Texas Instruments BQ76942EVM, Руководство пользователя

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BAT- is the reference voltage for the IC and should be connected first. After BAT- cells may be connected in any
order. Cell connection from the bottom up minimizes the voltage step size applied to the board. Recommended
connection sequence for the EVM when connecting cells is bottom up:
1. Connect BAT–
2. Connect cells bottom up; CELL1, CELL2, CELL3 ...
3. Be sure the cell simulator shunts are removed
Figure 4-5 shows an example connecting cells with an EVM configuration reduced to 9 cells.
Remove cell
simulator shunts
to avoid draining
cells
If connecting cells confirm operation before connecting.
Use all appropriate fusing, insulation, isolation and
shielding necessary for safe operation. Board has exposed
contacts. Do not leave unattended
For 9 cells, connect 8th
cell to both CELL8 and
CELL9 inputs
...
...
Figure 4-5. Example Connection with 9 Cells
4.7 Connecting to a Host
After initial operation of the monitor with the BQStudio software, it may be desirable to operate the board
connected to and controlled by a microcontroller board. J13 could be used to connect I2C signals to the
microcontroller board with GND and REG1 for a power supply from J2. The user should note that the J2 GND is
connected to the BQ76942 VSS and BAT- while the J13 reference is PACK-. With the connection shown in
Figure 4-6 the MCU runs from the battery voltage inside the protection FETs. If the MCU board provides pull ups
for the I2C lines, remove the PU shunts from J11 and J14. Alternately, the microcontroller board GND could be
referenced to the PACK- at J13. In this case the REG1 power supply would be modulated by the battery current.
Since the sense resistor is small, this is not normally a concern, but the user should be aware of the difference.
Do not connect the same reference to both the J2 GND and the J13 PACK- since this will short the sense
resistor through the external equipment and may lead to damage or unexpected results.
CAUTION
Do not connect the MCU board to both the J2 GND and J13 PACK- terminals, this will short the
sense resistor and could result in damage to equipment or unexpected results.
BQ76942 Circuit Module Use www.ti.com
20 BQ76942 Evaluation Module SLUUC32A – NOVEMBER 2019 – REVISED OCTOBER 2020
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