DATA SHEET AAT2158 1.5A Low-Noise,Step-Down Converter General Description Features The AAT2158 SwitchReg is a 1.5A step-down converter 1.5A Maximum Output Current with an input voltage range of 2.4V to 5.5V and an Input Voltage: 2.4V to 5.5V adjustable output voltage from 0.6V to V . The 1.4MHz Output Voltage: 0.6V to V IN IN switching frequency enables the use of small external Up to 95% Efficiency components. The small footprint and high efficiency make Low Noise Light Load Mode the AAT2158 an ideal choice for portable applications. 42A No Load Quiescent Current No External Compensation Required The AAT2158 delivers 1.5A maximum output current 1.4MHz Switching Frequency while consuming only 42A of no-load quiescent current. 100% Duty Cycle Low-Dropout Operation Ultra-low R integrated MOSFETs and 100% duty DS(ON) Internal Soft Start cycle operation make the AAT2158 an ideal choice for Over-Temperature and Current Limit Protection high output voltage, high current applications which <1 A Shutdown Current require a low dropout threshold. 16-Pin 3x3mm QFN Package The AAT2158 provides excellent transient response and Temperature Range: -40C to +85C high output accuracy across the operating range. No external compensation components are required. Applications The AAT2158 maintains high efficiency throughout the Cellular Phones load range. The AAT2158s unique architecture produces Digital Cameras reduced ripple and spectral noise. Over-temperature and Hard Disk Drives short-circuit protection safeguard the AAT2158 and sys- MP3 Players tem components from damage. PDAs and Handheld Computers Portable Media Players The AAT2158 is available in a Pb-free, space-saving USB Devices 16-pin 3x3mm QFN package. The product is rated over an operating temperature range of -40C to +85C. Typical Application U1 3.3V 2.5V AAT2158 12 4 VP FB R3 11 15 VP LX 187k 10 14 L1 VP LX 2.2H C1 7 13 EN LX 10F 9 16 VCC N/C R4 6 3 N/C PGND 59k C3 8 2 N/C PGND 22F 1 5 SGND PGND Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 1 202011A Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. May 28, 2012 N/C EN N/C SGND 13 8 LX 14 7 LX 15 6 LX 16 5 N/C DATA SHEET AAT2158 1.5A Low-Noise,Step-Down Converter Pin Descriptions Pin Symbol Function 1, 2, 3 PGND Main power ground return pin. Connect to the output and input capacitor return. (See board layout rules.) Feedback input pin. For an adjustable output, connect an external resistive divider to this pin. For xed 4FB output voltage versions, FB is the output pin of the converter. 5 SGND Signal ground. Connect the return of all small signal components to this pin. (See board layout rules.) 6, 8, 16 N/C Not internally connected. Enable input pin. A logic high enables the converter a logic low forces the AAT2158 into shutdown mode 7EN reducing the supply current to less than 1A. The pin should not be left oating. 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 PGND. Connect inductor to these pins. Switching node internally connected to the drain of both high- and low-side 13, 14, 15 LX 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 202011A Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. May 28, 2012