3 Theory of Operation - Standalone BQ75614EVM
shows the system block diagram.
Figure 3-1. System Block Diagram - BQ75614
The BMS system is designed to prolong the useful life of lithium-ion cells in battery packs through passive
balancing, and provide enhanced SOC and SOH measurements using integrated current sense measurement.
The device can monitor a battery pack which contains up to 16 cells, or up to 14 cells with the ability to measure
fuse and relay voltages. This system will monitor voltages of individual battery cells and dissapate individual cell
voltages through the use of internal CB FETs. The BMS allows battery-powered electric machines to use smaller
battery packs and use fewer charging cycles to perform the same amount of work. It also improves the overall
lifetime of Li-ion battery packs by preventing under- and overvoltage damage from occurring.
The typical BMS system with integrated current sense has two main sub-systems, as shown in
• Host controller - in this case a TMS570 LaunchPad
™
• BQ75614EVM module attached to cells, and communicating with the host
• Optional: a digital isolator between the host domain and the BQ75614EVM domain
All commands and data are communicated with a host via UART. The BQ75614-Q1 will remain idle until a
command is received from the host. The BQ75614EVM can support a host PC or microcontroller (via the UART
connection header).
Theory of Operation - Standalone BQ75614EVM
SLUUC37B – JULY 2019 – REVISED OCTOBER 2020
BQ79616-Q1, BQ75614-Q1, and BQ79656-Q1 Evaluation Modules
9
Copyright © 2020 Texas Instruments Incorporated
