Battery monitor measures charge to 1% accuracy

The LTC2944 is a 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).

The LTC2944 is suitable for multicell applications, including 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 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 programme 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 to 70°C and -40 to 85°C, respectively. The LTC2944 is available in a small RoHS-compliant, 8-pin 3x3mm DFN package.

Key features:

• Measures accumulated battery charge and discharge
• 3.6-60V operating range for multicell applications
• 14-Bit ADC measures voltage, current and temperature
• 1% charge, voltage and current accuracy
• 50mV sense voltage range
• High side sense
• I²C/SMBus interface
• Configurable alert output/charge complete input
• Quiescent current less than 150μA
• Small 8-pin 3x3mm DFN package