Theory of Operation
7
SLOU471E – May 2017 – Revised April 2019
Copyright © 2017–2019, Texas Instruments Incorporated
BQ79606A-Q1 Evaluation Module
The typical flow is for the host to go through the following simplified sequence:
1. Wakeup the BQ79606EVM board by sending a WAKEUP pulse when using the UART interface, or
sending a WAKE tone when using the BQ79606EVM in a stack of other BQ79606EVM boards for a
large battery pack or a BQ79606-Q1 configured as a bridge. Initialize the BQ79606A-Q1 to be ready
for use.
2. Send a sample command to the BQ79606A-Q1 to read the cell measurement results.
3. The host will use the cell measurement data to calculate an average and determine the highest or
lowest cells and determine the cells that should be balanced.
4. If no stop command is sent, the BQ79606A-Q1 has a built-in timeout (set by the user), after which time
the discharge will be stopped automatically.
5. The host can then decide to repeat the process (back to step 2) or send commands to shutdown the
BQ79606EVM and return later.
2.1
Single Board
As a single board the BMS can passively balance up to 6 cells, up to 30 V of total voltage. Communication
to the BQ79606EVM is handled by the daisy-chain communications bus from another BQ79606A-Q1 or
the UART host interface.
2.2
Stacked Systems
The BMS boards may be stacked up to 1300 V. Communication to the BQ79606EVM is handled by the
daisy-chain communications bus from another BQ79606A-Q1.
3
Connectors
3.1
Primary Input and Output Connectors
3.1.1
Battery Connector
The battery cell connections are made from connector J1. Cell voltage measurements and balancing
currents use these connections. Short unused channels to the top cell connection in the wiring harness to
support fewer than 6 cells.
Figure 2. Molex 39502-1009 (Reference Image Only)
Table 1. Connector Information
Designator
Manufacturer
Part Number
Mating Connector
J1
Molex
Manufacturer: 39502-1009
Digi-Key: WM7777-ND
Manufacturer: 39500-0009
Digi-Key: WM7739-ND