DS2760
High-Precision Li+ Battery Monitor
www.maxim-ic.com
FEATURES
§
Li+ safety circuit
- Overvoltage protection
- Overcurrent/short circuit protection
- Undervoltage protection
Zero Volt Battery Recovery Charge
Available in two configurations:
- Internal 25mW sense resistor
- External user-selectable sense resistor
Current measurement
- 12-bit bidirectional measurement
- Internal sense resistor configuration:
0.625mA LSB and ±1.9A dynamic range
- External sense resistor configuration:
15.625mV LSB and ±64mV dynamic range
Current accumulation
- Internal sense resistor: 0.25mAhr LSB
- External sense resistor: 6.25mVhr LSB
Voltage measurement with 4.88mV resolution
Temperature measurement using integrated
sensor with 0.125°C resolution
System power management and control feature
support
32 bytes of lockable EEPROM
16 bytes of general purpose SRAM
Dallas 1-Wire
®
interface with unique 64-bit
device address
Low power consumption:
- Active current: 90mA max
- Sleep current:
2mA max
PIN ASSIGNMENT
CC
PLS
DC
SNS
SNS
SNS
DQ
IS2
1
2
3
2
4
5
6
7
8
16
15
14
13
12
11
10
9
VIN
V
DD
PIO
VSS
VSS
VSS
PS
IS1
1
2
3
SNS
4
A
DQ
IS2
IS1
PS
PLS DC
CC
VIN
SNS
Probe
VSS
Probe
B
C
D
E
F
§
§
§
VDD PIO
VSS
DS2760
16-Pin TSSOP Package
DS2760
Flip-Chip Packaging
Top View
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§
§
§
§
§
§
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PIN DESCRIPTION
- Charge control output
- Discharge control output
DQ - Data input/output
PIO - Programmable I/O pin
PLS - Battery pack positive terminal input
PS
- Power switch sense input
VIN - Voltage sense input
V
DD
- Power supply input (2.5V to 5.5V)
VSS - Device ground
SNS - Sense resistor connection
IS1 - Current sense input
IS2 - Current sense input
SNS Probe - Do not connect
VSS Probe - Do not connect
CC
DC
1-Wire is a registered trademark of Dallas Semiconductor.
1 of 25
010906
DS2760
ORDERING INFORMATION
Part
DS2760AE+
DS2760BE+
DS2760AE+T&R
DS2760 BE+T&R
DS2760AE+025
DS2760BE+025
DS2760AE+025/T&R
DS2760BE+025/T&R
DS2760AX
DS2760BX
DS2760AX-025
DS2760BX-025
DS2760AE
DS2760BE
DS2760AE/T&R
DS2760 BE/T&R
DS2760AE-025
DS2760BE-025
DS2760AE-025/T&R
DS2760BE-025/T&R
Marking
DS2760A
DS2760B
DS2760A
DS2760B
2760A25
2760B25
2760A25
2760B25
DS2760A
DS2760B
DS2760AR
DS2760BR
DS2760A
DS2760B
DS2760A
DS2760B
2760A25
2760B25
2760A25
2760B25
Description
TSSOP, External Sense Resistor, 4.275V Vov, Lead-Free
TSSOP, External Sense Resistor, 4.35V Vov, Lead-Free
DS2760AE+ on Tape & Reel, Lead-Free
DS2760BE+ on Tape & Reel, Lead-Free
TSSOP, 25mW Sense Resistor, 4.275V Vov, Lead-Free
TSSOP, 25mW Sense Resistor, 4.35V Vov, Lead-Free
DS2760AE+025 in Tape & Reel, Lead-Free
DS2760BE+025 in Tape & Reel, Lead-Free
Flipchip, External Sense Resistor, Tape & Reel, 4.275V Vov
Flipchip, External Sense Resistor, Tape & Reel, 4.35V Vov
Flipchip, 25mW Sense Resistor, Tape & Reel, 4.275V Vov
Flipchip, 25mW Sense Resistor, Tape & Reel, 4.35V Vov
TSSOP, External Sense Resistor, 4.275V Vov
TSSOP, External Sense Resistor, 4.35V Vov
DS2760AE on Tape & Reel
DS2760BE on Tape & Reel
TSSOP, 25mW Sense Resistor, 4.275V Vov
TSSOP, 25mW Sense Resistor, 4.35V Vov
DS2760AE-025 in Tape & Reel
DS2760BE-025 in Tape & Reel
DESCRIPTION
The DS2760 High-Precision Li+ Battery Monitor is a data acquisition, information storage, and safety
protection device tailored for cost-sensitive battery pack applications. This low-power device integrates
precise temperature, voltage, and current measurement, nonvolatile data storage, and Li+ protection into
the small footprint of either a TSSOP package or flip chip. The DS2760 is a key component in
applications including remaining capacity estimation, safety monitoring, and battery-specific data storage.
