ISL9208EVAL2Z Intersil, ISL9208EVAL2Z Datasheet - Page 4

• Manufacturer Part Number: ISL9208EVAL2Z
• Description: EVAL BOARD 2 FOR ISL9208
• Manufacturer: Intersil

Specifications of ISL9208EVAL2Z

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

USB to I
• Once the power supply connections are verified,
• Connect the I
.
• CAUTION: The I
Testing the Board
• Power-up the board and start the GUI. Now, the PC will be
• The GUI should power up with some color. In this case,
• If the FET indicators remain RED after power up, then it is
The microcontroller on the board performs a number of
automatic functions. These are:
1. The cell inputs are monitored for too high or too low
2. After an overcurrent or undervoltage condition, the
power-down the ISL9208EVAL2Z boards and make the
PC connection to the board, via the USB port, the
DeVaSys board, and the I
connection, make sure that the USB to I
software is installed (see software installation guide).
ISL9208EVAL2Z as in Figure 5. Use the 5-pin to 4-pin
cable provided in the ISLI2C-KIT.
Battery negative terminal. If a load connected between the
Pack + and Pack - pins has the same ground reference as
the PC, then both sides of the power FETs will be
connected together through the PC and load ground
leads, so there will be no interruption in the power path.
Also, without proper care, there can be problems with
ground loops or excess voltage conditions as a result of
this connection. If this may be a concern, see “I
Isolation” on page 7.
communicating with the microcontroller and the
microcontroller will be communicating with the ISL9208.
the FET controls should be GREEN and the indicators
should be all be green. If the GUI is all gray, then there is a
communication problem. If there is a communication
problem, see the troubleshooting guide in the Appendix.
likely that at least one input voltage or the temperature is
out of range.
voltage. If any of the cell voltages go too high, the charge
FET is turned off. If any of the cell voltages go too low, the
discharge FET turns off. When the voltage recovers from
these excursions, back into the normal range, the FETs
automatically turn on.
microcontroller monitors the load and turns the FETs
back on when the load is released.
FIGURE 5. I
ISL9208EVAL2Z
FETs
2
C interface
GND
SDA
2
SCL
C cable from the interface board to the
NC
2
2
C interface ground pin connects with the
J8
C CONNECTION TO ISL9208 PCB
SUPPLIED WITH ISLI2C-KIT
J29
1
4-PIN CONNECTOR
5-PIN TO 5-PIN
USE 5-PIN TO
2
C cable. Before making this
CABLE
4
DeVaSys BOARD
2
C interface
1
USB
Application Note 1444
2
C
J2
Over/Undervoltage Testing
• Test the overvoltage and undervoltage conditions by:
Overcurrent Testing
Testing the overcurrent settings with the ISL9208EVAL2Z
Rev A is not easy without changing the values of the sense
resistors on the board, because it was designed as a
possible reference application.
As delivered, the ISL9208EVAL2Z provides a discharge
sense resistor of 2.5mΩ and a charge sense resistor of
50mΩ. To get a discharge short circuit condition requires
80A. To get a discharge overcurrent condition requires a
load of 40A. To get a charge overcurrent condition requires
2A. Changing both resistors to 0.5Ω provides a mechanism
for easily testing the current thresholds.
To test the board in an application most likely requires that
battery cells be used and that there is a large load available.
While the board was not extensively tested for these high
load currents, the traces are short and wide enough to
(theoretically) handle the currents up to the 40A threshold.
Cell Balance Testing
• Testing the cell balance operation requires the use of
• Start the cell balance test by first observing if the cell with
3. The microcontroller monitors the temperature and turns
4. The microcontroller performs cell balancing (once it is
5. The microcontroller monitors the cell voltages and reports
Li-ion cells or a power supply, or requires modifying the
board to use 1000Ω cell balancing resistors (with 7 cells, a
string of 20Ω voltage divider resistors, and 39Ω cell
balancing resistors, turning on one cell balance output
drops the voltage on that cell to less than 2.5V. At this
voltage, the microcontroller puts the ISL9208 to sleep).
the maximum cell voltage exceeds the cell with the
off the cell balance and the power FETs if the temperature
is too high or low.
enabled through the GUI).
these voltages to the GUI.
– If Li-ion cells are being used, discharge the pack until
– If one power supply is being used, lower the voltage
– If seven power supplies are used, then simply
one or more of the cells reach the undervoltage limit
and the discharge FET turns off. Then, charge the
pack until the FETs turn on again and continue
charging until a cell overvoltage condition is reached.
on the power supply until one or more of the cells
reach the undervoltage limit and the discharge FET
turns off. Then, increase the voltage until the FETs turn
on again and continue increasing the voltage until a
cell overvoltage condition is reached.
decrease or increase any individual supply until the
thresholds are reached and the FET turns off (or on).
December 15, 2008
AN1444.0