General Description
The AAT2550 is a fully integrated total power solution with two step-down converters plus a single-cell lithiumion / polymer battery charger. The step-down converter input voltage range spans 2.7V to 5.5V, making the AAT2550 ideal for systems powered by single-cell lithium-ion/polymer batteries.
The battery charger is a complete constant current/ constant voltage linear charger. It offers an integrated pass device, reverse blocking protection, high current accuracy and voltage regulation, charge status, and charge termination. The charging current is programmable via external resistor from 100mA to 1A. In addition to these standard features, the device offers over-voltage, overcurrent, and thermal protection.
The two step-down converters are highly integrated, operating at a switching frequency of 1.4MHz, minimizing the size of external components while keeping switching losses low. Each converter has independent input, enable, and feedback pins. The output voltage ranges from 0.6V to VIN. Each converter is capable of delivering up to 600mA of load current.
The AAT2550 is available in a Pb-free, space-saving, thermally-enhanced QFN44-24 package and is rated over the -40°C to +85°C temperature range.
Features
• Two Step-Down Converters:
? 600mA Output Current per Converter
? VIN Range: 2.7V to 5.5V
? 1.4MHz Switching Frequency
? Low RDS(ON) 0.4Ω Integrated Power Switches
? Internal Soft Start
? 27μA Quiescent Current per Converter
• Highly Integrated Battery Charger:
? Programmable Charging Current from 100mA to 1A
? Pass Device
? Reverse Blocking Diodes
? Current Sensing Resistor
? Digital Thermal Regulation
• Short-Circuit, Over-Temperature, and Current Limit
Protection
• QFN44-24 Package
• -40°C to +85°C Temperature Range
Applications
• Cellular Telephones
• Digital Cameras
• Handheld Instruments
• MP3, Portable Music, and Portable Media Players
• PDAs and Handheld Computers
Click to view :
AAT2550.pdf
