New Industry Products

LTC Unveils LTC3403 Synchronous Buck Regulator

March 27, 2003 by Jeff Shepard

Linear Technology Corp. (LTC, Milpitas, CA) announced the LTC3403, a high-efficiency, 1.5MHz, synchronous buck regulator with an integrated bypass MOSFET that can deliver up to 600mA of continuous output current from a tiny eight-lead DFN package. Using a constant-frequency, current-mode architecture, the LTC3403 operates from an input-voltage range of 2.5V to 5V, making it suitable for single-cell, lithium-ion, cellular applications.

The output can be dynamically programmed from 0.3V to 3.5V to optimize the efficiency of the latest generation of CDMA and WCDMA power amplifiers, thereby increasing battery life. At output voltages above 3.6V, an internal bypass p-channel MOSFET transistor connects VOUT directly to VBATTERY with a dropout of less than 100mV (at 600mA), minimizing power loss through the inductor. The switching frequency of 1.5MHz allows the utilization of tiny, low-cost capacitors and inductors less than 1mm in height. The combination of the tiny externals and a 3mm x 3mm DFN package make the LTC3403 optimal for space-constrained cellular phones.

The LTC3403 is available from stock in an eight-lead DFN package. Pricing starts at $2.10 for 1,000-piece quantities.