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Selectable overvoltage (V
OV
)
thresholds
General Description
The bq2058 Lithium Ion Pack Super-
visor is designed to control the charge
and discharge cell voltages for three or
four lithium ion (Li-Ion) series cells,
accommodating battery packs contain-
ing series/parallel configurations. The
low operating current does not over-
discharge the cells during periods of
storage and does not significantly in-
crease the system discharge load. The
bq2058 can be part of a low-cost Li-Ion
charge control system within the bat-
tery pack.
The bq2058 controls two external FETs
to limit the charge and discharge poten-
tials. The bq2058 allows charging when
each individual cell voltage is below V
OV
(overvoltage limit). If the voltage on any
cell exceeds V
OV
for a user-configurable
delay period (t
OVD
), the
CHG pin is
driven high, shutting off charge to the
battery pack. This safety feature pre-
vents overcharge of any cell within
the battery pack. After an overvolt-
age condition occurs, each cell must
fall below V
CE
(charge enable voltage)
for the bq2058 to re-enable charging.
The bq2058 protects batteries from
overdischarge. If the voltage on any
cell falls below V
UV
(undervoltage
limit) for a user-configurable delay pe-
riod (t
UVD
), the DSG output is driven
high, shutting off the battery dis-
charge. This safety feature prevents
overdischarge of any cell within the
battery pack.
The bq2058 also stops discharge on
detection of an overcurrent condition,
such as a short circuit. If an overcur-
rent condition occurs for a user-
configurable delay period (t
OCD
), the
DSG output is driven high, disconnect-
ing the load from the pack. DSG re-
mains high until removal of the short
circuit or overcurrent condition.
-
-
Mask-programmable by
Unitrode
Standard version鈥?.25V
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Supply current: 25碌A(chǔ) typical
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Sleep current: 0.7碌A(chǔ) typical
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16-pin 150-mil narrow SOIC
Pin Connections
Pin Names
CHG
Charge control output
Pack disable input
Low potential input
Current sense low-side
input
Battery 4 negative input
Battery 3 negative input
Battery 2 negative input
Battery 1 negative input
BAT
1P
DSG
NSEL
UVD
OVD
OCD
V
CC
CSH
Discharge control output
3- or 4-cell selection
Undervoltage delay input
Overvoltage delay input
Overcurrent delay input
High potential input
Current sense high-side
input
Battery 1 positive input
CHG
CTL
VSS
CSL
BAT4N
BAT3N
BAT2N
BAT1N
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
DSG
NSEL
UVD
OVD
OCD
VCC
CSH
BAT1P
CTL
V
SS
CSL
BAT
4N
BAT
3N
BAT
2N
16-Pin Narrow SOIC
PN205801.eps
BAT
1N
1/99 I
1
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