Linear Technology Corp. recently introduced the LTC2944 multicell battery monitor, which makes direct measurements of 3.6-to-60-V 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. Well suited for multicell applications (e.g., electric vehicles, ebikes, and battery backup systems), 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).
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). 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 two-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’s features, specs, and benefits:
- Measures accumulated battery charge and discharge
- 3.6-to-60-V Operating range for multicell applications
- 14-Bit ADC Measures voltage, current, and temperature
- 1% Charge, voltage, and current accuracy
- ±50-mV Sense voltage range
- High-side sense
- I²C/SMBus Interface
- Configurable alert output/charge complete input
- Quiescent current less than 150 μA
- Small eight-pin 3 mm × 3 mm DFN package
The LTC2944 is available in a small RoHS-compliant, eight-pin 3 mm × 3 mm DFN package. Pricing starts at $2.85 each in 1,000-piece quantities.
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