BQ2060SS Datasheet, PDF (24/59 Pages) Texas Instruments – SBS V1.1-COMPLIANT GAS GAUGE IC

bq2060
SLUS035E – JANUARY 2000 – REVISED OCTOBER 2005
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• RemainingCapacityAlarm()
• AtRate()
• RemainingCapacity()
• FullChargeCapacity()
• DesignCapacity()
NOTE 2: The following functions are calculated on the basis of capacity and may be calculated differently
depending on the CAPACITY_MODE bit:
• AtRateOK()
• AtRateTimeToEmpty()
• AtRateTimeToFull()
• RunTimeToEmpty()
• AverageTimeToEmpty()
• AverageTimeToFull()
• Remaining Time Alarm()
• BatteryStatus()
The bq2060 updates the non-AtRate related register values within 3 s of changing the state of the CAPACITY_
MODE bit. The AtRate() values is updated after the next AtRate value is written to the bq2060 (or after the next
20-s scheduled refresh calculation).
AtRate() (0x04); [0x04]
DESCRIPTION
The AtRate() function is the first half of a two-function call-set used to set the AtRate value used in
calculations made by the AtRateTimeToFull(), AtRateTime-ToEmpty(), and AtRateOK() functions.
The AtRate value may be expressed in either current (mA) or power (10 mWh) depending on the
setting of the BatteryMode()’s CAPACITY_MODE bit.
PURPOSE
Because the AtRate() function is the first half of two-function call-set, it is followed by the second
function of the call-set that calculates and returns a value based on the AtRate value and the
battery’s present state. A delay of up to 1.3 s is required after writing AtRate() before the bq2060
can acknowledge the requested AtRate function.
• When the AtRate() value is positive, the AtRate-TimeToFull() function returns the predicted time to full
charge at the AtRate value of charge.
• When the AtRate() value is negative, the AtRateTimeToEmpty() function returns the predicted operating time
at the AtRate value of discharge.
• When the AtRate() value is negative, the AtRateOK() function returns a Boolean value that predicts the
battery’s ability to supply the AtRate value of additional discharge energy (current or power) for 10 seconds.
The default value for AtRate() is zero. Writing AtRate() values over the HDQ16 serial port does not trigger a
re-calculation of AtRateTimeToFull(), AtRateTimeToEmpty(), and AtRateOK() functions.
It is recommended that AtRate() requests should be limited to one request every 4 s.
SMBus PROTOCOL Read orWriteWord
INPUT/OUTPUT Signed integer—charge or discharge; the AtRate() value is positive for charge, negative for
discharge, and zero for neither (default).
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