Via its 1-Wire interface, the DS2760 gives the host system read/write access to status and control
registers, instrumentation registers, and general purpose data storage. Each device has a unique factory-
programmed 64-bit net address which allows it to be individually addressed by the host system,
supporting multi-battery operation.
The DS2760 is capable of performing temperature, voltage and current measurement to a resolution
sufficient to support process monitoring applications such as battery charge control, remaining capacity
estimation, and safety monitoring. Temperature is measured using an on-chip sensor, eliminating the need
for a separate thermistor. Bidirectional current measurement and accumulation are accomplished using
either an internal 25mW sense resistor or an external device. The DS2760 also features a programmable
I/O pin that allows the host system to sense and control other electronics in the pack, including switches,
vibration motors, speakers and LEDs.
Three types of memory are provided on the DS2760 for battery information storage: EEPROM, lockable
EEPROM and SRAM. EEPROM memory saves important battery data in true nonvolatile memory that
is unaffected by severe battery depletion, accidental shorts or ESD events. Lockable EEPROM becomes
ROM when locked to provide additional security for unchanging battery data. SRAM provides
inexpensive storage for temporary data.
2
DS2760
BLOCK DIAGRAM
Figure 1
DQ
1-WIRE
INTERFACE
AND
ADDRESS
THERMAL
SENSE
VIN
IS1
IS2
PLS
PS
MUX
VOLTAGE
REFERENCE
ADC
REGISTERS AND
USER MEMORY
LOCKABLE EEPROM
SRAM
TEMPERATURE
VOLTAGE
CURRENT
ACCUM. CURRENT
STATUS / CONTROL
LI+ PROTECTION
TIMEBASE
PIO
CC
DC
internal sense resistor configuration only
SNS
25mW
chip ground
VSS
+
-
IS2
IS1
3
DS2760
DETAILED PIN DESCRIPTION
Table 1
SYMBOL
CC
DC
TSSOP*
1
3
7
FLIP
CHIP*
C1
B2
B4
DESCRIPTION
Charge Protection Control Output.
Controls an external p-channel
high-side charge protection FET.
Discharge Protection Control Output.
Controls an external p-channel
high-side discharge protection FET.
Data Input/Out.
1-Wire data line. Open-drain output driver. Connect
this pin to the DATA terminal of the battery pack. Pin has an internal
1mA pull-down for sensing disconnection.
Programmable I/O Pin.
Used to control and monitor user-defined
external circuitry. Open drain to VSS.
Battery Pack Positive Terminal Input.
The device monitors the state of
the battery pack’s positive terminal through this pin in order to detect
events such as the attachment of a charger or the removal of a short
circuit. Additionally, a charge path to recover a deeply depleted cell is
provided from PLS to VDD.
Power Switch Sense Input.
The device wakes up from Sleep Mode
when it senses the closure of a switch to VSS on this pin. Pin has an
internal 1mA pull-up to V
DD
.
Voltage Sense Input.
The voltage of the Li+ cell is monitored via this
input pin. This pin has a weak pullup to V
DD
.
Power Supply Input.
Connect to the positive terminal of the Li+ cell
through a decoupling network.
Device Ground.
Connect directly to the negative terminal of the Li+ cell.
For the external sense resistor configuration, connect the sense resistor
between VSS and SNS.
Sense Resistor Connection.
Connect to the negative terminal of the
battery pack. In the internal sense resistor configuration, the sense resistor
is connected between VSS and SNS.
Current Sense Input.
This pin is internally connected to VSS through a
4.7kW resistor. Connect a 0.1mF capacitor between IS1 and IS2 to
complete a low-pass input filter.
Current Sense Input.
This pin is internally connected to SNS through a
4.7kW resistor.
Do Not Connect.
Do Not Connect.
DQ
PIO
PLS
14
2
E2
B1
PS
10
E4
VIN
V
DD
VSS
SNS
16
15
11,12,13
D1
E1
F3
4,5,6
A3
IS1
9
D4
IS2
SNS
Probe
VSS
Probe
8
N/A
N/A
C4
C2
D2
* Mechanical drawing for the 16-pin TSSOP and DS2760 flip-chip package can be found at:
http://pdfserv.maxim-ic.com/arpdf/Packages/16tssop.pdf
http://pdfserv.maxim-ic.com/arpdf/Packages/chips/2760x.pdf
4
DS2760
APPLICATION EXAMPLE
Figure 2
102
PACK+
BAT+
1k
W
1k
W
DS2760
CC
PLS
DC
SNS
SNS
SNS
DQ
IS2
VIN
V
DD
PIO
VSS
VSS
VSS
PS
IS1
104
1k
W
150
W
150
W
104
150
W
DATA
102
PS
4.7k
W
PACK-
R
SENS
(1)
BAT-
DS2760
SNS
4.7kW
VSS
R
SENSINT
(2)
4.7kW
R
KS
IS2
R
KS
IS1
voltage
sense
1 – R
SENS
is present for external sense resistor configurations only
2 – R
SENSINT
is present for internal sense resistor configurations only
5
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EEWORLD
