System-Side Fuel Gauge with Dynamic Voltage Correlation, Battery Gas Gauge - BQ27621-G1

BQ27621-G1 (ACTIVE)

System-Side Fuel Gauge with Dynamic Voltage Correlation, Battery Gas Gauge



The Texas Instruments bq27621-G1 is a minimally configured microcontroller peripheral that provides system-side fuel gauging for single-cell Li-Ion batteries. The device requires very little user configuration and system microcontroller firmware development.

The bq27621-G1 uses the Dynamic Voltage Correlation algorithm for fuel gauging. This process eliminates the need for a sense resistor when calculating remaining battery capacity (mAh), state-of-charge (%), battery voltage (mV), and temperature (°C).

Battery fuel gauging with the bq27621-G1 requires connections only to PACK+ (P+) and PACK– (P–) for a removable battery pack or embedded battery circuit. The tiny 9-pin, 1.62 mm × 1.58 mm, 0.5 mm pitch YZF package is ideal for space-constrained applications.


  • Single-Cell Li-Ion Battery Fuel Gauge
    • Resides on System Board
    • Supports Embedded or Removable Batteries
    • Powered Directly from Battery with Integrated
  • Easy To Configure Fuel Gauging Based on the
    Dynamic Voltage Correlation Algorithm
    • Reports Remaining Capacity and State of
      Charge (SOC) with Smoothing Filter
    • Automatically Adjusts for Self-Discharge,
      Temperature, and Rate Changes
  • Microcontroller Peripheral Supports:
    • 400-kHz I2C Serial Interface
    • Configurable SOC Interrupt or
      Battery Low Digital Output Warning
    • Internal Temperature Sensor or
      Host Reported Temperature
  • Support 4.2-V, 4.3-V, and 4.35-V Chemistries
  • 9-pin 1.62 × 1.58 mm, 0.5 mm pitch YZF package

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Parametrics Compare all products in Battery Fuel Gauge

Number of Series Cells
Cell Chemistry
Battery Capacity (Max) (mAh)
Communication Interface
Battery Capacity (Min) (mAh)
External Capacity Indication
Gas Gauge Algorithm
Cell Balancing
Operating Temperature Range (C)
BQ27621-G1 BQ27220 BQ27426 BQ27520-G4 BQ27542-G1 BQ35100
Single Cell    Single Cell    Single Cell    Single Cell    Single Cell    2-4 Cells
>4 Cells
Single Cell   
Li-Ion/Li-Polymer    Li-Ion/Li-Polymer    Li-Ion/Li-Polymer    Li-Ion/Li-Polymer    Li-Ion/Li-Polymer    Primary Lithium   
6000    29000    14000    32000    14600    32000   
I2C    I2C    I2C    I2C    HDQ
100    100    100    300    100    100   
None    None    None    None    None    None   
System    Pack
System    System    Pack    Pack
Dynamic Voltage Correlation    CEDV    IT (High accuracy)    IT (High accuracy)    IT (High accuracy)    Primary   
N/A    N/A    N/A    N/A    N/A    N/A   
No Sense Resistor Required    N/A    N/A    N/A    SHA-1 Authentication
Turbo Mode   
-40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85    -40 to 85   
9DSBGA    9DSBGA    9DSBGA    15DSBGA    12SON    14TSSOP