bq2112 NiCd or NiMH Gas Gauge Module with Slow-Charge Control Features ä Complete bq2012 Gas Gauge solution for NiCd or NiMH battery packs ä Output for slow-charge control of battery pack 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 bq2112. The bq2112B-KT or bq2112LB-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 bq2112 Gas Gauge Module provides a complete and compact solution for capacity monitoring of NiCd and NiMH battery packs. Designed for battery pack integration, the bq2112 incorporates a bq2012 Gas Gauge IC, a current sense resistor, and all other components necessary to accurately monitor and display the capacity of 3 to 12 series cells. The bq2112L includes six surfacemounted LEDs to display remaining capacity in 20% increments of the learned capacity (relative mode) or programmed capacity (absolute mode). The sixth LED is used in absolute mode to represent an overfull condition (charge above the programmed capacity). The LEDs are activated with the onboard push--button switch. 2) Menu-driven software with the bq2112 to display charge/discharge activity and to allow user interface to the bq2012 from any standard DOS PC. 3) Source code for the TSR. Contacts are provided on the bq2112 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 bq2012 data sheet for the specifics on the operation of the Gas Gauge. Pin Descriptions Unitrode configures the bq2112 based on the information requested in Table 1. The configuration defines the number of series cells, the nominal battery pack capacity, the self-discharge rate, and the LED display mode. 5/99 B 1 P1 DQ/Serial communication port P2 BAT+/Battery positive/pack positive P3 CHG/Charge control output P4 EMPTY/Empty indicator output P5 GND/Ground P6 PACK-/Pack negative P7 BAT-/Battery negative bq2112 Battery Pack Cells P7 bq2112 P6 P2 PACK+ PACKLoad Charger FG-961 Figure 1. Module Connection Diagram Table 1. bq2112 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) ________________________________________ Display mode (absolute or relative) ________________________________________ LEDs and switch (Y/N) ________________________________________ Avg. FAE approval: _____________________________________ 2 Max. Date:________________________________ bq2112 bq2112 Schematic Note: Schematic shows components which may not be placed on the board, depending upon the configuration. 3 bq2112 bq2112 Board 4 bq2112 Absolute Maximum Ratings Symbol Parameter Minimum Maximum Unit Conditions VCC Relative to VSS -0.3 +7.0 V bq2012 All other pins Relative to VSS -0.3 +7.0 V bq2012 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 NumCell Number of series cells in battery pack 4 - 12 - BAT+ Positive terminal of pack GND 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: NumCell * 1.2V NumCell * 1.8V 1. Characterized on PCB, IC 100% tested. 5 Conditions/Notes V IOL < 5mA bq2112 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 bq2012. 2. At SR input of bq2012. 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 Nov. 1997. Ordering Information bq2112 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 Slow-Charge Control Notes: 1. Requires configuration sheet (see Table 1) 2. Example production part number: bq2112LB-002 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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