BQ27750 Datasheet, PDF (23/34 Pages) Texas Instruments – Impedance Track Battery Gas Gauge and Protection Solution for 1-Series Cell Li-Ion Battery Packs

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bq27750
SLUSCM7 – JUNE 2017
Each parameter listed for fault trigger thresholds has a delay timer setting associated for any noise filtering.
These values, along with the trigger thresholds for fault detection, may be changed based upon the application
requirements using the data flash settings in the appropriate register stated in the bq27750 Technical Reference
Manual (SLUUBI6).
8.2.3 Calibration Process
The calibration of current, voltage, and temperature readings is accessible by writing 0xF081 or 0xF082 to
ManufacturerAccess(). A detailed procedure is included in the bq27750 Technical Reference Manual (SLUUBI6)
in the Calibration section. The description allows for calibration of Cell Voltage Measurement Offset, Battery
Voltage, Pack Voltage, Current Calibration, Coulomb Counter Offset, PCB Offset, CC Gain/Capacity Gain, and
Temperature Measurement for both internal and external sensors.
8.2.4 Gauging Data Updates
When a battery pack enabled with the bq27750 gas gauge is first cycled, the value of FullChargeCapacity()
updates several times. Figure 21 shows RemainingCapacity() and FullChargeCapacity(), and where those
updates occur. As part of the Impedance Track algorithm, it is expected that FullChargeCapacity() may update at
the end of charge, at the end of discharge, and at rest.
8.2.4.1 Application Curve
Figure 21. Elapsed Time(s)
9 Power Supply Requirements
There are two inputs for this device, the PACK input and BAT. The PACK input can be an unregulated input from
a typical AC adapter. This input should always be greater than the maximum voltage associated with the number
of series cells configured. The input voltage for the BAT pin will have a minimum of 2.2 V to a maximum of 26 V
with the recommended external RC filter.
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