Datasheet
Functional Description
General Operation
The bq2013H determines battery capacity by monitoring
the amount of charge input to or removed from a recharge-
able battery. The bq2013H measures discharge and charge
currents, estimates self-discharge, monitors the battery for
low-battery voltage thresholds, and compensates for tem-
perature and charge rates. The charge measurement is
made by monitoring the voltage across a small-value se-
ries sense resistor between the battery’s negative terminal
and ground. The available battery charge is determined
by monitoring this voltage over time and correcting the
measurement for the environmental and operating condi-
tions.
Figure 1 shows a typical battery pack application of the
bq2013H using the LED display. The bq2013H can be
configured to display capacity in either a relative or an
absolute display mode. The relative display mode uses
the last measured discharge capacity of the battery as
the battery “full” reference. The absolute display mode
uses the programmed full count (PFC) as the full refer-
ence, forcing each segment of the display to represent a
fixed amount of charge. A push-button display feature
is available for enabling the LED display.
The bq2013H monitors the charge and discharge cur-
rents as a voltage across a sense resistor (see R
S
in Fig-
ure 1). A filter between the negative battery terminal
and the SR pin is required.
3
bq2013H
FG2013H1.eps
PROG
6
SEG
5
/PROG
5
SEG
4
/PROG
4
SEG
3
/PROG
3
SEG
2
/PROG
2
SEG
1
/PROG
1
V
SS
DISP
SB
V
CC
REF
bq2013H
Gas Gauge IC
LCOM
RBI
HDQ
DONE
100K
Q1
ZVNL110A
R
1
C1
R
S
H, Z, or L
To µC
RB
1
0.1µF
RB
2
Load
Charger
To µC or
Fast Charger
2. The battery stack voltage can be directly connect to V
CC
across 4 nickel cells
(4.8V nominal and should not exceed 6.5V) with a resistor and a zener diode
to limit voltage during charge. Otherwise, R1and Q1 are needed for
regulation of > 4 nickel cells.
3. Programming resistors and ESD-protection diodes are not shown.
4. R-C on SR is required.
SR
1. Indicates optional.
Notes:
Figure 1. Application Diagram: LED Display