General Description
The AAT2554 is a fully integrated 500mA battery charger, a 250mA step-down converter, and a 300mA low dropout (LDO) linear regulator. The input voltage range is 4V to 6.5V for the battery charger and 2.7V to 5.5V for the step-down converter and linear regulator, making it ideal for applications operating with single-cell lithiumion/polymer batteries.
The battery charger is a complete constant current/constant voltage linear charger. It offers an integrated pass device, reverse blocking protection, high accuracy current and voltage regulation, charge status, and charge termination. The charging current is programmable via external resistor from 15mA to 500mA. In addition to these standard features, the device offers over-voltage, current limit, and thermal protection.
The step-down converter is a highly integrated converter operating at a 1.5MHz switching frequency, minimizing the size of external components while keeping switching losses low. It has independent input and enable pins. The output voltage ranges from 0.6V to the input voltage.
The AAT2554 linear regulator is designed for fast transient response and good power supply ripple rejection.
Designed for 300mA of load current, it includes shortcircuit protection and thermal shutdown.
The AAT2554 is available in a Pb-free, thermallyenhanced TDFN34-16 package and is rated over the -40°C to +85°C temperature range.
Features
• Battery Charger:
? Input Voltage Range: 4V to 6.5V
? Programmable Charging Current up to 500mA
? Highly Integrated Battery Charger
• Charging Device
• Reverse Blocking Diode
• Step-Down Converter:
? Input Voltage Range: 2.7V to 5.5V
? Output Voltage Range: 0.6V to VIN
? 250mA Output Current
? Up to 96% Efficiency
? 30μA Quiescent Current
? 1.5MHz Switching Frequency
? 100μs Start-Up Time
• Linear Regulator:
? 300mA Output Current
? Low Dropout: 400mV at 300mA
? Fast Line and Load Transient Response
? High Accuracy: ±1.5%
? 70μA Quiescent Current
• Short-Circuit, Over-Temperature, and Current Limit Protection
• TDFN34-16 Package
• -40°C to +85°C Temperature Range
Applications
• Bluetooth™ Headsets
• Cellular Phones
• Handheld Instruments
• MP3 and Portable Music Players
• PDAs and Handheld Computers
• Portable Media Players
Click to view :
AAT2554.pdf
