 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
BQ2092 Datasheet(PDF) 5 Page - Texas Instruments |
|
||||||||||||||||||||||||||||||
BQ2092 Datasheet(HTML) 5 Page - Texas Instruments |
|
|
5 / 30 page  Voltage Thresholds In conjunction with monitoring VSR 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, R5 is connected to the positive battery terminal, and R4 is connected to the negative battery terminal. R5/R4 should be rounded to the next highest integer. The voltage at the SB pin (VSB) 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 VSB is below either of the two EDV thresholds, the associ- ated flag is latched and remains latched, independent of VSB, 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 VSS pins. VOS (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: n The capacitors (C1, C2, and C4) should be placed as close as possible to the SB and VCC pins, and their paths to VSS should be as short as possible. A high-quality ceramic capacitor of 0.1 µf is recommended for VCC. n The sense resistor capacitor (C3) should be placed as close as possible to the SR pin. n The sense resistor (R1) should be as close as possible to the bq2092. n The IC should be close to the cells for the best temperature measurement. n An optional zener may be necessary to ensure VCC 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 VCC 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 Obsolete Device |
Similar Part No. - BQ2092_15 |
|
Similar Description - BQ2092_15 |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
