Power
Step-down converter has fast transient response to meet strict GSM specs
The power supply supporting a GSM handset baseband chipset must wake up to full load within microseconds. By integrating a fast transient 600mA step-down converter and a 300mA LDO, AnalogicTech’s AAT2505 forms a complete high-performance power supply solution for GSM handset baseband core and I/O.
AddiLow RDS(ON) integrated power switches on the AAT2505 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 minimise 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. Optimised 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 to +85 degrees C temperature range, the AAT2505 is immediately available in a Pb-free, 12-pin TDFN33 package.