General Description
The AAT1153 SwitchReg™ is a 1.2MHz constant frequency current mode PWM step-down converter. It is ideal for portable equipment requiring very high current up to 2A from single-cell Lithium-ion batteries while still achieving over 90% efficiency during peak load conditions. The AAT1153 also can run at 100% duty cycle for low dropout operation, extending battery life in portable systems while light load operation provides very low output ripple for noise sensitive applications.

Features
• Input Voltage Range: 2.5V to 5.5V
• Output Voltages from 0.6V to VIN
• 2A Output Current
• High Efficiency: Up to 95%
• 1.2MHz Constant Switching Frequency
• Low RDS(ON) Internal Switches: 0.15Ω
• Allows Use of Ceramic Capacitors
• Current Mode Operation for Excellent Line and Load Transient Response
• Short-Circuit and Thermal Fault Protection
• Soft Start
• Low Dropout Operation: 100% Duty Cycle
• Low Shutdown Current: ISHUTDOWN < 1μA
• TDFN33-10 Package
• -40°C to +85°C Temperature Range

Applications
• Cellular Phones
• Digital Cameras
• DSP Core Supplies
• PDAs
• Portable Instruments
• Smart Phones