2 General Description
TI's BQ79631EVM is an evaluation board for the BQ7963X-Q1 family of devices for use in EV/HEV applications
to provide monitoring, protecting, and communications by measuring divided down high voltage in the battery
junction box (BJB) or battery disconnect unit (BDU) system.
The BQ79631EVM is equipped with 16 differential voltage sense inputs in order to measure across the battery
pack, fuse, drive train link, and fast charging connections. The two voltage sense pins (VC14, VC15) connected
to HV_Extra1_Plus and HV_Extra2_Plus may be used to measure other parameters within the HV system. An
insulation detection circuit is also present on the BQ79631EVM to ensure that all high voltage networks are
properly insulated from low voltage ones. All differential voltage sense inputs are integrated post ADC in digital
low pass filters.
In addition to the voltage sense pins, the BQ79631EVM also has integrated current sense with a low shunt
resistor. There are also 8 GPIOs/auxiliary inputs that can be used to measure additional voltages, NTC
thermistors, and drive relays.
Bi-directional daisy chain ports are also present on the BQ79631EVM and support capacitor, capacitor and
choke, and transformer based isolation.
Control a single EVM or multiple stacked EVMs using a PC-hosted GUI. Communication between the PC and
the bridge device occurs via a USB2ANY UART interface. When using the BQ7963x in a system of other
stacked BQ796XXEVM devices, communication between all other EVMs in the stack occurs via the isolated,
daisy-chain differential communication bus.
The PC GUI allows configuration all BQ796XXEVMs to monitor cells and other analog data channels, control
balancing, and monitor details of any faults. For more information on the installation and use of the BQAutoEval
GUI, please refer to the
BQ79616-Q1 and BQ75614-Q1 GUI User's Guide
.
For more information on specific details pertaining to the BQ79616EVM, please refer to the
BQ75614-Q1, and BQ79656-Q1 Evaluation Modules User's Guide
2.1 Key Features
This EVM includes the following features:
• Differential voltage measurements with integrated filtering
1. Link ± voltage measurement for connection to drive train
2. HV_Fuse voltage measurement to monitor a fuse that connects the battery pack to the rest of the BJB
3. HV ± voltage measurement for connection to battery pack
4. Charge ± voltage measurement for connection to charging port
5. Two additional HV voltage measurements to monitor any other location in the HV system
• Insulation detection
• Isolated differential daisy chain communications with optional ring architecture
• 8 NTC/Auxiliary/GPIO channels
• UART interface
• Diagnostics
• Integrated current measurement
• Built-in host controlled hardware reset to emulate POR-like device reset
2.1.1 Key Electrical Parameters
The following table identifies the key electrical parameters:
Table 2-1. Key Electrical Parameters
Parameter
Value
Maximum battery pack voltage (stacked EVMs)
2400 V
Maximum operating voltage
80 V (depends on series R3, R4 value)
Minimum operating voltage
9 V (depends on series R3, R4 value, by default use at least 18V)
Maximum cell open circuit voltage
5 V
General Description
6
BQ79631EVM Evaluation Module
SLUUCC3 – FEBRUARY 2021
Copyright © 2021 Texas Instruments Incorporated
