BQ2052_15 Datasheet, PDF (12/20 Pages) Texas Instruments – Gas Gauge IC

Not Recommended For New Designs
bq2052 Preliminary
In incremental mode (PROG₅ = L), the battery charge
state is displayed on pins SEG1–SEG4. The charge state
condition indicated by each segment is shown in Table 7.
Only the segment pin representing the present remain-
ing capacity is ON (low); all other segments are OFF
(high impedance). When DISP is pulled low, the display
is active for 10s.
Table 7. Incremental Display Mode
PROG₅ = L
SEG Pin ON
SEG4
SEG3
SEG2
SEG1
SEG1—BLINK
Remaining Capacity
90 -100%
50 - < 90%
20 - < 50%
< 20%
V_SB < V_EDV1
In binary mode (PROG5 = H), the battery charge state is
displayed using only pins SEG1 and SEG2, with the re-
maining capacity indication defined as in Table 8. When
DISP is pulled low, the display is active for 4s.
Table 8. Binary Display Mode
PROG₅ = H
SEG 1
ON
ON
OFF
OFF
SEG 2
ON
OFF
ON
OFF
Remaining Capacity
70 -100%
40 - < 70%
10 - < 40%
< 10% or V_SB < V_EDVF
Microregulator
A micro-power source for the bq2052 can be inexpen-
sively built using a FET and an external resistor as
shown in Figure 1.
RBI Input
The RBI input pin should be used with a storage capaci-
tor or external supply to provide backup potential to the
internal bq2052 registers when V_CC drops below 3.0V.
V_CC is output on RBI when V_CC is above 3.0V. If using
an external supply (such as the bottom series cell) as the
backup source, an external diode is required for isola-
tion.
Initialization
The bq2052 can be initialized by removing VCC and
grounding the RBI pin for 5s or by a command over the
serial port. The serial port reset command requires
writing 78h to register CMDWD (address = 00h).
On initialization with PROG6 = H, the bq2052 sets the
registers as
FNAC = PFC
CACH = PFC
CACL = 0x00
RCAC = 0x64
FLGS1 = 0x90
In bar graph mode (PROG₅ = Z), the battery charge
state is displayed using pins SEG1 through SEG 5 ac-
cording to Table 9. When DISP is pulled low, the display
is active for 4s.
SEG1
ON
ON
ON
ON
ON
BLINK
SEG2
ON
ON
ON
ON
OFF
OFF
Table 9. Bar Graph Display Mode
PROG₅ = Z
SEG3
ON
ON
ON
OFF
OFF
OFF
SEG4
ON
ON
OFF
OFF
OFF
OFF
SEG5
ON
OFF
OFF
OFF
OFF
OFF
Remaining Capacity
80 - 100%
60 - < 80%
40 - < 60%
20 - < 40%
< 20%
VSB < VEDV1
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