LTC3407-2 Datasheet | Linear Technology

Features n High Efficiency: Up to 95% n Very Low Quiescent Current: Only 40μA n 2.25MHz Constant-Frequency Operation n High Switch Current: 1.2A on Each Channel n No Schottky Diodes Required n Low RDS(ON) Internal Switches: 0.35Ω n Current Mode Operation for Excellent Line and Load Transient Response n Short-Circuit Protected n Low Dropout Operation: 100% Duty Cycle n Ultralow Shutdown Current: IQ < 1μA n Output Voltages from 5V down to 0.6V n Power-On Reset Output n Externally Synchronizable Oscillator n Small Thermally Enhanced MSOP and 3mm × 3mm DFN Packages APPLICATIONS n PDAs/Palmtop PCs n Digital Cameras n Cellular Phones n Portable Media Players n PC Cards n Wireless and DSL Modems Dual Synchronous, 800m A, 2.25MHz Step-Down DC/DC Regulator DESCRIPTION The LTC®3407-2 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 profile ≤1.2mm. Each output voltage is adjustable from 0.6V to 5V. Internal synchronous 0.35Ω, 1.2A power switches provide high efficiency 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 efficiency. Burst Mode® operation provides high efficiency 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. L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION VIN = 2.5V- TO 5.5V C1 10μF VOUT2 = 2.5V AT 800m A L2 2.2μH C5, 22p F RUN2 VIN...