LTC3407IDD-2#PBF

The LTC3407-2 is a dual, 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 prof lie ≤1.2mm. Each output voltage is adjustable from 0.6V to 5V. Internal synchronous 0.35Ω, 1.2A power switches provide high eff iciency without the need for external Schottky diodes. A user selectable mode input is provided to allow the user to trade-off noise ripple for low power eff iciency. Burst Mode operation provides high eff iciency at light loads, while pulse-skipping mode provides low noise ripple at light loads. To further maximize battery life, 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.

Applications

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

Key features

• High Eff iciency: Up to 95%
• Very Low Quiescent Current: Only 40μA
• 2.25MHz Constant-Frequency Operation
• High Switch Current: 1.2A on Each Channel
• No Schottky Diodes Required
• Low RDS(ON) Internal Switches: 0.35Ω
• Current Mode Operation for Excellent Line and Load Transient Response
• Short-Circuit Protected
• Low Dropout Operation: 100% Duty Cycle
• Ultralow Shutdown Current: IQ<1μA
• Output Voltages from 5V down to 0.6V
• Power-On Reset Output
• Externally Synchronizable Oscillator
• Small Thermally Enhanced MSOP and 3mm×3mm DFN Packages