15-Cell Li-Ion Battery Controller Analog Front-End Reference Design

The TIDA00255 reference design utilizes the bq76940 analog front end (AFE) IC. It can measure battery voltage, mold temperature or external thermistor voltage using a 14-bit ADC. Current is measured individually by a separate 16-bit coulomb counter. The design turns off the low-side power FET to stop discharging or charging based on selected hardware limits. A microcontroller not included in this design will be part of the battery controller to communicate with the AFE to set protection thresholds, enable the power FETs, provide fault recovery, and shut down the FETs during over/under temperature conditions. Battery controller designs may include additional features that are not part of this reference design, such as secondary overvoltage protection, measurement, and isolated communications to inform the system of battery status.

characteristic

• ● Measure the battery voltage of 15 cells connected in series
• ● Use a 16-bit Coulomb counter to measure battery pack current
• ● Digital interface to microcontroller
• ● Hardware protection can be provided under discharge overcurrent, discharge short circuit, overvoltage and undervoltage conditions.