Features
ä Complete bq2010 Gas Gauge solution for NiCd or
NiMH battery packs
ä Battery information available over a single-wire
bidirectional serial port
ä Battery state-of-charge monitoring for 4- to 12-cell
series applications
ä On-board regulator allows direct connection to the
battery
ä “L” version includes push-button activated LEDs to
display state-of-charge information
ä Nominal capacity and cell chemistry pre-configured
ä Compact size for battery pack integration
General Description
The bq2110 Gas Gauge Module provides a complete and
compact solution for capacity monitoring of NiCd and
NiMH battery packs. Designed for battery pack integra-
tion, the bq2110 incorporates a bq2010 Gas Gauge IC, a
current sense resistor, and all other components neces-
sary to accurately monitor and display the capacity of 4
to 12 series cells.
The bq2110L includes six surface-
mounted LEDs to display remaining capacity in 20% in-
crements of the learned capacity (relative mode) or pro-
grammed capacity (absolute mode). The sixth LED is
used in absolute mode to represent an overfull condition
(charge above the programmed capacity). The LEDs are
activated with the onboard push-button switch.
Contacts are provided on the bq2110 for direct connec-
tion to the battery stack (BAT+, BAT-), the serial com-
munications port (DQ), and the empty indicator
(EMPTY). Please refer to the bq2010 data sheet for the
specifics on the operation of the Gas Gauge.
Unitrode configures the bq2110 based on the informa-
tion requested in Table 1. The configuration defines the
number of series cells, the nominal battery pack capac-
ity, the self-discharge rate, and the LED display mode.
A module development kit is also available for the
bq2110. The bq2110B-KT or bq2110LB-KT includes one
configured module and the following:
1)
An interface board that allows connection to the se-
rial port of an AT-compatible computer.
2)
Menu-driven software with the bq2110 to display
charge/discharge activity and to allow user inter-
face to the bq2010 from any standard DOS PC.
3)
Source code for the TSR.
Pin Descriptions
P1
DQ/Serial communication port
P2
BAT+/Battery positive/pack positive
P3
No connect
P4
EMPTY/Empty indicator output
P5
GND/Ground
P6
PACK-/Pack negative
P7
BAT-/Battery negative
1
NiCd or NiMH Gas Gauge Module
bq2110
5/99 B
2
bq2110
Customer Name: ___________________________________________________________________________
Contact: _________________________________________
Phone: ______________________________
Address: _________________________________________________________________________________
_________________________________________________________________________________
Sales Contact: ____________________________________
Phone: ______________________________
Number of series battery cells (4-12)
________________________________________
Battery type (NiCd or NiMH)
________________________________________
Battery pack capacity (mAh)
________________________________________
Discharge rate into load (3.0A max)
Min.
Avg.
Max.
Charge rate (3.0A max)
________________________________________
Display mode (absolute or relative)
________________________________________
LEDs and switch (Y/N)
________________________________________
FAE approval: _____________________________________
Date:________________________________
Table 1. bq2110 Module Configuration
Charger
Load
P7
P6
bq2110
Cells
Battery Pack
PACK+
PACK-
P2
FG-969
Figure 1. Module Connection Diagram
3
bq2110
bq2110 Schematic
Note:
Schematic shows components which may not be placed on the
board, depending upon the configuration.
4
bq2110
bq2110 Board
5
bq2110
Absolute Maximum Ratings
Symbol
Parameter
Minimum
Maximum
Unit
Conditions
V
CC
Relative to V
SS
-0.3
+7.0
V
bq2010
All other pins
Relative to V
SS
-0.3
+7.0
V
bq2010
P
SR
Continuous sense resistor
power dissipation
-
3
W
Thru-hole sense resistor
-
1
W
Surface mount sense resistors
I
CHG
Continuous charge/
discharge current
-
3.0
A
T
OPR
Operating temperature
0
+70
°C
Commercial
T
STR
Storage temperature
-40
+85
°C
Note:
Permanent device damage may occur if Absolute Maximum Ratings are exceeded. Functional operation
should be limited to the Recommended DC Operating Conditions detailed in this data sheet. Exposure to con-
ditions beyond the operational limits for extended periods of time may affect device reliability.
DC Electrical Characteristics
(TA = TOPR)
Symbol
Parameter
Minimum
Typical
Maximum
Unit
Conditions/Notes
NumCell
Number of series cells in bat-
tery pack
4
-
12
-
BAT+
Positive terminal of pack
GND
NumCell
1.2V
*
NumCell
1.8V
*
V
BAT-
Negative terminal of pack
GND - 0.3
-
GND+2.0
V
I
CC
Supply current at BAT+ ter-
minal (no external loads)
-
200
300
µA
R
DQ
Internal pull-down
500k
-
-
Ω
1
I
OL
Open-drain sink current DQ,
EMPTY
-
-
5.0
mA
1
V
OL
Open-drain output low, DQ,
EMPTY
-
-
0.5
V
1
I
OL
< 5mA
V
IHDQ
DQ input high
2.5
-
-
V
1
V
ILDQ
DQ input low
-
-
0.8
V
1
V
OS
Voltage offset
-
-
150
µV
1
Note:
1. Characterized on PCB, IC 100% tested.
6
bq2110
DC Voltage Thresholds
(TA = TOPR)
Symbol
Parameter
Minimum
Typical
Maximum
Unit
Notes
V
EDVF
Final empty warning
0.93
0.95
0.97
V
BAT+/NumCell
1
V
EDV1
First empty warning
1.03
1.05
1.07
V
BAT+/NumCell
1
V
MCV
Maximum single-cell voltage
2.20
2.25
2.30
V
BAT+/NumCell
1
V
SRO
Sense resistor range
-300
-
+2000
mV
V
SR
+ V
OS2
V
SRQ
Valid charge
375
-
-
µV
V
SR
+ V
OS 2, 3
V
SRD
Valid discharge
-
-
-300
µV
V
SR
+ V
OS 2, 3
Notes:
1.
At SB input of bq2010
2.
At SR input of bq2010.
3.
Default value; value set in DMF register.
7
bq2110
Ordering Information
Notes:
1.
Requires configuration sheet (see Table 1)
2.
Example production part number: bq2110LB-001
Customer Code:
Blank: = Sample or Pre-production
1
KT = Evaluation system
XXX = Customer-specific; assigned by Unitrode
2
Package Option:
B = Board-level product
LED Option:
L = LEDs plus switch
Device:
NiCd or NiMH Gas Gauge Module
bq2110
B —
Change No.
Page No.
Description
1
2
Updated Table 1 to include 3.0A limit
1
5
Added 3.0A maximum continuous charge/discharge current specification
Note:
Change 1 = May 1999 B changes from July 1996.
Data Sheet Revision History
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©
1999, Texas Instruments Incorporated