DC-DC buck regulators

The AS1332-34 family of step down DC-DC regulators optimised for noise sensitive RF power amplifiers in single-cell Li-Ion battery-powered applications has been released by austriamicrosystems.

The thee devices in the family deliver up to 650 mA from an input voltage range of 2.7 to 5.5 making the devices suitable for single Li-Ion cells. The AS1332 is optimised for low-power RF amplifiers where the output power is scaled by the supply voltage to improve battery life.

The external analog reference voltage is applied to the Vcon input, on which the output voltage follows the reference voltage within 20 µs (multiplied by an internal gain of 2.5), varying the output between 1.3 to 3.16 V.

This fast rise and fall time ensures operational margin.

The output voltage of the AS1333 is fixed at 3.09 whereas the AS1334 is available in 1.2, 1.5, 1.8, 2.5, 3.0 and 3.3 V output voltage versions.

The family is designed for minimal space requirements in powered applications and is suitable for mobile phones and other portable wireless end equipment. The 2 MHz fixed switching frequency minimises PCB footprint by allowing the use of tiny, low-profile inductors and capacitors. This constant frequency switching, together with internal noise-reducing circuitry, results in an output voltage ripple of less than 2 mV peak-to-peak.