680nA I Q Buck-Boost Converter Counts Coulombs LTC3335 VIN = 1.8V to 5.5V VOUT = 1.8V to 5V 0 0 0 1 0 Q IOUT up to 50mA Battery Coulomb Counter Buck-Boost Converter I2C Load Accurate Coulomb Measurement of Battery Usage The LTC®3335 provides a simple and accurate means to monitor battery state of charge while producing a regulated output. This buck-boost converter contains an integrated precision coulomb counter which is easily accessible via an I2C interface. The converter draws only 680nA quiescent current from the battery and offers a number of common fixed output voltage settings to eliminate the need for external resistors. It also features a programmable input current limit and delivers output currents up to 50mA at up to 90% efficiency. Features • 680nA Input Quiescent Current • Input Voltage Range: 1.8V to 5.5V • ±5% Accurate Coulomb Counter Measures Accumulated Battery Discharge • Selectable Outputs: 1.8V, 2.5V, 2.8V, 3V, 3.3V, 3.6V, 4.5V & 5V • Programmable Peak Input Current • Up to 50mA of Output Current at 90% Efficiency Total Unadjusted Coulomb Counter Error 5 3 Info & Free Samples www.linear.com/product/LTC3335 VOUT = 1.8V VOUT = 3.3V VOUT = 5V 4 1-800-4-LINEAR 2 Error (%) 1 0 –1 –2 –3 –4 –5 1.8 2.3 2.8 3.3 3.8 4.3 4.8 Battery Voltage (V) 5.3 , LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.