Buck Converter ICs Respond to Fast Transients

Designed to operate from single-cell Li-ion batteries, Advanced Analogic Technologies’ AAT1146 and AAT2512 stepdown dc-dc converters are optimized for extremely fast transient response, making them well suited for GSM phone applications. The AAT1146 stepdown converter supports an input voltage range of 2.7 V to 5.5 V and output levels as low as 0.6 V. The device delivers up to 400 mA of load current and maintains a no-load quiescent current of just 27 µA.

The AAT2512 is a dual-channel synchronous buck converter operating over the same 2.7-V to 5.5-V input range. Each regulator features independent input and enable pins. Each channel delivers 400 mA of load current, and the device supports quiescent current levels of 27 µA 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 1.4-MHz typical switching frequency to minimize the size of external components and keep switching losses low. They feature internal soft-start, and integrated overtemperature and current limit protection. The two devices also add 100% duty cycle low-dropout operation.

The AAT1146 is available in a 2.0-mm x 2.1-mm SC70JW-8 package and sells for $0.87 in 1000-unit quantities. The AAT2512 is offered in a TDFN33-12 package and sells for $1.64 in 1000-unit quantities.