A capacitor of a value of at
least 2.2 µF is connected between the VDD pin and VSS. The
capacitor should be placed close to the gauge IC and have short traces to both
the VDD pin and VSS. This regulator must not be used to
provide power for other devices in the system.
It is required to have a
capacitor of at least 1.0 µF connect between the BAT pin and VSS if
the connection between the battery pack and the gauge BAT pin has the potential
to pick up noise. The capacitor should be placed close to the gauge IC and have
short traces to both the VDD pin and VSS.
If the external pullup resistors
on the SCL and SDA lines will be disconnected from the host during low-power
operation, it is recommended to use external 1-MΩ pulldown resistors to
VSS to avoid floating inputs to the I2C engine.
The value of the SCL and SDA
pullup resistors should take into consideration the pullup voltage and the bus
capacitance. Some recommended values, assuming a bus capacitance of 10 pF, can
be seen in Table 10-1.
Table 10-1 Recommended Values for
SCL and SDA Pullup Resistors
VPU
1.8 V
3.3 V
RPU
Range
Typical
Range
Typical
400 Ω ≤ RPU ≤ 37.6 kΩ
10 kΩ
900 Ω ≤ RPU ≤ 29.2 kΩ
5.1 kΩ
If the host is not using the
GPOUT functionality, then it is recommended that GPOUT be connected to a GPIO of
the host so that in cases where the device is in SHUTDOWN, toggling GPOUT can
wake the gauge up from the SHUTDOWN state.
If the battery pack thermistor is
not connected to the BIN pin, the BIN pin should be pulled down to
VSS with a 10-kΩ resistor.
The BIN pin should not be shorted
directly to VDD or VSS.
The actual device ground is pin 3
(VSS).
The SRP and SRN pins should be
Kelvin connected to the RSENSE terminals. SRP to the battery pack
side of RSENSE and SRN to the system side of the
RSENSE.
Kelvin connects the BAT pin to
the battery PACKP terminal.