Analog Devices has introduced the LTC3337, a nanopower primary (non-rechargeable) cell State-of-Health (SoH) monitor with precision coulomb counter, designed to be placed in series with a primary battery with minimal associated series voltage drop. The patented infinite dynamic range coulomb counter tallies all accumulated battery discharge and stores it in an internal register accessible via an I2C interface. Quiescent current consumption is only 100 nA, increasing battery run time.
The LTC3337 integrates additional SoH variable monitoring which measures and reports via I2C: battery voltage, battery impedance, and temperature. To accommodate a wide range of primary battery inputs, the peak input current limit is pin selectable from 5 mA to 100 mA. This enables the IC to present the battery with a load profile which allows it to deliver its maximum capacity, independent of the actual load. This is “battery friendly” and prolongs the lifetime of the cell. The LTC3337 is ideal for primary cell applications that require only occasional power such as applications in remote locations, electronic door locks, or glass break detectors. The device may also be used in rechargeable battery cell applications.