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REV: 042505
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here:
www.maxim-ic.com/errata
.
GENERAL DESCRIPTION
The DS2782 measures voltage, temperature and
current, and estimates available capacity for
rechargeable lithium ion and lithium-ion polymer
batteries. Cell characteristics and application
parameters used in the calculations are stored in on-
chip EEPROM. The available capacity registers
report a conservative estimate of the amount of
charge that can be removed given the current
temperature, discharge rate, stored charge and
application parameters. Capacity estimation reported
in mAh remaining and percentage of full.
APPLICATIONS
Digital Still Cameras
Sub-Notebook Computers
Handheld PC Data Terminals
3G Multimedia Wireless Handsets
TYPICAL OPERATING CIRCUIT
FEATURES
Precision Voltage, Temperature, and Current
Measurement System
Accurate Stable Internal Time Base
Absolute and Relative Capacity Estimated from
Coulomb Count, Discharge Rate, Temperature
and Battery Cell Characteristics
Accurate Warning of Low Battery Conditions
Automatic Backup of Coulomb Count and Age
Estimation to Nonvolatile (NV) EEPROM
Gain and Tempco Calibration Allows the Use of
Low-Cost Sense Resistors
24-Byte User EEPROM or 16-Byte User
EEPROM and Unique 64-bit ID
Industry 2-Wire Interface with Programmable
Slave Address
Tiny 8-Pin TSSOP Package Embeds Easily in
Battery Packs Using Thin Prismatic Cells
PIN CONFIGURATION
SDA 5
SNS 7
4
VDD
2
VSS
RSNS
Pack+
Pack-
SDA
Protection
Circuit
DS2782
SCL 6
150
1 Cell
Li-Ion
Battery
0.1uF
1
NC
3
VIN
500
1K
PIO 8
TSSOP-8
5.6V
SCL
150
5.6V
ORDERING INFORMATION
PART MARKING
PACKAGE
INFORMATION
DS2782E+ 2782+
Lead-Free
TSSOP
DS2782E+T&R 2782+
DS2782E+,
Tape-and-Reel
Note: To order devices with the unique 64-bit ID option, contact Maxim/Dallas Semiconductor sales.
DS2782
Stand-Alone Fuel Gauge IC
www.maxim-ic.com
TOP VIEW
1
2
3
4
5
6
7
8
NC
VSS
VIN
VDD
PIO
SNS
SCL
SDA
TSSOP-8
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ABSOLUTE MAXIMUM RATINGS
Voltage Range on Any Pin Relative to V
SS
-0.3V to +6.0V
Voltage on V
IN
Relative to V
SS
-0.3V to VDD+0.3
Operating Temperature Range
-40C to +85C
Storage Temperature Range
-55C to +125C
Soldering Temperature
See IPC/JEDEC J-STD-020A Specification
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only,
and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is
not implied. Exposure to the absolute maximum rating conditions for extended periods may affect device.
RECOMMENDED DC OPERATING CHARACTERISTICS
(V
DD
= 2.5V to 5.5V; T
A
= -20C to +70C, unless otherwise noted. Typical values are at T
A
= +25C.)
PARAMETER SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
V
DD
(Note
1)
+2.5
+5.5
V
SDA, SCL, PIO Voltage
Range
(Note
1)
-0.3
+5.5 V
DC ELECTRICAL CHARACTERISTICS
(V
DD
= 2.5V to 5.5V; T
A
= -20C to +70C, unless otherwise noted. Typical values are at T
A
= +25C.)
PARAMETER SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2.5V V
DD
4.2V
65
95
ACTIVE Current
I
ACTIVE
105
A
SLEEP Mode Current
I
SLEEP
2.5V
V
DD
4.2V
1
3
A
Input Logic High:
SDA, SCL, PIO
V
IH
(Note
1)
1.5
V
Input Logic Low:
SDA, SCL, PIO
V
IL
(Note
1)
0.6
V
Output Logic Low: SDA, PIO
V
OL
I
OL
= 4mA (Note 1)
0.4
V
Pulldown Current:
SDA, SCL, PIO
I
PD
V
SDA
, V
SCL
, V
PIO
=
0.4V
0.2
A
V
IN
Input Resistance
R
IN
15
M
W
Bus Low to Sleep time
t
SLEEP
SDA, SCL < V
IL
(Note 2)
2.2 s
Undervoltage SLEEP
Threshold
V
SLEEP
(Note
1)
2.40 2.45 2.50
V
ELECTRICAL CHARACTERISTICS: TEMPERATURE, VOLTAGE, CURRENT
(V
CC
= 2.5V to 5.5V; T
A
= -20C to +70C, unless otherwise noted. Typical values are at T
A
= +25C.)
