bq2060
SBS v1.1-Compliant Gas Gauge IC
Features
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Provides accurate measurement
of available charge in NiCd,
NiMH, Li-Ion, and lead-acid
batteries
Supports SBS Smart Battery
Data Specification v1.1
Supports the 2-wire SMBus v1.1
interface with PEC or 1-wire
HDQ16
Reports individual cell voltages
Monitors and provides control to
charge and discharge FETs in
Li-Ion protection circuit
Provides 15-bit resolution for
voltage, temperature, and cur-
rent measurements
Measures charge flow using a
V-to-F converter with offset of
less than 16碌V after calibration
Consumes less than 0.5mW oper-
ating
Drives a 4- or 5-segment LED
display for remaining capacity in-
dication
28-pin 150-mil SSOP
General Description
The bq2060 SBS-Compliant Gas
Gauge IC for battery pack or
in-system installation maintains an
accurate record of available charge in
rechargeable batteries. The bq2060
monitors capacity and other critical
battery parameters for NiCd, NiMH,
Li-Ion, and lead-acid chemistries.
The bq2060 uses a V-to-F converter
with automatic offset error correction
for charge and discharge counting.
For voltage, temperature, and current
reporting, the bq2060 uses an A-to-D
converter. The onboard ADC also
monitors individual cell voltages in a
Li-Ion battery pack and allows the
bq2060 to generate control signals
that may be used in conjunction with
a pack supervisor to enhance pack
safety.
The bq2060 supports the smart bat-
tery data (SBData) commands and
charge-control functions. It communi-
cates data using the system manage-
ment bus (SMBus) 2-wire protocol or
the Benchmarq 1-wire HDQ16 proto-
col. The data available include the
battery鈥檚 remaining capacity, temper-
ature, voltage, current, and remain-
ing run-time predictions. The bq2060
provides LED drivers and a
push-button input to depict remaining
battery capacity from full to empty in
20% or 25% increments with a 4 or
5-segment display.
The bq2060 works with an external
EEPROM. The EEPROM stores the
configuration information for the
bq2060, such as the battery鈥檚 chemis-
try, self-discharge rate, rate compen-
sation factors, measurement calibra-
tion, and design voltage and capacity.
The bq2060 uses the programmable
self-discharge rate and other compen-
sation factors stored in the EEPROM
to accurately adjust remaining capac-
ity for use and standby conditions
based on time, rate, and temperature.
The bq2060 also automatically cali-
brates or learns the true battery ca-
pacity in the course of a discharge cy-
cle from near full to near empty lev-
els.
The REG output regulates the operat-
ing voltage for the bq2060 from the
battery cell stack using an external
JFET.
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Pin Connections
HDQ16
ESCL
ESDA
RBI
REG
V
OUT
V
CC
V
SS
DISP
LED
1
LED
2
LED
3
LED
4
LED
5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
SMBC
SMBD
VCELL
4
VCELL
3
VCELL
2
VCELL
1
SR
1
SR
2
SRC
TS
THON
CVON
CFC
DFC
Pin Names
HDQ16
Serial communication
input/output
Serial memory clock
Serial memory data and
address
Register backup input
Regulator output
EEPROM supply output
Supply voltage
Ground
Display control input
LED display segment outputs
DFC
CFC
VON
trol
THON
TS
SRC
SR
1
鈥?/div>
SR
2
Discharge FET control
Charge FET control
Cell voltage divider con-
ESCL
ESDA
Thermistor bias control
Thermistor voltage input
Current sense input
Charge-flow sense resistor
inputs
RBI
REG
V
OUT
V
CC
V
SS
DISP
VCELL
1
鈥?Single-cell voltage inputs
VCELL
4
SMBD
SMBC
SMBus data
SMBus clock
28-Pin 150-mil SSOP
28PN2060.eps
LED
1
鈥?/div>
LED
5
SLUS035D鈥揝EPTEMBER 2001
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