LTC2944I

Part: LTC2944 — Linear Technology

Type: Battery Gas Gauge

Description: 3.6 V to 60 V multicell battery gas gauge with internal 14-bit ADC measuring voltage, current, and temperature alongside a precision coulomb counter.

Operating Conditions:

• Supply voltage: 3.6 to 60 V
• Operating temperature: 0 to 70 °C (suffix-dependent — see Order Information for grade-specific ranges)
• Sense voltage differential input range: ±50 mV

Absolute Maximum Ratings:

• Max junction/storage temperature: -65 to 150 °C (storage temperature range)

Key Specs:

• Supply current (Gas gauge on, ADC sleep): 80 μA typ, 150 μA max (over full operating temperature range)
• Supply current (Gas gauge on, ADC on): 850 μA typ, 950 μA max (over full operating temperature range)
• Supply current (Shutdown): 15 μA typ, 30 μA max (over full operating temperature range)
• Total charge error: ±1% max (10 mV ≤ |VSENSE| ≤ 50 mV DC at 25 °C)
• Voltage measurement resolution: 14 bits (4.32 mV quantization step, 70.8 V full-scale)
• Current measurement resolution: 12 bits (31.25 μV quantization step, ±64 mV full-scale)
• Temperature measurement resolution: 11 bits (0.25 K quantization step, 510 K full-scale)
• SCL maximum clock frequency: 400 kHz min, 900 kHz typ

Features:

• Measures accumulated battery charge and discharge
• High-side current sensing with ±50 mV differential sense range
• Internal 14-bit No Latency ΔΣ ADC for voltage, current, and temperature measurements
• Programmable high and low alert thresholds for charge, voltage, current, and temperature
• Configurable alert output (ALCC) or charge-complete input
• I2C and SMBus compatible interface

Applications:

• Electric and hybrid electric vehicles
• Power tools
• Electric bicycles, motorcycles, scooters
• High-power portable equipment
• Photovoltaics
• Backup battery systems

Package:

• 8-Lead Plastic DFN (3 mm × 3 mm)

60V Battery Gas Gauge with Temperature, Voltage and Current Measurement

• n Electric and Hybrid Electric Vehicles
• n Power Tools
• n Electric Bicycles, Motorcycles, Scooters
• n High Power Portable Equipment
• n Photo Voltaics
• n Backup Battery Systems

http://www.linear.com/product/LTC2944#orderinfo

For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.

temperature range, otherwise specifications are at T A = 25°C. (Note 2)

%

%

%

%

K

2944fa

(Notes 1, 2)

The LTC ® 2944 measures battery charge state, battery voltage, battery current and its own temperature in portable product applications. The wide input voltage range allows use with multicell batteries up to 60V. A precision coulomb counter integrates current through a sense resistor between the battery's positive terminal and the load or charger. Voltage, current and temperature are measured with an internal 14-bit No Latency ∆ Σ ™ ADC. The measurements are stored in internal registers accessible via the onboard I 2 C/SMBus Interface.

The LTC2944 features programmable high and low thresholds for all four measured quantities. If a programmed threshold is exceeded, the device communicates an alert using either the SMBus alert protocol or by setting a flag in the internal status register. The LTC2944 requires only a single low value sense resistor to set the measured current range.

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