-260c-1 year bq2092sn-a311g4 active soic d 16 40 green (rohs & no sb/br) cu nipdau level-2-260c-1 year bq2092sn-a311tr active soic d 16 2500 green (rohs & no sb/br) cu nipdau level-2-260c-1 year bq2092sn-a311trg4 active soic d 16 2500 green (rohs & no sb/br) cu nipdau level-2-260c-1 year (1) the marketing status values are defined as follows: active: product device recommended for new designs. lifebuy: ti has announced that the device will be discontinued, and a lifetime-buy period is in effect. nrnd: not recommended for new designs. device is in production to support existing customers, but ti does not recommend using this part in a new design. preview: device has been announced but is not in production. samples may or may not be available. obsolete: ti has discontinued the production of the device. (2) eco plan - the planned eco-friendly classification: pb-free (rohs), pb-free (rohs exempt), or green (rohs & no sb/br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. tbd: the pb-free/green conversion plan has not been defined. pb-free (rohs): ti's terms "lead-free" or "pb-free" mean semiconductor products that are compatible with the current rohs requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. where designed to be soldered at high temperatures, ti pb-free products are suitable for use in specified lead-free processes. pb-free (rohs exempt): this component has a rohs exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. the component is otherwise considered pb-free (rohs compatible) as defined above. green (rohs & no sb/br): ti defines "green" to mean pb-free (rohs compatible), and free of bromine (br) and antimony (sb) based flame retardants (br or sb do not exceed 0.1% by weight in homogeneous material) (3) msl, peak temp. -- the moisture sensitivity level rating according to the jedec industry standard classifications, and peak solder temperature. important information and disclaimer: the information provided on this page represents ti's knowledge and belief as of the date that it is provided. ti bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. efforts are underway to better integrate information from third parties. ti has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. ti and ti suppliers consider certain information to be proprietary, and thus cas numbers and other limited information may not be available for release. in no event shall ti's liability arising out of such information exceed the total purchase price of the ti part(s) at issue in this document sold by ti to customer on an annual basis. package option addendum www.ti.com 25-jun-2008 addendum-page 1 tape and reel information *all dimensions are nominal device package type package drawing pins spq reel diameter (mm) reel width w1 (mm) a0 (mm) b0 (mm) k0 (mm) p1 (mm) w (mm) pin1 quadrant bq2092sn-a311tr soic d 16 2500 330.0 16.4 6.5 10.3 2.1 8.0 16.0 q1 package materials information www.ti.com 11-mar-2008 pack materials-page 1 *all dimensions are nominal device package type package drawing pins spq length (mm) width (mm) height (mm) bq2092sn-a311tr soic d 16 2500 346.0 346.0 33.0 package materials information www.ti.com 11-mar-2008 pack materials-page 2 important notice texas instruments incorporated and its subsidiaries (ti) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. all products are sold subject to ti?s terms and conditions of sale supplied at the time of order acknowledgment. ti warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with ti?s standard warranty. testing and other quality control techniques are used to the extent ti deems necessary to support this warranty. except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. ti assumes no liability for applications assistance or customer product design. customers are responsible for their products and applications using ti components. to minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. ti does not warrant or represent that any license, either express or implied, is granted under any ti patent right, copyright, mask work right, or other ti intellectual property right relating to any combination, machine, or process in which ti products or services are used. information published by ti regarding third-party products or services does not constitute a license from ti to use such products or services or a warranty or endorsement thereof. use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from ti under the patents or other intellectual property of ti. reproduction of ti information in ti data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. reproduction of this information with alteration is an unfair and deceptive business practice. ti is not responsible or liable for such altered documentation. information of third parties may be subject to additional restrictions. resale of ti products or services with statements different from or beyond the parameters stated by ti for that product or service voids all express and any implied warranties for the associated ti product or service and is an unfair and deceptive business practice. ti is not responsible or liable for any such statements. ti products are not authorized for use in safety-critical applications (such as life support) where a failure of the ti product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of ti products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by ti. further, buyers must fully indemnify ti and its representatives against any damages arising out of the use of ti products in such safety-critical applications. ti products are neither designed nor intended for use in military/aerospace applications or environments unless the ti products are specifically designated by ti as military-grade or "enhanced plastic." only products designated by ti as military-grade meet military specifications. buyers acknowledge and agree that any such use of ti products which ti has not designated as military-grade is solely at the buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. ti products are neither designed nor intended for use in automotive applications or environments unless the specific ti products are designated by ti as compliant with iso/ts 16949 requirements. buyers acknowledge and agree that, if they use any non-designated products in automotive applications, ti will not be responsible for any failure to meet such requirements. following are urls where you can obtain information on other texas instruments products and application solutions: products applications amplifiers amplifier.ti.com audio www.ti.com/audio data converters dataconverter.ti.com automotive www.ti.com/automotive dsp dsp.ti.com broadband www.ti.com/broadband clocks and timers www.ti.com/clocks digital control www.ti.com/digitalcontrol interface interface.ti.com medical www.ti.com/medical logic logic.ti.com military www.ti.com/military power mgmt power.ti.com optical networking www.ti.com/opticalnetwork microcontrollers microcontroller.ti.com security www.ti.com/security rfid www.ti-rfid.com telephony www.ti.com/telephony rf/if and zigbee? solutions www.ti.com/lprf video & imaging www.ti.com/video wireless www.ti.com/wireless mailing address: texas instruments, post office box 655303, dallas, texas 75265 copyright ? 2008, texas instruments incorporated |
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