This document introduces the LTC2941/LTC2942 coulomb counters, which are used for accurate lithium battery gauging. The counters use continuous-time analog integrators, resulting in minimal offset and gain errors, and better overall charge accuracy. The bidirectional analog integrator accommodates both battery charge and discharge, and a programmable prescaler allows for a wide range of battery capacities. The LTC2942 also incorporates a 14-bit ∆∑ ADC to measure battery voltage and die temperature. The LTC2941-1 and LTC2942-1 also integrate a 50mΩ sense resistor to provide up to ±1A measurement range. Charge, voltage* and temperature* are all communicated to the host system over an I2C/SMBus compatible interface.
