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MAX17261
5.1μA Multi-Cell Fuel Gauge
with ModelGauge m5 EZ
General Description
Benefits and Features
The MAX17261 is an ultra-low power fuel gauge IC which
implements the Maxim ModelGauge™ m5 algorithm. The
IC monitors a multiple-series cell battery pack with an ex-
ternal resistor divider.
● ModelGauge m5 EZ
• No Characterization Required for EZ Performance
• Robust Against Battery Variation
• Eliminates Error Near Empty Voltage
• Eliminates Coulomb Counter Drift
• Compensates for Age, Current, and Temperature
• Does Not Require Empty, Full, or Idle States
The ModelGauge m5 EZ algorithm makes fuel gauge im-
plementation easy by eliminating battery characterization
requirements and simplifying host software interac-
tion. The algorithm provides tolerance against battery di-
versity for most lithium batteries and applications.
● Low 5.1μA Operating Current
● Monitors Multiple-Cell Battery Pack
● Wide Sense Resistor Range: 1mΩ to 1000mΩ
● PCB Metal Sensing + Temperature Compensation
The algorithm combines the short-term accuracy and lin-
earity of a coulomb counter with the long-term stability of
a voltage-based fuel gauge, along with temperature com-
pensation to provide industry-leading fuel gauge accura-
cy. The IC automatically compensates for cell-aging, tem-
perature, discharge rate, and provides accurate state-of-
charge (SOC) in percentage (%) and remaining capacity
in milliampere-hours (mAh) over a wide range of operat-
ing conditions. As the battery approaches the critical re-
gion near empty, the algorithm invokes a special correc-
tion mechanism that eliminates any error. The IC provides
accurate estimation of time-to-empty and time-to-full and
provides three methods for reporting the age of the bat-
tery: reduction in capacity, increase in battery resistance,
and cycle odometer.
● Supports Li+ and Variants Including LiFePO
● Thermistor or ±1°C Internal Temperature
4
● Dynamic Power Estimates Power Capability During
Discharge
● Time-to-Empty and Time-to-Full Estimation
● Predicts Remaining Capacity Under Theoretical Load
● No Calibration Required
● Alert Indicator for Voltage, SOC, Temperature,
Current and 1% SOC Change
Ordering Information appears at end of data sheet.
Simple Fuel Gauge Circuit Diagram
The IC provides precision measurements of current, volt-
age, and temperature. The temperature of the battery
pack is measured using an internal temperature sensor or
SYSPWR
3~5V
BATT
REG
2
external thermistor. A 2-wire I C interface provides access
0.1µF
to data and control registers. The IC is available in a tiny
lead-free 0.4mm pitch, 1.5mm x 1.5mm, 9-pin WLP pack-
age and 3mm x 3mm, 14-pin TDFN package.
REG
0.47µF
CELLX
MAX17261
ALRT
Applications
SDA
SCL
PROTECTION
CIRCUIT
● Tablets, 2-in-1 Laptops
● Digital Still, Video, and Action Cameras
● Medical Devices
TH
CSPL (TDFN)
EP (TDFN)
RSENSE
GND
CSN
● Handheld Computers and Terminals
● Financial Terminals
● Mobile Printers
● Augmented/Virtual Reality Devices
● Robots
10kΩ
NTC
SYSGND
● E-Bikes
● Battery Backups
● Wireless Speakers
ModelGauge is a trademark of Maxim Integrated Products, Inc.
19-100318; Rev 0; 5/18