PARAMETER SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Temperature Resolution
T
LSB
0.125
C
Temperature Error
T
ERR
3 C
Voltage Resolution
V
LSB
4.88
mV
Voltage Full-Scale
V
FS
0
4.992 V
Voltage Error
V
ERR
50 mV
Current Resolution
I
LSB
1.56
V
Current Full-Scale
I
FS
51.2 mV
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PARAMETER SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Current Gain Error
I
GERR
(Note
3)
1
% Full-
Scale
Current Offset Error
I
OERR
0C T
A
+70C,
2.5V V
DD
4.2V
(Note 5)
- 7.82
+ 12.5
V
Accumulated Current Offset
q
OERR
0C T
A
+70C,
2.5V V
DD
4.2V
V
SNS
= V
SS
, (Notes 4, 5)
- 188
+ 0
Vhr/
day
V
DD
= 3.8V, T
A
= +25C
1
0C T
A
+70C,
2.5V VDD 4.2V
2
Timebase Error
t
ERR
3
%
ELECTRICAL CHARACTERISTICS: 2-WIRE INTERFACE
(2.5V
V
DD
5.5V, T
A
= -20
C to +70C.)
PARAMETER SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SCL Clock Frequency
fSCL
(Note 6)
0
400
KHz
Bus Free Time Between a STOP
and START Condition
tBUF
1.3
s
Hold Time (Repeated)
START Condition
tHD:STA
(Note 7)
0.6
s
Low Period of SCL Clock
tLOW
1.3
s
High Period of SCL Clock
tHIGH
0.6
s
Setup Time for a Repeated
START Condition
tSU:STA
0.6
s
Data Hold Time
tHD:DAT
(Note 8, 9)
0
0.9
s
Data Setup Time
tSU:DAT
(Note 8)
100
ns
Rise Time of Both SDA and
SCL Signals
tR
20 + 0.1C
B
300 ns
Fall Time of Both SDA and
SCL Signals
tF
20 + 0.1C
B
300 ns
Setup Time for STOP
Condition
tSU:STO
0.6
s
Spike Pulse Widths Suppressed
by Input Filter
tSP
(Note 10)
0
50
ns
Capacitive Load for Each Bus
Line
CB
(Note 11)
400
pF
SCL, SDA Input Capacitance
C
BIN
60
pF
EEPROM RELIABILITY SPECIFICATION
(V
CC
= 2.5V to 5.5V; T
A
= -20C to +70C, unless otherwise noted. Typical values are at T
A
= +25C.)
PARAMETER SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
EEPROM Copy Time
t
EEC
10 ms
EEPROM Copy Endurance
N
EEC
T
A
= +50C
50,000
cycles
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Note 1: All voltages are referenced to V
SS
.
Note 2: To properly enter sleep mode the application should hold the bus low for longer than the maximum t
SLEEP
.
Note 3: Factory calibrated accuracy. Higher accuracy can be achieved by in-system calibration by the user.
Note 4: Accumulation bias register set to 00h.
Note 5: Parameters guaranteed by design.
Note 6: Timing must be fast enough to prevent the DS2782 from entering sleep mode due to bus low for period >
t
SLEEP
.
Note 7: f
SCL
must meet the minimum clock low time plus the rise/fall times.
Note 8: The maximum t
HD:DAT
has only to be met if the device does not stretch the LOW period (t
LOW
) of the SCL
signal.
Note 9: This device internally provides a hold time of at least 300 ns for the SDA signal (referred to the VIHmin of
the SCL signal) to bridge the undefined region of the falling edge of SCL.
Note 10: Filters on SDA and SCL suppress noise spikes at the input buffers and delay the sampling instant.
Note 11: C
b
total capacitance of one bus line in pF.
Figure 1. I
2
C Bus Timing Diagram
SDA
SCL
t
F
t
R
t
SU;DAT
t
LOW
S
t
HD;STA
t
HD;DAT
t
F
t
SU;STA
t
HD;STA
t
SU;STO
t
R
t
BUF
t
SP
Sr
P
S
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PIN DESCRIPTION
PIN NAME
FUNCTION
1 NC
Not Connected. Pin not connected internally, float or connect to VSS.
2 VSS
Device Ground. Connect directly to the negative terminal of the battery cell. Connect the
sense resistor between VSS and SNS.
3 VIN
Voltage Sense Input. The voltage of the battery cell is monitored through this input pin.
4 VDD
Power-Supply Input. Connect to the positive terminal of the battery cell through a
decoupling network.
5 SDA
Serial Data Input/Out. 2-Wire data line. Open-drain output driver. Connect this pin to the
DATA terminal of the battery pack. Pin has an internal pull-down (I
PD
) for sensing
disconnection.
6 SCL
Serial Clock Input. 2-Wire clock line. Input only. Connect this pin to the CLOCK terminal
of the battery pack. Pin has an internal pull-down (I
PD
) for sensing disconnection.
7 SNS
Sense Resistor Connection. Connect to the negative terminal of the battery pack.
Connect the sense resistor between VSS and SNS.
8 PIO
Programmable I/O Pin. Can be configured as input or output to monitor or control user-
defined external circuitry. Output driver is open drain. This pin has an weak internal
pulldown (I
PD
).
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