Texas Instruments Evaluation Module for BQ76925 Analog Front End for 3 to 6 Series Lithium-Ion Cells BQ76925EVM BQ76925EVM Datenbogen
Produktcode
BQ76925EVM
3-, 4-, and 5-Cell Operation
Table 20. Example of a Device Connect Command (continued)
I2C_W:
21
12
0F
I2C_R:
40
0
0
2
30
3
32
2
15
2
15
3
FF
2
2D
I2C_W:
21
11
6
I2C_R:
40
0
0
2
30
3
35
2
21
2
21
3
FF
2
2F
I2C_W:
21
10
1
I2C_R:
40
0
0
2
30
3
2F
2
2C
2
2C
3
FF
2
2E
I2C_W:
23
0
25
I2C_R:
40
0
0
2
2F
3
2F
2
36
2
34
3
FE
2
30
I2C_W:
25
0
D9
I2C_R:
25
0
CC
I2C_W:
21
10
1
I2C_R:
40
0
0
2
30
3
2F
2
2C
2
2C
3
FF
2
2E
I2C_W:
23
0
25
I2C_R:
40
0
0
2
2F
3
2F
2
36
2
34
3
FE
2
30
I2C_W:
25
0
D9
I2C_R:
25
0
CC
In general, polling data involves writing to the Control Registers of the bq76925 to configure the outputs
(VCOUT, VIOUT and VTB) and then reading the results from the MSP430.
(VCOUT, VIOUT and VTB) and then reading the results from the MSP430.
6
3-, 4-, and 5-Cell Operation
This section includes instructions for setting up the bq76925EVM for operation with less than 6 cells. The
discussion considers operation with the cell simulator only.
discussion considers operation with the cell simulator only.
6.1
Introduction
The bq76925 is capable of working with cell packs that have 3-, 4-, 5-, or 6-series connected cells. There
are some special considerations when operating with less than six series cells. For complete information,
consult the bq76925 data sheet.
are some special considerations when operating with less than six series cells. For complete information,
consult the bq76925 data sheet.
CAUTION
Configure the bq76925EVM for the appropriate cell count prior to applying
power to the board.
power to the board.
6.2
Using Onboard Cell Simulator
The cell simulator can be set up for 3-, 4-, 5-, or 6-cell operation. The process simply involves placing a
shorting wire across the proper pins on the CN6:CELLS connector.
shorting wire across the proper pins on the CN6:CELLS connector.
6.3
Five-Cell Operation
The procedure for five-cell operation with the simulation circuit is as follows:
1. Ensure that the power to the board, at BATT+/-, is removed.
2. Close all switches on S4.
3. Apply a jumper wire from pin 1 to pin 2 on connector CN6. These are the inputs marked Cell 6 and
2. Close all switches on S4.
3. Apply a jumper wire from pin 1 to pin 2 on connector CN6. These are the inputs marked Cell 6 and
Cell 5.
4. Set the power supply to a safe level for 5-cell operation. This is somewhere below 25 V.
5. Connect the power supply to BATT+ and BATT
5. Connect the power supply to BATT+ and BATT
–
.
6. Turn on the power supply.
7. Connect to the evaluation software.
7. Connect to the evaluation software.
31
SLUU514
–
July 2011
bq76925EVM Evaluation Module
Copyright
©
2011, Texas Instruments Incorporated