STC3105IQT STMicroelectronics

STC3105 Battery monitor IC with alarm output for gas gauge applications Features 0.5% accuracy battery voltage monitoring Low battery alarm output with programmable thresholds Low power: 60 A in power-saving mode, 2 A max in standby mode TDFN8 3x2 Ideal for implementation of robust gas gauge (Plastic micropackage) systems using open-circuit voltage and coulomb counter methods Small 3x2 mm package Applications Mobile phones, multimedia players, digital Pin connections cameras (top view) Portable medical equipment 1 8 ALM VIN Description 2 7 SDA VCC 3 6 SCL NC The STC3105 battery monitor includes the 4 5 GND CG hardware functions required to implement a low- cost gas gauge for battery monitoring. The STC3105 uses accurate measurements of the battery voltage to estimate a batterys state-of- charge (SOC). It uses a low cost sense resistor to precisely sense the charge or discharge states, detect light-load conditions without ambiguity for voltage measurements, and accurate SOC calculation. The coulomb counter method is used for SOC tracking in high-load conditions. An alarm output signals a low SOC condition, and can also indicate low battery voltage. The alarm threshold levels are programmable. 2 The device is programmable through an I C interface. September 2011 Doc ID 022198 Rev 1 1/23 www.st.com 23Contents STC3105 Contents 1 Block diagram 3 2 Pin assignment . 4 3 Absolute maximum ratings and operating conditions . 5 4 Electrical characteristics . 6 5 Application information 9 6 Functional description 10 6.1 Battery monitoring functions and operating modes . 10 6.2 Battery voltage monitoring 10 6.3 Current sensing 10 6.4 Coulomb counter . 11 6.5 Alarm output . 11 6.6 Battery voltage relaxation timer 12 6.7 Timing diagram in run mode . 13 2 7I C interface . 14 7.1 Read and write operations 14 7.2 Register map 16 8 Package information 18 8.1 TDFN8 package information 19 9 Ordering information . 21 10 Revision history . 22 2/23 Doc ID 022198 Rev 1