General Description

The AAT1145 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 1.5A from single-cell Lithium-ion batteries while still achieving over 90 efficiency during peak load conditions. The AAT1145 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

• 1.5A Output Current

• High Efficiency: Up to 95

• 1.2MHz Constant Switching Frequency

• Low RDS(ON) Internal Switches: 135mΩ, 95mΩ

• 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