AAT1145IDE-1.8-T1

PRODUCT DATASHEET AAT1145 SwitchRegTM 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. The AAT1145 can supply up to 1.5A output load current from a 2.5V to 5.5V input voltage and the output voltage can be regulated as low as 0.6V. The high switching frequency minimizes the size of external components while keeping switching losses low. The internal slope compensation setting allows the device to operate with smaller inductor values to optimize size and provide efficient operation. The AAT1145 is available in adjustable (0.6V to VIN) and fixed (1.8V) output voltage versions. The device is available in a Pb-free, 3x3mm 10-lead TDFN package and is rated over the -40°C to +85°C temperature range. 1.5A Step-Down Converter 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 Typical Application L1 2.2μH 1 2 3 VIN 2.5V-5.5V VOUT 1.8V,1.5A EN IN AIN LX LX 8 7 5 10 9 C1 10μF AAT1145-1.8 OUT PGND PGND C2 22μF 6 4 AGND AGND 1145.2008.01.1.2 www.analogictech.com 1 PRODUCT DATASHEET AAT1145 AAT1145 SwitchRegTM Pin Descriptions Pin # 1 2 3 4, 6 5 7, 8 9, 10 1.5A Step-Down Converter Symbol EN IN AIN AGND FB/OUT LX PGND EP Function Enable pin. Active high. In shutdown, all functions are disabled drawing