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Functional Description
Pulse Condition
Change of
(SOC Delta) ≠ 0
StateOfCharge()
BatteryStatus()
Always
[SYSDOWN] set
(SOC Delta) ≠ 0 and
Battery State Change
Operation Config B [INT_STATE] = 1
Operation Config A [BIEnable] = 1 and
Battery Removal
Operation Config B [INT_BREM] = 1
OCV measurement after
Operation Config B [INT_FOCV] = 1
initialization
OCV measurement
from OCV_CMD()
Operation Config B [INT_OCV] = 1
subcommand
BatteryStatus()[OTC or
Operation Config B [INT_OT] = 1
OTD]
BatteryStatus()[TDA]
Operation Config B [INT_BATL] = 1
4.2.4 Power Path Control With the BAT_GD Pin
The fuel gauge must operate in conjunction with other electronics in a system appliance, such as chargers or
other ICs and application circuits that draw appreciable power. After a battery is inserted into the system, it is
preferable that no charging current or discharging current higher than C/20 is present, so that an accurate OCV
can be read. The OCV reading determines the initial SOC so accuracy of the OCV reading directly impacts
the starting SOC. To disable these functions, the BAT_GD pin can be connected to the Charger Enable/Disable
(CE/CD) pin to disable the charging function. Once an OCV reading has been made, the BAT_GD pin is
asserted, thereby enabling battery charging and regular discharge of the battery. The Operation Config A
[BATG_POL] bit can change the polarity of the BAT_GD pin in case the default configuration needs to be
changed for the system application.
Figure 4-1
details how the BAT_GD pin functions in the context of battery insertion and removal, as well as
NORMAL versus SLEEP modes.
In PFC 1, the BAT_GD pin also disables battery charging when the fuel gauge reads battery temperatures
outside the range defined by [Charge Inhibit Temp Low, Charge Inhibit Temp High]. The BAT_GD line is
asserted once temperature falls within the range [Charge Inhibit Temp Low + Temp Hys, Charge Inhibit
Temp High – Temp Hys].
4.2.5 Battery Trip Point (BTP) Interrupts
The Battery Trip Point (BTP) feature provides the function to dynamically update capacity-based interrupt
thresholds using the BTPDischargeSet() and BTPChargeSet() commands. Two thresholds are supported:
one for crossings in the discharge direction (RemainingCapacity() < BTPDischargeSet()), and the other used
for the charge direction (RemainingCapacity() > BTPChargeSet()). When a given threshold is breached
in the correct current direction, the OperationStatus[BTPINT] flag will set to 1 and an interrupt triggered
on GPOUT. Afterwards, writing a new threshold value to either BTPDischargeSet() or BTPChargeSet()
will clear the OperationStatus[BTPINT] flag and de-assert the interrupt. The feature is enabled via
the Settings:Configuration:IO Config[BTP_EN] bit and the polarity of the interrupt configured using
Settings:Configuration:IO Config[BTP_POL] where setting to 1 selects active-high and clearing to 0
yields active-low assertion behavior on GPOUT. It should be further noted that the logic governing trigger
48
BQ27220
Table 4-6. SOC_INT Pulse Conditions and Widths
Enable Condition
1 ms
1 ms
1 ms
1 ms
Approximately
625 ms
If BATG_EN = 0, pulse
width = ~512 ms, else
pulse width = 380 ms
1 ms
1 ms
Copyright © 2022 Texas Instruments Incorporated
Pulse Width
During charge, when the SOC is greater than (>) the points:
100% – n × (SOC Delta) and 100%;
During discharge, when the SOC reaches (≤) the points: 100%
– n × (SOC Delta) and 0%;
where n is an integer starting from 0 to the number generating
SOC no less than 0%.
Examples:
For SOC Delta = 1% (default), the SOC_INT intervals are 0%,
1%, 2%, ..., 99%, and 100%.
For SOC Delta = 10%, the SOC_INT intervals are 0%, 10%,
20%, ..., 90%, and 100%.
When the Voltage() has reached SysDown Set Volt
Threshold
Upon detection of a state change in battery charging and
discharging
Within 1.5 seconds after a POR event, RESET() subcommand,
or battery insertion event (either via BATT_INSERT()
subcommand or battery present pin), SOC_INT begins a pulse
for the duration of the OCV measurement and initialization time
period.
Within 1 second after receipt of OCV_CMD() subcommand,
SOC_INT begins a pulse for the duration of the OCV
measurement execution time period.
Upon first assertion of BatteryStatus()[OTC or OTD]
overtemperature conditions
On change of BatteryStatus()[TDA]
SLUUBD4A – APRIL 2016 – REVISED NOVEMBER 2022
www.ti.com
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