AnalogicTech Unveils Low Quiescent Converters for GSM Handsets

Advanced Analogic Technologies Inc. today introduced two new dc-dc converters for portable systems powered by single-cell lithium-ion/polymer batteries. Optimized for extremely fast transient response, the AAT1146 and AAT2512 step-down converters are well suited for GSM phone applications.

"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 for AnalogicTech. "The AAT1146 and AAT2512 devices allow design engineers to easily meet these stringent requirements, while keeping the converter output in regulation."

The AAT1146 step-down converter supports an input voltage range of 2.7V to 5.5V and output levels as low as 0.6V. The device delivers up to 400mA of load current and maintains a no-load quiescent current of just 27µA.

The AAT2512 is a dual-channel synchronous buck converter operating over the same 2.7V to 5.5V input range. Each regulator features independent input and enable pins. Each channel delivers 400mA of load current, and the device supports quiescent current levels of 27µA for light load conditions.

Both the AAT1146 and the AAT2512 are available in fixed or programmable versions with efficiency as high as 98%. The devices use a high 1.4MHz typical switching frequency to minimize the size of external components and keep switching losses low. They feature internal soft-start to eliminate output voltage overshoot, and integrated over-temperature and current limit protection. The two devices also add 100% duty cycle low-dropout operation.

The AAT1146 and AAT2512 are rated across the -40°C to +85°C temperature range. The AAT1146 is available in a Pb-free, compact 2.0x2.1mm SC70JW-8 package and sells for $0.87 in 1000-unit quantities. The AAT2512 is offered in a Pb-free, TDFN33-12 package and sells for $1.64 in 1000-unit quantities.