Step-Down Regulator Gives 97 Percent Efficiency
Austriamicrosystems has introduced the AS1339 step-down regulator. High efficiency and tiny packaging make the AS1339 ideal for multiband WCDMA/NCDMA applications, such as cellular handsets, wireless PDAs and smart phones. The AS1339 delivers up to 650mA from an input voltage range of 2.7 to 5.5V, making the device ideal for single Li-Ion cells. To improve battery lifetime, low-power RF amplifiers can scale the output power dynamically by changing its supply voltage. To support this, the output voltage of the AS1339 is dynamically controlled using an external analogue input signal. Additionally, the extremely fast 30us settling time of the output voltage ensures CDMA-specifications are not exceeded. The AS1339 is housed in a 2 x 2mm WL-CSP. It is designed for minimal space requirements in size-restricted battery-powered applications such as mobile phones and other portable wireless end equipment. The 2MHz fixed switching frequency minimises the PCB footprint by allowing the use of tin...