ISL9216IRZ Intersil, ISL9216IRZ Datasheet - Page 24

• Manufacturer Part Number: ISL9216IRZ
• Description: IC MULTI-CELL LI-ION PROT 32-QFN
• Manufacturer: Intersil

Specifications of ISL9216IRZ

• Function: Battery Monitor
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 9.2 V ~ 31 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

In the event of an automatic over-temperature condition, cell
balancing is prevented and FETs are held off until the
temperature drops back below the temperature recovery
threshold. During this temperature shutdown period, the
microcontroller can monitor the internal temperature through
the analog output pin (AO), but any writes to the CFET bit,
DFET bit, or cell balancing bits are ignored
The automatic response to an internal over-temperature is
prevented by setting the DISITSD bit to “1”. The automatic
response to an external over-temperature is prevented by
setting the DISXTSD bit to “1”. In either case, it is important
for the microcontroller to monitor the internal and external
temperature to protect the pack and the electronics in an
over-temperature condition.
Analog Multiplexer Selection
The ISL9216 and ISL9217 devices can be used to externally
monitor individual battery cell voltages and temperatures.
Each quantity can be monitored at the analog output pin (AO)
and is selected using the I
To monitor the voltages on the ISL9217 inputs, set the
ISL9216 to monitor VCELL6, then set the ISL9217 to the
desired VCELL input. The ISL9216 and ISL9217 VCELL
input voltages are divided by 2, except for the ISL9216
VCELL6 input. This is a divide by 1 input. In this way, the
value read at the ISL9216 AO output is always a divide by 2
of the original cell voltage.
VOLTAGE MONITORING
Since the voltage on each of the Li-Ion Cells are normally
higher than the regulated supply voltage, it is necessary to
both level shift and divide the voltage. To get into the voltage
range required by the external A/D converter, the voltage
level shifter divides the cell voltage by 2. Therefore, a Li-Ion
cell with a voltage of 4.2V is reported via the AO pin to be
2.1V.
TEMPERATURE MONITORING
The voltage representing the external temperature applied at
the TEMPI terminal is directed to the AO terminal through a
MUX, as selected by the AO control bits (see Figures 5
and 6). The external temperature voltage is not divided by 2
as are the cell voltages. Instead it is a direct reflection of the
voltage at the TEMPI pin.
A similar operation occurs when monitoring the internal
temperature through the AO output, except there is no
external “calibration” of the voltage associated with the
internal temperature. For the internal temperature
monitoring, the voltage at the output is linear with respect to
temperature. (See “Operating Specifications” on page 6 for
information about the output voltage at +25°C and the output
slope relative to temperature).
2
C interface. See Figure 6.
24
ISL9216, ISL9217
Cell Balancing
OVERVIEW
A typical ISL9216 and ISL9217 Li-ion battery pack consists
of 8 to 12 cells in series, with one or more cells in parallel.
This combination gives both the voltage and power
necessary for power tools, e-bikes, electric wheel chairs,
portable medical equipment, and battery powered industrial
applications. While the series/parallel combination of Li-ion
cells is common, the configuration is not as efficient as it
could be, because any capacity mismatch between series-
connected cells reduces the overall pack capacity. This
mismatch is greater as the number of series cells and the
load current increase. Cell balancing techniques increase
the capacity and the operating time of Li-ion battery packs.
FIGURE 6. ANALOG OUTPUT MONITORING DIAGRAM
SCL
SDA
AO
AO
LEVEL
SHIFT
AO3:AO0
AO3:AO0
2
1
2
1
DECODE
DECODE
REGS
REGS
MUX
MUX
I
I
2
2
C
C
ISL9217
ISL9216
LEVEL
LEVEL
EXT TEMP.
LEVEL
LEVEL
LEVEL
SHIFT
SHIFT
SHIFT
SHIFT
SHIFT
LEVEL
LEVEL
LEVEL
SHIFT
SHIFT
SHIFT
TEMP
TEMP
INT
INT
VCELL6
VSS
VSS
VCELL5
VCELL4
VCELL1
VCC
VC7/VCC
VCELL6
VCELL2
VCELL1
TEMPI
(ISL9216 ONLY)
November 2, 2007
FN6488.1