Suited for multicell applications, 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 allows for 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 gas gauge. 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 LTC2943 supports operating temperature ranges from 0°C to 70°C and -40°C to 85°C, respectively. Priced at $2.35 each in 1,000 piece quantities, the LTC2943 is available today in a small RoHS compliant, 8-pin 3mm x 3mm DFN package.