Product details


Cell chemistry Lead Acid, Li-Ion/Li-Polymer, NiCd, NiMH Number of series cells Single Cell Communication interface HDQ Implementation Pack Operating temperature range (C) -20 to 70 open-in-new Find other Battery fuel gauges

Package | Pins | Size

SOIC (D) 8 19 mm² 3.91 x 4.9 TSSOP (PW) 8 19 mm² 3 x 6.4 open-in-new Find other Battery fuel gauges


  • Multifunction charge/discharge counter
  • Resolves signals less than 12.5uV
  • Internal offset calibration improves accuracy
  • 1024 bits of NVRAM configured as 128 x 8
  • Internal temperature sensor for self-discharge estimation
  • Single-wire serial interface
  • Dual operating modes:
    - Operating: <80uA
    - Sleep: <10uA
  • REG output for low-cost microregulation
  • Internal timebase eliminates external components
  • 8-pin TSSOP or SOIC allows battery pack integration
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The bq2018 is a low-cost charge/discharge counter peripheral packaged in an 8-pin TSSOP or SOIC. It works with an intelligent host controller, providing state-of-charge information for rechargeable batteries.

The bq2018 measures the voltage drop across a low-value series sense resistor between the negative terminal of the battery and the battery pack ground contact. By using the accumulated counts in the charge, discharge, and self-discharge registers, an intelligent host controller can determine battery state-of-charge information. To improve accuracy, an offset count register is available. The system host controller is responsible for the register maintenance by resetting the charge in/out and self-discharge registers as needed.

The bq2018 also features 128 bytes of NVRAM registers. The upper 13 bytes of NVRAM contain the capacity monitoring and status information. The RBI input operates from an external power storage source such as a capacitor or a series cell in the battery pack, providing register nonvolatility for periods when the battery is shorted to ground or when the battery charge state is not sufficient to operate the bq2018. During this mode, the register backup current is less than 100nA.

Packaged in an 8-pin TSSOP or SOIC, the bq2018 is small enough to fit in the crevice between two A-size cells or within the width of a prismatic cell.

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Technical documentation

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Type Title Date
* Data sheet Power Minder IC datasheet Sep. 05, 1999
Application note Gas Gauging Basics Using TI Battery Monitor ICs (Rev. A) Oct. 17, 2003
Application note Advanced Gas Gauge Firmware Flowchart for TI Battery Monitor ICs Aug. 28, 2002
Application note Advanced Gas Gauge Host Firmware for TI Battery Monitor ICs May 16, 2001
Application note HDQ Communication Basics for TI Battery Monitor ICs May 16, 2001
User guide bq2018 EVM Apr. 10, 2000
User guide bq2018 Power Minder Demonstration Module Apr. 10, 2000
User guide DM2382 Gas Gauge Peripheral and Li-Ion Pack Protection Demo Board Sep. 05, 1999
Application note Designed to Go: Universal Battery Monitor Using the bq2018 Power Minder IC Sep. 05, 1999
User guide EV2200-18 Evaluation System User Guide Sep. 05, 1999

Design & development

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CAD/CAE symbols

Package Pins Download
SOIC (D) 8 View options
TSSOP (PW) 8 View options

Ordering & quality

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