Multicell battery monitor offers high accuracy

January 30, 2017 // By Christoph Hammerschmidt
With electric vehicles gaining traction in the market, car designers can choose from an increasing range of battery monitoring solutions. The latest entry is Linear Technology’s LTC2944, a high voltage battery monitor SoC that measures charge, voltage, current and temperature to 1% accuracy, the essential parameters required to accurately assess battery state of charge.

The LTC2944 multicell battery monitor 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. Applications including electric vehicles, ebikes/motorcycles/scooters, wheelchairs, golf carts and battery backup systems. The battery current is measured by monitoring the voltage across an external, high side sense resistor and integrating this information to infer charge. A bidirectional analog 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 I 2C/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.

Offered in commercial and industrial versions, the LTC2944 supports operating temperature ranges from 0°C to 70°C and –40°C to 85°C, respectively. It is available in a small RoHS-compliant, 8-pin 3mm x 3mm DFN package. Pricing starts at $2.85 each in 1,000-piece quantities.

For more information visit www.linear.com/product/LTC2944