ADI LTC3548EDD-1#TRPBF

The LTC3548-1 is a dual, fixed output, constant-frequency, synchronous step-down DC/DC converter. Intended for low power applications, it operates from 2.5V to 5.5V input voltage range and has a constant 2.25MHz switching frequency, allowing the use of tiny, low cost capacitors and inductors with a profile ≤1mm. The output voltage for channel 1 is fixed at 1.8V and for channel 2 is fixed at 1.575V. Internal synchronous 0.35Ω, 1.2A/0.7A power switches provide high efficiency without the need for external Schottky diodes. Burst Mode operation provides high efficiency at light loads. To further maximize battery runtime, the P-channel MOSFETs are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only 40μA. In shutdown, the device draws <1μA. The LTC3548-1 is available in both thin (0.75mm) and ultrathin (0.55mm) 3mm×3mm DFN packages.

• High Efficiency: Up to 95%
• 1.81 at 800mA/1.575V at 400mA
• Very Low Quiescent Current: Only 40μA
• 2.25MHz Constant-Frequency Operation
• High Switch Current: 1.2A and 0.7A
• No Schottky Diodes Required
• VIN: 2.5V to 5.5V
• Current Mode Operation for Excellent Line and Load Transient Response
• Short-Circuit Protected
• Low Dropout Operation: 100% Duty Cycle
• Ultralow Shutdown Current: <1μA
• Small Thermally Enhanced 3mm×3mm DFN Packages

• PDAs/Palmtop PCs
• Digital Cameras
• Cellular Phones
• Portable Media Players
• PC Cards
• Wireless and DSL Modems