LTC4080EMSE Datasheet - Linear Technology

DESCRIPTION
The LTC4080 is a complete constant-current/constant-voltage linear battery charger for a single-cell 4.2V lithium-ion battery with an integrated 300mA synchronous buck converter. The small packages and low external component count make the LTC4080 especially suitable for portable applications. Furthermore, LTC4080 is specifically designed to work within USB power specifi cations.

FEATURES
■ Complete Linear Battery Charger with Integrated
   Buck Converter

Battery Charger:
■ Constant-Current/Constant-Voltage Operation
   with Thermal Feedback to Maximize Charge Rate
   Without Risk of Overheating
■ Internal 4.5 Hour Safety Timer for Termination
■ Charge Current Programmable Up to 500mA with
   5% Accuracy
■ C/10 Charge Current Detection Output
■ 5μA Supply Current in Shutdown Mode

Switching Regulator:
■ High Effi ciency Synchronous Buck Converter
■ 300mA Output Current
■ 2.7V to 4.5V Input Range (Powered from BAT Pin)
■ 0.8V to VBAT Output Range
■ MODE Pin Selects Fixed (2.25MHz) Constant-Frequency
   PWM Mode or Low ICC (23μA) Burst Mode®
   Operation
■ 2μA BAT Current in Shutdown Mode

APPLICATIONS
■ Wireless Headsets
■ Bluetooth Applications
■ Portable MP3 Players
■ Multifunction Wristwatches