BQ20Z45-R1 Datasheet, PDF (13/18 Pages) Texas Instruments – SBS 1.1-Compliant Gas Gauge and Protection Enabled With Impedance Track™

bq20z45-R1
www.ti.com
SLUS992 – DECEMBER 2009
Voltage
The bq20z45-R1 updates the individual series cell voltages at one second intervals. The internal ADC of the
bq20z45-R1 measures the voltage, scales and calibrates it appropriately. This data is also used to calculate the
impedance of the cell for the Impedance Track™ gas-gauging.
Current
The bq20z45-R1 uses the SRP and SRN inputs to measure and calculate the battery charge and discharge
current using a 5 mΩ to 20 mΩ typ. sense resistor.
Auto Calibration
The bq20z45-R1 provides an auto-calibration feature to cancel the voltage offset error across SRN and SRP for
maximum charge measurement accuracy. The bq20z45-R1 performs auto-calibration when the SMBus lines stay
low continuously for a minimum of 5 s.
Temperature
The bq20z45-R1 has an internal temperature sensor and inputs for 2 external temperature sensor inputs TS1
and TS2 used in conjunction with two identical NTC thermistors (default are Semitec 103AT) to sense the battery
environmental temperature. The bq20z45-R1 can be configured to use internal or up to 2 external temperature
sensors.
Copyright © 2009, Texas Instruments Incorporated
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