bq2168 Li-Ion Power Gauge™ Module with Pack Supervisor Features ➤ Complete and compact lithium ion gas gauge and protection solution for three or four series cells ➤ Accurate measurement of available battery capacity ➤ Provides overvoltage, undervoltage, and overcurrent protection ➤ Designed for battery pack integration – Small size – Includes bq2050H and bq2058 ICs – On-board charge and discharge control FETs – Low operating current for minimal battery drain ➤ High side FET control ➤ Battery capacity available through single-wire serial port ➤ or graphite anode), and the threshold limits. Figure 1 shows how the module connects to the cells. The bq2168L includes five LEDs to display remaining capacity in 20% increments of the learned capacity. The LEDs are activated with the onboard push-button switch. “L” version includes 5 push-button activated LEDs to display state-of-charge information A module development kit is also available for the bq2168. The bq2168B-KT or the bq2168LB-KT includes one configured module and the following: General Description The bq2168 Power Gauge Module provides a complete and compact battery management solution for Li-Ion battery packs. Designed for battery pack integration, the bq2168 combines the bq2050H Power Gauge IC with the bq2058 Supervisor IC on a small printed circuit board. The board includes all the necessary components to accurately monitor battery capacity and protect the cells from overvoltage, undervoltage, and overcurrent conditions. The board works with three or four Li-Ion series cells. 1) An EV2200-50H interface board that allows connection to the serial port of any AT-compatible computer. 2) Menu driven software to display charge/discharge activity and to allow user interface to the bq2050H from any standard Windows 3.1x or 95 PC. Pin Descriptions The Power Gauge IC uses the on-board sense resistor to track charge and discharge activity of the battery pack. Critical battery information can be accessed through the serial communications port at HDQ. The supervisor circuit consists of the bq2058 and two FETs. The bq2058 controls the FETs to protect the batteries during charge/discharge cycles and short circuit conditions. The bq2168 provides contacts for the positive and negative terminals of each battery in the stack. Please refer to the bq2050H and bq2058 data sheets for the specifics on the operation of the power gauge and supervisor ICs. Unitrode configures the bq2168 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, the Li-Ion battery type (coke 5/99 B 1 POS Pack positive B1P BAT1P/Battery 1 positive input B1N BAT1N/Battery 1 negative input B2N BAT2N/Battery 2 negative input B3N BAT3N/Battery 3 negative input B4N BAT4N/Battery 4 negative input ITEST Overcurrent test input HDQ Serial communications port NEG Pack negative bq2168 Battery Pack Cells B4N B3N B2N B1N B1P bq2168 NEG POS PACK- PACK+ Load Charger FG2168-1.eps Figure 1. Module Connection Diagram Table 1. bq2168 Module Configuration Customer Name: ___________________________________________________________________________ Contact: _________________________________________ Phone: ______________________________ Address: _________________________________________________________________________________ _________________________________________________________________________________ Sales Contact: ____________________________________ Phone: ______________________________ Number of series cells (3 or 4) _____________ Coke or graphite cell anode _____________ Battery pack capacity (mAh) _____________ Discharge current into load (3.9A max.) min. ________ avg. _________ max. _________ Charge current (3.9A max) _____________ Self-discharge compensation (Y/N) _____________ Overvoltage threshold (4.25, 4.30, or 4.35V) _____________ LEDs and switch (Y/N) _____________ FAE approval: ____________________________________ 2 Date: _______________________________ bq2168 B1P NC B1P POS B1N B1N Load or Charger B2N Load or Charger B2N B3N B3N B4N POS B4N NEG NEG Four-Cell Configuration Three-Cell Configuration Note: B1P, B4N, POS, and NEG accomodate a #20 AWG stranded wire. B1N, B2N, and B3N accomodate a #24 AWG stranded wire. FG2158cc.eps Figure 1. Module Connection Diagram 3 bq2168 bq2168 Schematic 1 2 3 4 Component values depend on user-provided information in Table 1. 2168La.eps 4 bq2168 bq2168 Schematic (Continued) 2168Lb 5 bq2168 bq2168 Board 6 bq2168 Absolute Maximum Ratings Symbol Parameter Value Unit Conditions VOP Supply voltage (B1P to B4N) 18 V DC VTR Maximum transient voltage (B1P to B4N) 32 V Maximum duration = 1.5µs VCHG Charging voltage (POS to NEG) 18 V ICHG Continuous charge/discharge current 3.9 A TOPR Operating temperature 0 to +70 °C TSTG Storage temperature -55 to +125 °C Note: VOP > 6V TA = 25°C 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 4.0 - 18 V VOP Operating voltage, B1P to B4N ICCA Operating current - - 350 µA RON On resistance, B1P to POS - - 50 mΩ 7 Conditions/Notes TA = 25°C VOP = 10V bq2168 DC Thresholds (TA = TOPR) Symbol Parameter Value Tolerance Unit VOV Overvoltage threshold 4.25 ± 50mV V VCE Charge enable voltage VOV - 100mV ± 50mV V VUV Undervoltage limit 2.25 ± 100mV V IOC Overcurrent limit tUVD Undervoltage delay Notes 3.4 A TA = 25°C 3.8 A TA = 60°C TA = 30°C 950 ±50% ms VCD Charge detect threshold 70 -60, +80 mV tOVD Overvoltage delay 950 ±50% ms TA = 30°C tOCD Overcurrent delay 12 ±60% ms TA = 30°C Note: The thresholds above reflect the operation of a bq2158 using the standard bq2058 IC (VOV = 4.25V). Specify other versions of the bq2058 by indicating the appropriate VOV threshold in Table 1. Data Sheet Revision History Change No. Page No. 1 All Note: Description From Preliminary to Final Change 1 = May 1999 B changes from Apr. 1999. Ordering Information bq2168 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: Li-Ion Power Gauge Module with Pack Supervisor Notes: 1. Requires configuration sheet (Table 1) 2. Example production part number: bq2168LB-001 8 Nature of Change 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. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI’s publication of information regarding any third party’s products or services does not constitute TI’s approval, warranty or endorsement thereof. Copyright 1999, Texas Instruments Incorporated