Analogic Tech Announces Step-Down Converter, LDO for GSM Applications

Advanced Analogic Technologies Inc. announced the AAT2505, the latest addition to the company's growing SystemPower™ family of power management IC products. Combining a fast transient 600mA step-down converter with a fast transient 300mA low dropout (LDO) linear regulator, the AAT2505 offers a highly compact solution optimized for popular GSM mobile phone applications.

"The power supply supporting a GSM handset baseband chipset must wake up to full load within microseconds," said Bill Weiss, Product Line Director for AnalogicTech. "By integrating a fast transient 600mA step-down converter and a 300mA LDO, the AAT2505 forms a complete high-performance power supply solution for GSM handset baseband core and I/O. In addition, the AAT2505 consumes 50% less PCB area than discrete solutions, and avoids the arduous PCB layout overhead associated with 'mega' power management units."

Low RDS(ON) integrated power switches on the AAT2505 step-down converter extend battery life and handset talk time by supporting efficiency levels up to 98 percent. With a wide output voltage range of 0.6V to VIN, the 600mA converter also maintains a low 27µA no load quiescent current. Its 1.4MHz switching frequency helps minimize the size and cost of external components. Turn-on time is 150µs (typical).

The LDO delivers up to 300mA of current and features an independent input pin. Optimized to support the fast line/load transient requirements of a GSM chipset, the LDO features low quiescent current and a power-OK (POK) output to signal when the output voltage is in regulation.

The AAT2505 also adds internal soft-start, over-temperature, and current limit protection. Specified over the -40°C to +85°C temperature range, the AAT2505 is immediately available in a Pb-free, 12-pin TDFN33 package. The device sells for $1.14 each in 1000-piece quantities.