DATA SHEET AAT1146 Fast Transient 400mA Step-Down Converter General Description Features The AAT1146 SwitchReg is a 1.4MHz step-down con- V Range: 2.7V to 5.5V IN verter with an input voltage range of 2.7V to 5.5V and V Fixed or Adjustable from 0.6V to V OUT IN output voltage as low as 0.6V. It is optimized to react 27A No Load Quiescent Current quickly to a load variation. Up to 98% Efficiency 400mA Max Output Current The AAT1146 is available in fixed voltage versions with 1.4MHz Switching Frequency internal feedback and a programmable version with 120s Soft Start external feedback resistors. It can deliver 400mA of load Fast Load Transient current while maintaining a low 27A no load quiescent Over-Temperature Protection current. The 1.4MHz 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 AAT1146 is designed to maintain high efficiency SC70JW-8 and SOT23-5 Packages throughout the operating range, which is critical for por- Temperature Range: -40C to +85C table applications. The AAT1146 is available in the Pb-free, space-saving Applications 2.0 x 2.2mm SC70JW-8 and SOT23-5 packages and is Cellular Phones rated over the -40C to +85C temperature range. Digital Cameras Handheld Instruments Microprocessor / DSP Core / IO Power PDAs and Handheld Computers USB Devices Typical Application (Fixed Output Voltage) U1 AAT1146 L1 V V IN VIN LX O 4.7H OUT EN C2 C1 4.7F 4.7F PGND AGND PGND PGND Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 1 201985B Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. March 18, 2013 DATA SHEET AAT1146 Fast Transient 400mA Step-Down Converter Pin Descriptions Pin SC70JW-8 SOT23-5 Symbol Function 1 2 EN Enable pin. Feedback input pin. This pin is connected either directly to the converter output or to an 2 4 OUT external resistive divider for an adjustable output. 3 5 VIN Input supply voltage for the converter. Switching node. Connect the inductor to this pin. It is internally connected to the drain of 43 LX both high- and low-side MOSFETs. 5 AGND Non-power signal ground pin. 1 6, 7, 8 PGND Main power ground return pins. Connect to the output and input capacitor return. Pin Configuration SC70JW-8 SOT23-5 (Top View) (Top View) 8 1 PGND EN 1 5 VIN GND 2 7 OUT PGND 3 2 6 EN PGND VIN 45 LX AGND 3 4 LX OUT Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 2 201985B Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. March 18, 2013