BQ2016 Datasheet, PDF (8/21 Pages) Texas Instruments – GAS GAUGE IC FOR HIGH DISCHARGE RATES

bq2016
GAS GAUGE IC FOR
HIGH DISCHARGE RATES
SLUS475A– JANUARY 2001 – REVISED NOVEMBER 2002
functional description (continued)
Inputs
Charge
Current
Rate and
Temperature
Compensation
Discharge
Current
Rate and
Temperature
Compensation
Self-Discharge
Timer
Temperature
Compensation
Main Counters and
Capacity Reference (LMD)
––
Nominal
Last
+
Available
Charge
≤
Measured
Discharge
(NAC)
(LMD)
Qualified
Transfer
++
Discharge
Count
Register
(DCR)
Temperature
Translation
Temperature, Voltage,
Other Data
Outputs
Chip-Controlled
Available Charge
LED Display
Serial
Port
Figure 5. Operational Overview Diagram
main gas gauge registers
programmed full count (PFC)
The programmed full count (PFC) register stores the user-specified battery full capacity. The 8-bit PFC registers
stores the full capacity in mVh scaled as shown in Table 2. The VPFC input sets the PFC value and the counting
scale on a bq2016 initialization (power on reset).
nominal available capacity (NAC)
The main counter, NAC, represents the available battery capacity at any given time. Battery charging
increments the NAC register, while battery discharging and self-discharge decrement the NAC register. The
bq2016 compensates the charge and discharge inputs to NAC for rate and temperature efficiencies.
NAC counts up during charge to a maximum value of LMD and down during discharge and self-discharge to
0. The bq2016 resets NAC to 0 on initialization and when the bq2016 sets the EDV bit on discharge. To prevent
overstatement of charge during periods of overcharge, NAC stops incrementing when NAC = LMD.
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