SLUUBD4A April 2016 – November 2022 BQ27220
To use gm.fs files to configure the BQ27220 device on power up, do the following:
Step 1: Use the GPCCEDV tool (on ti.com) to generate the 7-point CEDV parameter and the 11-point loaded voltage points. Refer to the BQ27220EVM-744 User's Guide (SLUUBF5).
Step 2: Use the Battery Management Studio (BQStudio) software (the fuel gauge evaluation software) to finalize all the values for Calibration/Configuration/Gas Gauging in RAM based on the application.
Step 3: Use BQStudio to generate a gm.fs file, which contains I2C instructions (with data) to write all the parameters (from Step 2) by the host on power up.
Step 4: Use the gm.fs to program the BQ27220 RAM every time on a power up.
The host programs the configuration/profile into one of the three available OTP areas.
The BQ27220 fuel gauge has two One-Time Programmable (OTP) areas for custom CEDV profile programming. In cases where the user does not want to program the RAM in the BQ27220 device every time on a power up, there is a provision to program the custom CEDV profiles in the OTP area of the BQ27220 device. Once programmed, the fuel gauge automatically uses the OTP profile the next time the gauge is powered up.
The BQ27220 device has two sections of the OTP that are available for the user: