Sunnyvale, Calif.—Advanced Analogic Technologies' AAT1146 and AAT2512 DC/DC converters, with a fast transient response ideally suited for GSM phone applications, respond quickly to demanding load swings.
"The power supply supporting a GSM phone baseband chipset must almost instantaneously ramp from a few milliamps to full load, so extremely fast transient response is critical," notes David Brown, senior manager of Applications Engineering. "The AAT1146 and AAT2512 devices allow design engineers to easily meet these stringent requirements, while keeping the converter output in regulation." The transient response is specified as less than 80 mV output droop and steady state recovery in 20 microseconds for a 1.8-volt output with a 1 mA to 300 mA pulsed load.
The AAT1146 step-down converter, which can be powered from a single lithium-ion/polymer battery (2.7- to 5.5-volt input), delivers up to 400 mA at voltages down to 0.6 volt. No-load quiescent current is just 27 microamps. The AAT2512 dual-channel synchronous buck converter, working over the same operating voltage range, features independent input and enable pins. Each channel delivers 400 mA.
Both the AAT1146 and the AAT2512 are available in fixed or programmable versions with efficiency as high as 98 percent. Switching frequency is 1.4 MHz, thus minimzing the size of external components. The chips feature internal soft-start to eliminate output voltage overshoot. They also carry over-temperature and current- limit protection.
Click here for the AAT1146 datasheet and here for the AAT2512. The AAT1146 and AAT2512 are rated for operation over -40 to +85°C. The AAT1146, in a Pb-free, compact 2-by-2.1 mm SC70JW-8 package, is priced at 87 cents each in 1k quantities. The AAT2512, offered in a Pb-free, TDFN33-12 package, is $1.64.
Advanced Analogic Technologies, 1-408-737-4600, www.analogictech.com