DATA SHEET AAT2148 Low-Noise, Fast Transient 1A Step-Down Converter General Description Features The AAT2148 SwitchReg is a 2MHz step-down converter V Range: 2.7V to 5.5V IN with an input voltage range of 2.7V to 5.5V and output Low Noise Light Load Mode voltage as low as 0.6V. It is optimized to react quickly to Low Ripple PWM Mode a load variation. The AAT2148 incorporates a unique low V Fixed or Adjustable from 0.6V to V OUT IN noise architecture which reduces ripple and spectral 37A No Load Quiescent Current noise. Up to 98% Efficiency 1A Max Output Current The AAT2148 is available in fixed voltage versions with 2MHz Switching Frequency internal feedback and a programmable version with 150s Soft Start external feedback resistors. It can deliver 1A of load cur- Fast Load Transient rent while maintaining a low 37A no load quiescent Over-Temperature Protection current. The 2MHz switching frequency minimizes the Current Limit Protection size of external components while keeping switching 100% Duty Cycle Low-Dropout Operation losses low. <1 A Shutdown Current The AAT2148 is designed to maintain high efficiency QFN33-16 Package throughout the operating range, which is critical for por- Temperature Range: -40C to +85C table applications. The AAT2148 is available in the Pb-free, thermally Applications enhanced 3x3mm QFN-16 package and is rated over the Cellular Phones -40C to +85C temperature range. Digital Cameras Handheld Instruments Microprocessor / DSP Core / IO Power PDAs and Handheld Computers USB Devices Typical Application (Adjustable Output Voltage) U1 AAT2148 L1 4.7H V 12 13 V IN O VP LX 2.7V - 5.5V 1.8V, 1A C1 11 14 R1 VP LX C2 4.7F 118k 10 15 4.7F VP LX 9 4 VCC FB R2 7 2 EN PGND 59k 3 1 PGND PGND Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 1 202009A Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. May 28, 2012 N/C EN N/C N/C 13 8 LX 14 7 LX 15 6 LX 16 5 N/C DATA SHEET AAT2148 Low-Noise, Fast Transient 1A Step-Down Converter Pin Descriptions Pin Symbol Function 1, 2, 3 PGND Power ground pin Feedback input. This pin is connected either directly to the converter output or to an external resis- 4FB tive divider for an adjustable output. 5, 6, 8, 16 N/C Not internally connected. 9 VCC Bias supply. Supplies power for the internal circuitry. Connect to input power. 10, 11, 12 VP Input supply voltage for the converter power stage. Must be closely decoupled to GND. Switching node. Connect the inductor to this pin. It is internally connected to the drain of both 13, 14, 15 LX high- and low-side MOSFETs. EP Exposed paddle (bottom) connect to PGND directly beneath package. Pin Configuration QFN33-16 (Top View) 1 12 PGND VP 2 11 VP PGND 3 10 VP PGND 4 9 FB VCC Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 2 202009A Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. May 28, 2012