bqEASY™ Software
www.ti.com
the task list on the left and on the category tabs on top. A checkmark on a top tab only appears after all
tasks in the category have been completed. For example, in
all of the Setup tasks and all of the
Configure tasks have been completed. Completion marks are saved in the .EZY project text file. When a
completed or partially completed project file is opened, the user is given the chance to erase the
checkmarks.
10.6 Device Detection
The bqEASY™ program is designed to work with a fuel gauge present and already communicating with
the bqEVSW evaluation software through the EV2300 USB interface. When the evaluation software is
started, it reads the device type and displays it on the upper title block. This information is used by the
bqEASY™ program to select the correct default data-flash image (.DFI) and data-flash configuration file
(.ENCR) for this particular device. To ensure that the device has not changed, the bqEASY™ software
also checks the device type when the bqEASY button is pressed. If the correct files are not found, first
check the TI Web site in the EVM tool folder for the part being used, and download the latest version of
EV software with bqEASY™ support. If that fails to help, contact TI.
1. Setup
As the wizard questions and tasks are completed, completion checkmarks appear in two places –
along the task list on the left and on the category tabs on top. A checkmark on a top tab only appears
after all tasks in the category have been completed. Completion marks are saved in the .EZY project
text file. When a completed or partially completed project file is opened, the user is given the chance to
erase the checkmarks.
2. Configure
A series of eight screens is used to collect information about the battery pack application to enable
automatic configuration of the most critical data-flash parameters.
3. Calibrate
If you wish to proceed with either automatic chemistry selection or golden unit learning cycles, the
Impedance Track™ fuel gauge must be accurately calibrated. The bqEASY™ screens simply ask the
user to use the calibration screen of the bqEVSW for this purpose.
4. Chemistry
The chemistry choices presented in section 4B (
) are based on files in the \Chemistry folder
of the bqEASY™ application. The latest files are available for downloading from the ti.com Web site.
Automation of the chemistry-selection cycle is made possible using a simple load and switch as
depicted in
. The VOUT pin of the EV2300 may require a 1-M
Ω
pulldown resistor to ensure
that the switch is turned off when signaled to do so. The switch can be implemented with either a low
VGS-threshold FET or a small relay such as the OMICRON G6RN-1 with a 5-Vdc coil. Multiple
2N7000 FETs can be paralleled if nothing else is available. The load can be either a power resistor or
an electronic load set to a discharge rate of C/5. Hint: Follow the instructions exactly, or errors can
result.
5. Cycle
When preparing for mass production, cell learning is required, but only on one golden pack. The
chemical information learned from one pack is quickly transferred to all production units prior to
calibration. Doing this correctly requires a series of charge and discharge cycles. The discharge part
can be automated with the bqEASY™ program if the simple load circuit for the chemistry selection is
available. Follow the screen instructions.
18
bq27520EVM With System-Side, Single-Cell Impedance Track™ Technology
SLUU426 – June 2010
Copyright © 2010, Texas Instruments Incorporated
