BQ2010_15 Datasheet, PDF (1/26 Pages) Texas Instruments – Gas Gauge IC

Not Recommended For New Designs
bq2010
Gas Gauge IC
Features
➤ Conservative and repeatable
measurement of available charge
in rechargeable batteries
➤ Designed for battery pack inte-
gration
- 120µA typical standby current
- Small size enables imple-
mentations
in
as
little
as
1
2
square inch of PCB
➤ Integrate within a system or as a
stand-alone device
- Display capacity via single-
wire serial communication
port or direct drive of LEDs
➤ Measurements compensated for
current and temperature
➤ Self-discharge compensation us-
ing internal temperature sensor
➤ Accurate measurements across a
wide range of current (> 500:1)
➤ 16-pin narrow SOIC
General Description
The bq2010 Gas Gauge IC is intended
for battery-pack or in-system installa-
tion to maintain an accurate record of
a battery's available charge. The IC
monitors a voltage drop across a
sense resistor connected in series be-
tween the negative battery terminal
and ground to determine charge and
discharge activity of the battery.
NiMH and NiCd battery self-dis-
charge is estimated based on an inter-
nal timer and temperature sensor.
Compensations for battery tempera-
ture and rate of charge or discharge
are applied to the charge, discharge,
and self-discharge calculations to pro-
vide available charge information
across a wide range of operating con-
ditions. Battery capacity is automati-
cally recalibrated, or “learned,” in the
course of a discharge cycle from full to
empty.
Nominal available charge may be
directly indicated using a five- or
six-segment LED display. These seg-
ments are used to indicate graphi-
cally the nominal available charge.
The bq2010 supports a simple
single-line bidirectional serial link to
an external processor (common
ground). The bq2010 outputs battery
information in response to external
commands over the serial link.
The bq2010 may operate directly
from 3 or 4 cells. With the REF out-
put and an external transistor, a sim-
ple, inexpensive regulator can be built
to provide V_CC across a greater
number of cells.
Internal registers include available
charge, temperature, capacity, battery
ID, battery status, and programming
pin settings. To support subassembly
testing, the outputs may also be con-
trolled. The external processor may
also overwrite some of the bq2010
gas gauge data registers.
Pin Connections
LCOM
1
SEG1/PROG1
2
SEG2/PROG2
3
SEG3/PROG3
4
SEG4/PROG4
5
SEG5/PROG5
6
SEG6/PROG6
7
VSS
8
16
VCC
15
REF
14
NC
13
DQ
12
EMPTY
11
SB
10
DISP
9
SR
16-Pin Narrow SOIC
PN201001.eps
4/95 D
Pin Names
LCOM
LED common output
SEG₁/PROG₁ LED segment 1/
program 1 input
SEG₂/PROG₂ LED segment 2/
program 2 input
SEG₃/PROG₃ LED segment 3/
program 3 input
SEG₄/PROG₄ LED segment 4/
program 4 input
SEG₅/PROG₅ LED segment 5/
program 5 input
SEG₆/PROG₆ LED segment 6/
program 6 input
REF
NC
DQ
EMPTY
SB
DISP
SR
V_CC
V_SS
Voltage reference output
No connect
Serial communications
input/output
Empty battery indicator
output
Battery sense input
Display control input
Sense resistor input
3.0–6.5V
System ground
1