Linear Announces Synchronous Step-Down DC-DC Converter to Deliver up to 500mA with Pin Selectable 1.28V/1.87 Outputs

Linear Technology 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 1.28 or 1.87V, making it well-suited 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 2.5 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 0.35Ω (N-Channel) and 0.50Ω (P-Channel) to deliver efficiencies as high as 96%. It also utilizes low dropout 100% 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% 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.