The AS1328 from Austriamicrosystems is a 1.5MHz synchronous DC/DC step-down converter. The buck regulator features 96% efficiency with a quiescent current of 25A. It can deliver up to 3A of output current at output voltages of 0.6V while operating from an input voltage of 2.7 to 5.5V over a -40 to 85°C temperature range. Fixed-output voltage versions are available in 50mV increments or, alternatively, the output voltage can be set from 0.6V to the input voltage via an external resistor divider, claims the company. The buck regulator also incorporates a Softstart feature that minimises the initial in-rush current and is available with a power okay function or low battery detection signal. Valuable board space is claimed to be conserved by incorporating internal compensation components as well as two switches with RDS(on) of 35mΩ. Housed in a 3x3mm TQFN package, the buck regulator features a fixed switching frequency of 1.5MHz, allowing the use of small surface mount inductors. The input voltage range of the step-down converter makes it suitable for applications powered by a single Li-Ion battery and in portable medical instruments, mobile internet devices and tablet PCs. The regulator is also suitable for solid state drives, set top boxes, base stations, telecomms and network equipment, FPGA, DDR, and P cores supplies.
