BQ27210 Datasheet, PDF (14/30 Pages) Texas Instruments – Li-Ion AND Li-Pol BATTERY GAS GAUGE IC FOR PORTABLE APPLICATIONS (bqJUNIOR)

bq27010, bq27210
SLUS707B – APRIL 2006 – REVISED JANUARY 2007
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the offset of the DSCC with an internal short applied from SRP to SRN. The result can be read in
0x5f-5e. The result is a signed number with an LSB value of 1.225 µV. The command takes
approximately 5.5 seconds to make the measurement. This command is intended for
manufacturing use, along with the CEO command, to determine the external board offset..
WNACCI WNACCI is used to transfer data from the AR registers to NAC. It is identical to the WRTNAC
command, but the CI bit in FLAGS is also cleared
The following commands are intended for use by a host-side gauge if the battery pack is changed and the host
can determine that the new pack requires different values loaded into the gauge. They can also be used with a
pack-side gauge if the default EEPROM values in the bqJUNIOR do not match the required values. If the host
only desires to change one of the bytes, the value for the unchanging byte will still have to be read and placed in
the appropriate AR byte, as both bytes will be updated when the command is issued. The EEPROM values used
by the bq27x010 firmware are located in addresses 0x46 to 0x4F. These addresses are a mirror of the
EEPROM values programmed in addresses 0x76 to 0x7F after a full reset, unless DCOMP and/or TCOMP
default values are selected by PKCFG[1:0]. Update commands for the EEPROM coefficients will update the
appropriate value in the 0x46 to 0x4F address space, but will not affect the value in the 0x76 to 0x7F addresses.
WRTCYC WRTCYC is used to transfer data from the AR registers to CYCT.
WRTLMD WRTLMD is used to transfer data from the AR registers to LMD.
UPDC
UPDC is used to simultaneously update the ILMD value (DC) from the ARL register and to update
the EDVF value from the ARH register.
UPEDV1 UPEDV1 is used to simultaneously update the EDV1 value from the ARL register and to update
the ISLC/EDVT value from the ARH register.
UPDMF
UPDMF is used to simultaneously update the DMFSD value from the ARL register and to update
the TAPER value from the ARH register.
UPCFG
UPCFG is used to simultaneously update the PKCFG value from the ARL register and to update
the GAF/DEDV value from the ARH register.
UPCOMP UPCOMP is used to simultaneously update the DCOMP value from the ARL register and to update
the TCOMP value from the ARH register.
At-Rate Registers (ARL/ARH) — Address 0x02/0x03
The host can write the current in units of 3.57 µV per bit to this register for predictive calculation time-to-empty.
The part uses this value to predict the time-to-empty at any desired current; it does not affect the time-to-empty
calculation based on the actual current. The value in AR is always assumed to be a discharge current.
This register is also used during pack manufacturing to input a nominal available-charge value to set NAC to the
approximate initial pack capacity value, and to update other values as described in the CTRL register
description.
At Rate Time-to-Empty Registers (ARTTEL/ARTTEH) — Address 0x04/0x05
This is predicted time-to-empty in minutes at user-entered discharge rate. The discharge current used in the
calculation is entered by the host system in the AR registers. The at-rate capacity (ARCAP) value used can be
larger or smaller than CAC. It is computed using the same compensation formulas as CAC, except the
discharge compensation is computed using AR, instead of AI, for the discharge rate. The equation used to
compute at-rate time-to-empty is:
ARTTE = 60 * ARCAP / AR
The host system has read-only access to this register pair.
Reported Temperature Registers (TEMPL/TEMPH) — Address 0x06/0x07
The TEMPH and the TEMPL registers contain the reported die temperature. The temperature is expressed in
units of 0.25 °K and is updated every 2.56 seconds. The equation to calculate reported pack temperature is:
Temperature = 0.25 * (256 * TEMPH + TEMPL)
The host system has read-only access to this register pair.
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