MAX17055

Part: MAX17055 from Maxim Integrated

Type: Fuel Gauge

Description: The MAX17055 is a low 7μA operating current fuel gauge that implements the ModelGauge m5 EZ algorithm, providing accurate state of charge and remaining capacity for lithium batteries with precision current, voltage, and temperature measurements.

Operating Conditions:

• Supply voltage: 2.3–4.9 V
• Operating temperature: -40 to +85 °C
• I2C clock frequency: Up to 400 kHz

Absolute Maximum Ratings:

• Max supply voltage (BATT to CSP): +6 V
• Max ALRT voltage: +17 V
• Max CSN voltage: +2 V

Key Specs:

• Hibernate supply current (I_DD1): 7 μA (typ, T_A ≤ +50°C)
• Active supply current (I_DD2): 18 μA (typ, T_A ≤ +50°C)
• BATT measurement error: ±7.5 mV (T_A = +25°C)
• Current measurement offset error: ±1.5 μV (typ)
• Current measurement range (I_FS): ±51.2 mV
• Internal temperature measurement error: ±1 °C (typ)
• SCL clock frequency (f_SCL): 0–400 kHz
• Sense resistor range: 1mΩ to 1000mΩ

Features:

• ModelGauge m5 EZ algorithm (no characterization required, robust against battery variation, eliminates error near empty voltage, eliminates coulomb counter drift, current/temperature/age compensated)
• Low 7μA operating current
• Wide sense resistor range (1mΩ to 1000mΩ)
• Supports Li+ and variants including LiFePO4
• ±1°C internal temperature or external thermistor measurement
• Dynamic power estimates power capability during discharge
• Time-to-Empty and Time-to-Full estimation
• Precision measurement system (no calibration required)
• Alert indicator for voltage, SOC, temperature, current and 1% SOC change

Applications:

• Wearables, Smartwatches
• Smartphones
• Tablets, 2-in-1 Laptops
• Bluetooth Headsets
• Health and Fitness Monitors
• Digital Still, Video, and Action Cameras
• Medical Devices
• Handheld Computers and Terminals
• Wireless Speakers
• Home and Building Automation, Sensors
• Portable Game Players
• Toys

Package:

• WLP (9-pin, 1.4mm x 1.5mm)
• TDFN (10-pin, 2mm x 2.5mm)

• ModelGauge m5 EZ
  • No Characterization Required for EZ Performance
  • Robust Against Battery Variation
  • Eliminates Error Near Empty Voltage
  • Eliminates Coulomb Counter Drift
  • Current, Temperature, and Age Compensated
  • Does Not Require Empty, Full, or Idle States
• Low 7μA Operating Current
• Wide Sense Resistor Range
  • 1mΩ to 1000mΩ
  • PCB Metal Sensing + Temperature Compensation
• Supports Li+ and Variants Including LiFePO4
• ±1°C Internal Temperature or Thermistor
• Dynamic Power Estimates Power Capability During Discharge
• Time-to-Empty and Time-to-Full Estimation
  • Constant Power or Constant Current
• Predicts Remaining Capacity Under Theoretical Load
• Precision Measurement System
  • No Calibration Required
• Alert Indicator for Voltage, SOC, Temperature, Current and 1% SOC Change

• Wearables, Smartwatches
• Smartphones
• Tablets, 2-in-1 Laptops
• Bluetooth Headsets
• Health and Fitness Monitors
• Digital Still, Video, and Action Cameras
• Medical Devices
• Handheld Computers and Terminals
• Wireless Speakers
• Home and Building Automation, Sensors
• Portable Game Players
• Toys

ModelGauge is a trademark of Maxim Integrated Products, Inc. Ordering Information appears at end of data sheet.

(V_BATT = 2.3V to 4.9V, T_A = -40^°C to 85^°C, typical values are T_A = +25^°C, Limits are 100% tested at T_A = +25^°C. Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Specifications marked GBD are guaranteed by design and not production tested.)

Figure 1 shows two application circuits. One where the MAX17055 is located in a system that has a removable battery pack and the other where the MAX17055 is located in a system with a captive battery. In both cases, the IC is mounted outside of the protector circuit to allow communication to the pack even when the protection FETs are disabled. Take care to avoid exceeding the maximum operating voltage on any pin under fault conditions. In the removable battery system, temperature readings are made using an external thermistor divider network. In the captive pack system, temperature measurements are made internal to the IC saving the cost and size of two components. System current is measured using an external sense resistor connected between the CSP and CSN pins. System voltage measurements are made between the BATT and CSP pins. Keep the BATT and REG bypass capacitor loop areas as small as possible by connecting them directly to CSP. Note that when using the TDFN package option connect the exposed pad (EP) directly to CSP.

Figure 1. Typical Application Schematics