BQ2052_15 Datasheet, PDF (10/20 Pages) Texas Instruments – Gas Gauge IC

Not Recommended For New Designs
bq2052 Preliminary
Primary Status Flags Register (FLGS1)
The FLGS1 register (address = 01h) contains the pri-
mary bq2052 flags.
The initialized flag (INIT) is asserted to a 1 or 0 when-
ever the bq2052 is initialized either by the application of
Vcc or by a serial port command. INIT = 1 signifies that
the device has been reset with FNAC set to PFC. INIT = 0
signifies that the battery has been reset with FNAC = 0.
The INIT location is:
FLGS1 Bits
7 65 4
3
2
INIT -
-
-
-
-
1
0
-
-
where INIT is:
0 The bq2052 initialized with FNAC = 0.
1 The bq2052 initialized with FNAC = PFC.
The CPIN but reflects the state of the CP output. If set,
the CP output is high impedance. If cleared, the CP out-
put is asserted low. The CP output is an open drain out-
put and requires an external pull-up register.
The CPIN location is
FLGS1 Bits
7
6
5
4
3
2
1
0
-
-
- CPIN -
-
-
-
Where CPIN is:
0 CP is low
1 CP is high impedance
The bq2052 sets the first end-of-discharge warning
flag (EDV1) when the battery voltage VSB is less than
the EDV1 threshold VTS. The flag warns the user that
the battery is almost empty. The bq2052 modulates the
first segment pin, SEG1, at a 4Hz rate if the 4 or 5 seg-
ment display mode is enabled and EDV1 is asserted.
The EDV1 threshold has a default value of 0.76V but
can be adjusted by writing the VTS register .
The EDV1 location is
FLGS1 Bits
7 65 4
3
2
1
0
-
--
-
-
- EDV1 -
Where EDV1 is:
0 V_SB ≥ V_TS
1 V_SB < V_TS
The bq2052 sets the final end-of-discharge warning
flag (EDVF) when VSB is less than the EDVF threshold.
The EDVF threshold is set 100mV below the EDV1
threshold. The EDVF flag is used to warn the system or
user that battery power is at a failure condition. The
bq2052 turns all segment drivers off upon EDVF detec-
tion.
The EDVF location is:
FLGS1 Bits
7 65 4
3
2
1
0
-
--
-
-
-
- EDVF
Where EDVF is:
0 V_SB ≥ (V_TS - 100mV)
1 V_SB < (V_TS -100mV)
Temperature Register (TEMP)
The 8-bit TEMP register (address=02h) contains the
battery temperature in degrees C. The bq2052 contains
an internal temperature sensor. The temperature is
used to set discharge efficiency factors. The temperature
register contents are store in 2’s complement form and
represent the temperature ± 5°C.
Nominal Available Capacity Register (NAC)
The NAC register contains the uncompensated remaining
capacity of the battery. The bq2052 determines NAC as
NAC = FNAC - DCR
Battery Identification Register (BATID)
The 8-bit BATID register (address=04h) is a general
purpose memory register that can be used to uniquely
identify a battery pack. The bq2052 maintains the
BATID contents as long as VRBI is greater than 2V. The
contents of this register have no effect on the operation
of the bq2052.
Current Scale Registers (VSRL/VSRH)
The VSRH high-byte register and the VSRL low-byte
register are used to calculate the average signal across
the SR and VSS pins. This register pair is updated ev-
ery 5.625 seconds. VSRH and VSRL form a 16-bit value
representing the average current over this time. The
battery pack current can be calculated by:
|I(mA)| = ^{(VSRH ∗ 256 + VSRL)}
(RS)
10