5 VDD V- 2
6 VSS DOUT 1
FUSE NEXT TO Q1
ON PCB LAYOUT
Note: Connect NTC pin to ground if thermister is not used
FIGURE 1. ISL6295 APPLICATIONS SCHEMATIC
Functional Pin Descriptions
GPAD/IO1 (Pin 1)
General purpose A/D input or general purpose input/output
pin. Grounded if not used.
VP (Pin 2)
Cell input connection for the positive terminal of the Li-Ion
cell. Connects to the positive terminal of 1-cell series packs.
VP serves as the power supply input for the ISL6295.
SCL (Pin 3)
SMBus/I2C™ clock line connection
SDA (Pin 4)
SMBus/I2C™ data line connection
ROSC (Pin 5)
External bias resistor. 221kΩ (±0.1%) oscillator reference
setting resistor connected between this pin and GND.
NTC/IO0 (Pin 6)
Connection for an external temperature sensor using a
thermistor. Can also be configured as an open drain general
purpose input/output pin. Grounded if not used.
GND (Pin 7)
Analog and digital ground
SR (Pin 8)
Current measurement A/D input. Connects to the other
terminal of a grounded current sense resistor.
Theory of Operation
The ISL6295 contains a complete analog "front-end" for
battery monitoring as well as digital logic for control,
measurement accumulation, timing, and communications.
Major functions within the ISL6295 include:
• Voltage Regulator
• Precision Time Base
• Temperature Sensor
• 256 Byte NV-EEPROM
• 32 Byte general purpose SRAM
• Analog-to-Digital (A/D) Converter
• 32-bit Accumulators/Timers
• SMBus/I2C™ Communications Interface
Figure 2 is a block diagram of the internal circuitry of the
ISL6295. Figure 1 is a schematic diagram that depicts the
ISL6295 in a typical single cell Lithium-ion application. The
function of each of the blocks listed above is summarized in
the following sections.
October 25, 2005