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Low-Cost, 2-Wire Battery Monitor with Ratiometric A/D Inputs

2-Wire Fuel Gauge Measures Battery Current and Voltage and Includes Ratiometric Voltage Inputs that Can Be Used to Sample Thermistor, Pack ID, or Another Voltage Source

Product Details

Key Features

Parametric specs for Battery Fuel Gauges, Protectors, and Monitors
Functions Fuel Gauge
Battery Type 1 Cell Li-Ion
3-Cell NiMH
Interface 2-Wire
Parameters Measured Current
Voltage
End Equipment Host
VSUPPLY (V) (min) 2.5
VSUPPLY (V) (max) 5.5
Package/Pins TDFN/10
Oper. Temp. (°C) -40 to +85
Budgetary
Price (See Notes)
2.59
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Simplified Block Diagram

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Parameters

Parametric specs for Battery Fuel Gauges, Protectors, and Monitors
Functions Fuel Gauge
Battery Type 1 Cell Li-Ion
3-Cell NiMH
Interface 2-Wire
Parameters Measured Current
Voltage
End Equipment Host
VSUPPLY (V) (min) 2.5
VSUPPLY (V) (max) 5.5
Package/Pins TDFN/10
Oper. Temp. (°C) -40 to +85
Budgetary
Price (See Notes)
2.59

Key Features

  • 14-Bit Bidirectional Current Measurement
    • 6.25µV LSB, ±51.2mV Dynamic Range
    • 416.7µA LSB, ±3.4A Range (RSNS = 15mΩ)
  • Current Accumulation Register Resolution
    • 6.25µVhr LSB, 409.6mVh Range
    • 417µAhr LSB, 27.31Ah Range
  • 11-Bit Battery Voltage Measurement
    • 2.44mV LSB, 0V to 4.997V Input Range
    • ±10mV Accuracy at 3.6V Input
  • Two 11-Bit Aux Input Voltage Measurements
    • Ratiometric Inputs Eliminate Supply Error
    • VOUT drives Dividers, Reduces Power
    • ±8 LSB Accuracy
  • Low Power Consumption:
    • Active Current: 70µA typical, 100µA max
    • Sleep Current: 1µA typical, 3µA max

Applications/Uses

  • 2.5G/3G Wireless Handsets
  • Digital Still and Video Cameras
  • Handheld Computers and Terminals
  • PDA/Smartphones

Description

The DS2746 remains in production, however, for new projects, we recommend ModelGauge m5 MAX17055 fuel gauge.

The DS2746 provides system-side battery capacity monitoring in cost-sensitive applications. Voltage, bidirectional current, and accumulated current measurement data is provided to the host processor over a 2-wire interface. Offset bias and offset blanking features greatly enhance the accuracy of the coulomb counter. In addition, the DS2746 has two auxiliary A/D inputs to sample the pack identification resistor, thermistor, or other voltage source. The results are reported as a ratiometric fraction of the supply voltage eliminating error related to the supply. The DS2746 reduces the total power consumption of the measurement circuit by enabling the resistor dividers, through the VOUT pin, only while measurements are made. When the system is inactive, a low power sleep mode reduces current consumption while maintaining the coulomb count. The tiny 3mm × 3mm TDFN package consumes only 9mm² of PCB space

Simplified Block Diagram

DS2746 provides system-side battery capacity monitoring in cost-sensitive applications | Typical Operating Circuit DS2746 provides system-side battery capacity monitoring in cost-sensitive applications | Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .