BQ34Z100 Datasheet, PDF (20/50 Pages) Texas Instruments – Wide Range Fuel Gauge with Impedance Track™ Technology

bq34z100
SLUSAU1 – MAY 2012
www.ti.com
SLEEP: The fuel gauge can enter sleep, if operating conditions allow. True when set.
Default is 1.
RMFCC: RM is updated with the value from FCC, on valid charge termination. True
when set. Default is 1.
RSVD: Reserved. Do not use.
TEMPS: Selects external thermistor for Temperature() measurements. True when set.
Uses internal temp when clear. Default is 1
TEMPERATURE MEASUREMENT
The bq34z100 can measure temperature via the on-chip temperature sensor or via the TS input depending on
the setting of the [TEMPS] bit PackConfiguration(). The bit is set by using the PackConfiguration() function,
described in EXTENDED DATA COMMANDS.
Temperature measurements are made by calling the Temperature() function (see STANDARD DATA
COMMANDS for specific information).
When an external thermistor is used, REG25 (pin 7) is used to bias the thermistor and TS (pin 11) is used to
measure the thermistor voltage (a pull-down circuit is implemented inside the bq34z100). The bq34z100 then
correlates the voltage to temperature, assuming the thermistor is a Semitec 103AT or similar device.
OVER-TEMPERATURE INDICATION
Over-Temperature: Charge
If during charging, Temperature() reaches the threshold of DF:OT Chg for a period of OT Chg Time and
AverageCurrent() > Chg Current Threshold, then the [OTC] bit of Flags() is set. Note: if OT Chg Time = 0 then
feature is completely disabled.
When Temperature() falls to OT Chg Recovery, the [OTC] of Flags() is reset.
Over-Temperature: Discharge
If, during discharging, Temperature() reaches the threshold of OT Dsg for a period of OT Dsg Time, and
AverageCurrent() ≤ –Dsg Current Threshold, then the [OTD] bit of Flags() is set.
NOTE
If OT Dsg Time = 0, then the feature is completely disabled.
When Temperature() falls to OT Dsg Recovery, the [OTD] bit of Flags() is reset.
CHARGING AND CHARGE TERMINATION INDICATION
For proper bq34z100 operation, the battery charging voltage must be specified by the user. The default value for
this variable is Charging Voltage = 4200 mV. This parameter should be set to the recommended charging
voltage for the entire battery stack.
The bq34z100 detects charge termination when (1) during two consecutive periods of Current Taper Window, the
AverageCurrent() is < Taper Current and (2) during the same periods, the accumulated change in capacity >
0.25 mAh /Taper Current Window and (3) Voltage() > Charging Voltage - Charging Taper Voltage. When this
occurs, the [CHG] bit of Flags() is cleared. Also, if the [RMFCC] bit of Pack Configuration is set, and
RemainingCapacity() is set equal to FullChargeCapacity().
20
Submit Documentation Feedback
Product Folder Link(s): bq34z100
Copyright © 2012, Texas Instruments Incorporated