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Sky Works AAT2603

Total Power Solution for Portable Applications


TopologyBuck Converter
Input voltage2.7-5.5 V


The AAT2603 is a highly integrated power management solution for handheld mobile systems. It provides six regulated voltages from a single-cell Lithium-ion/polymer battery or a 5V supply.The six outputs are produced by six regulators; two switching step-down regulators and four low-dropout (LDO) regulators. Each voltage regulator has its own independent enable pin. The high efficiency step-down regulators are fully integrated and switch at a high 1.5 MHz fixed frequency.They automatically transition to variable frequency operation at light loads for improved efficiency. DC-DC1 (Buck1) is designed for high output current and low dropout voltage (200mV at 1.2A). DC-DC2 (Buck2) is a 600mA regulator with a two step dynamic output voltage capability. One option allows the output voltage of DC-DC2 (Buck2) to be set to either 1.0V or 1.3V with the SELB2 logic pin. LDO regulators LDO1 and LDO2 can supply up to 400mA of load current with output voltages adjustable down to 1.5V. LDO regulators LDO3 and LDO4 can supply up to 200mA of current and provide good noise and power supply rejection. LDO3 and LDO4 have output voltages externally adjustable down to 1.2V.The AAT2603 is available in a Pb-free, thermally enhanced 28-pin TQFN44 package and is rated for operation over the -40°C to +85°C temperature range.


  • VIN Range: 2.7V to 5.5V
  • Two Step-Down Regulators
  • DC-DC1(Buck1): 1.2A, Low Dropout Voltage
  • Externally Adjustable: VFBB1 = 0.6V
  • VOUT Range: 0.6V to VINB1
  • Fixed: VOUT = 3.3V
  • Factory Programmable to any Voltage Level
  • from 0.6V to 4.0V
  • DC-DC2(Buck2): 0.6A, Low Dropout Voltage
  • Externally Adjustable: VFBB2 = 0.6V
  • VOUT Range: 0.6V to VINB2
  • Fixed: VOUT = 1.0V[SELB2=’1’]/1.3V[SELB2=’0’]
  • Factory Programmable to any Two Voltage
  • Levels from 0.6V to 4.0V
  • Fixed 1.5MHz Switching Frequency
  • Internally Compensated Current Mode Control
  • High Efficiency over the Entire Load Range
  • Four LDO Regulators
  • LDO1: 400mA LDO
  • LDO2: 400mA LDO
  • LDO3: 200mA, Low Noise LDO
  • LDO4: 200mA, Low Noise LDO
  • Fast Turn-On and Turn-Off time
  • Short Circuit and Over-Current Protection
  • Over-Temperature Protection
  • Temperature Range: -40°C to +85°C
  • TQFN44-28 Package


  • Refer page num 18 for more inductor values with parts and series.

Typical applications

  • Handheld GPS
  • Smart Phones
  • Portable Media Players
  • Handheld Instruments
  • PDAs and Handheld Computers