Linear Technology has announced the LTC3563, a high efficiency, 2.25 MHz, synchronous buck regulator that can deliver up to 500mA of continuous output current from a 2mm x 2mm DFN package. Its output voltage is pin-selectable to either 1.28V or 1.87V, making it ideal for the latest generation of Agere cellphone baseband chipsets.

Using a constant frequency and current mode architecture, the LTC3563 operates from an input voltage range of 2.5V to 5.5V, compatible with single cell Li-Ion, or multi-cell alkaline/NiCad/NiMH applications. Its 2.25MHz switching frequency enables the utilization of tiny, low cost ceramic capacitors and inductors less than 1mm in height, providing a very compact solution footprint for handheld applications.

The LTC3563 uses internal switches with an RDS(ON) of only 0.35 Ohm (N-Channel) and 0.50 Ohm (P-Channel) to deliver efficiencies as high as 96 per cent. It also utilizes low dropout 100 per cent duty cycle operation to allow output voltages equal to VIN, further extending battery run time.

The LTC3563 utilizes low ripple (<20mVPK-PK) Burst Mode® operation, drawing only 26uA of no load quiescent current. Shutdown current is less than 1uA further maximizing battery run time. Other features include ±2 per cent output voltage accuracy, internal soft-start and over-temperature protection.

The LTC3563EDC is available in a 2mm x 2mm DFN-6 package and is available from stock. Pricing starts at $1.60 each in 1,000-piece quantities.

Features of the LTC3563:
 
* Pin-Selectable Output Voltage: 1.28V/1.87V
* Low Ripple (<20mVp-p) Burst Mode Operation: IQ = 26uA
* 2.5V to 5.5V Input Voltage Range
* High Efficiency: Up to 96 per cent
* 2.25MHz Constant Frequency Operation
* Low Dropout Operation: 100 per cent Duty Cycle
* No Schottky Diode Required
* Internal Soft-Start Limits Inrush Current
* Shutdown Mode Draws <1uA Supply Current
* Current Mode Operation for Excellent Line and Load Transient Response
* Overtemperature Protected
* Available in 2mm x 2mm 6-Lead DFN

Contact information

For further information, contact Alastair Boyd, Area Sales Manager UK and Ireland, Linear Technology +44 (0)1628 477066  or aboyd@linear.com.