60V I²C battery monitor measures state-of-charge parameters to 1%

January 31, 2017 // By Graham Prophet
LTC2944 is a multicell battery monitor which makes direct measurements of 3.6V to 60V battery stacks. No level shifting circuitry on the supply and measurement pins is required to interface with multicell voltages, so total current consumption is minimized and measurement accuracy is preserved.

The LTC2944 is a true high voltage battery monitor that measures charge, voltage, current and temperature to 1% accuracy, the essential parameters required to accurately assess battery state of charge (SoC). Linear Technology suggests applications in electric vehicles, ebikes/motorcycles/scooters, wheelchairs, golf carts and battery backup systems.


Battery current is measured by monitoring the voltage across an external, high side sense resistor and integrating this information to infer charge. A bidirectional analogue integrator accommodates either current polarity (battery charge or discharge), and a programmable prescaler supports a wide range of battery capacities. Charge, voltage, current and temperature information are communicated to the host system over an I²C/SMBus-compatible 2-wire interface that is also used to configure the battery monitor. The host can program high and low thresholds for all measured parameters, which if tripped, signal an alert using either the SMBus alert protocol or by setting a register flag.


The LTC2944 is offered in commercial and industrial versions, supporting operating temperature ranges from 0°C to 70°C and –40°C to 85°C, respectively. In a 8-pin 3 x 3 mm DFN package pricing starts at $2.85 (1,000).


Linear Technology; www.linear.com/product/LTC2944


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