bq2114 Features NiCd or NiMH Gas Gauge Module with Charge-Control Output ä Complete bq2014 Gas Gauge solution for NiCd or NiMH battery packs ä Charge-control output allows communication to external charge controller (bq2004) ä Battery information available over a single-wire bidirectional serial port ä Battery state-of-charge monitoring for 4- to 12-cell series applications ä On-board regulator allows direct connection to the battery ä “L” version includes push-button activated LEDs to display state-of-charge information ä Nominal capacity and cell chemistry pre-configured ä Compact size for battery pack integration A module development kit is also available for the bq2114. The bq2114B-KT or bq2114LB-KT includes one configured module and the following: General Description 1) An interface board that allows connection to the serial port of an AT-compatible computer. The bq2114 Gas Gauge Module provides a complete and compact solution for capacity monitoring of NiCd and NiMH battery packs. Designed for battery pack integration, the bq2114 incorporates a bq2014 Gas Gauge IC, a current sense resistor, and all other components necessary to accurately monitor and display the capacity of 4 to 12 series cells. The bq2114L includes five surfacemounted LEDs to display remaining capacity in 20% increments of the learned capacity (relative mode). The LEDs are activated with the onboard push-button switch. 2) Menu-driven software with the bq2114 to display charge/discharge activity and to allow user interface to the bq2014 from any standard DOS PC. 3) Source code for the TSR. Pin Descriptions P1 DQ/Serial communication port P2 BAT+/Battery positive/pack positive Contacts are provided on the bq2114 for direct connection to the battery stack (BAT+, BAT-), the serial communications port (DQ), the empty indicator (EMPTY), and the charge control output (CHG). Please refer to the bq2014 data sheet for the specifics on the operation of the Gas Gauge. P3 CHG/Charge control output P4 EMPTY/Empty indicator output P5 GND/Ground P6 PACK-/Pack negative Unitrode configures the bq2114 based on the information requested in Table 1. The configuration defines the number of series cells, the nominal battery pack capacity, and the self-discharge rate. P7 BAT-/Battery negative 5/99 B 1 bq2114 Battery Pack Cells P7 bq2114 P2 P6 PACK- PACK+ Load Charger FG211401.eps Figure 1. Module Connection Diagram Table 1. bq2114 Module Configuration Customer Name: ___________________________________________________________________________ Contact: _________________________________________ Phone: ______________________________ Address: _________________________________________________________________________________ _________________________________________________________________________________ Sales Contact: ____________________________________ Phone: ______________________________ Number of series battery cells (4–12) ________________________________________ Battery type (NiCd or NiMH) ________________________________________ Battery pack capacity (mAh) ________________________________________ Discharge rate into load (3.0A max.) Min. Charge rate (3.0A max.) ________________________________________ LEDs and switch (Y/N) ________________________________________ Avg. FAE approval: _____________________________________ 2 Max. Date:________________________________ bq2114 bq2114 Schematic Note: Schematic shows components which may not be placed on the board, depending upon the configuration. 3 bq2114 bq2114 Board 4 bq2114 Absolute Maximum Ratings Symbol Parameter Minimum Maximum Unit Conditions VCC Relative to VSS -0.3 +7.0 V bq2014 All other pins Relative to VSS -0.3 +7.0 V bq2014 PSR Continuous sense resistor power dissipation - 3 W Thru-hole sense resistor - 1 W Surface-mount sense resistor ICHG Continuous charge/ discharge current - 3.0 A TOPR Operating temperature 0 +70 °C TSTR Storage Temperature -40 +85 °C Note: Commercial Permanent device damage may occur if Absolute Maximum Ratings are exceeded. Functional operation should be limited to the Recommended DC Operating Conditions detailed in this data sheet. Exposure to conditions beyond the operational limits for extended periods of time may affect device reliability. DC Electrical Characteristics (TA = TOPR) Symbol Parameter Minimum Typical Maximum Unit Conditions/Notes NumCell Number of series cells in battery pack 4 - 12 - BAT+ Positive terminal of pack GND NumCell ∗ 1.2V NumCell ∗ 1.8V V BAT- Negative terminal of pack GND - 0.3 - GND+2.0 V ICC Supply current at BAT+ terminal (no external loads) - 200 300 µA RDQ Internal pull-down 500k - - Ω1 IOL Open-drain sink current DQ, EMPTY, CHG - - 5.0 mA1 VOL Open-drain output low, DQ, EMPTY, CHG - - 0.5 V1 VIHDQ DQ input high 2.5 - - V1 VILDQ DQ input low - - 0.8 V1 VOS Voltage offset - - 150 µV1 Note: 1. Characterized on PCB, IC 100% tested. 5 IOL < 5mA bq2114 DC Voltage Thresholds (TA = TOPR) Symbol Parameter Minimum Typical Maximum Unit 0.93 0.95 0.97 V Notes BAT+/NumCell1 VEDVF Final empty warning VEDV1 First empty warning 1.03 1.05 1.07 V BAT+/NumCell1 VMCV Maximum single-cell voltage 2.20 2.25 2.30 V BAT+/NumCell1 VSRO Sense resistor range -300 - +2000 mV VSR + VOS2 VSRQ Valid charge 375 - - µV VSR + VOS 2, 3 VSRD Valid discharge - - -300 µV VSR + VOS 2, 3 Notes: 1. At SB input of bq2014. 2. At SR input of bq2014. 3. Default value; value set in DMF register. Data Sheet Revision History Change No. Page No. 1 2 Updated Table 1 to include 3.0A limit 1 5 Added 3.0A maximum continuous charge/discharge current specification Note: Description Change 1 = May 1999 B changes from Sept. 1996. Ordering Information bq2114 B– Customer Code: Blank = Sample or Pre-production1 KT = Evaluation system XXX = Customer-specific; assigned by Unitrode2 Package Option: B = Board-level product LED Option: L = LEDs plus switch Blank = No LEDs or switch Device: NiCd or NiMH Gas Gauge Module with Charge-Control Output Notes: 1. Requires configuration sheet (see Table 1) 2. Example production part number: bq2114LB-003 6 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. 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