Linear Technology Corp. (LTC, Milpitas, CA) announced the LTC3413, a high efficiency, monolithic synchronous, step-down, switching regulator that is capable of generating a bus termination voltage for DDR/DDR2 memory applications. It has the ability to source or sink up to 3A of output current. The LTC3413 allows switching frequencies as high as 2MHz for small externals and compact solution footprints. The internal power switches have an RDS(on) of only 85 mOhms providing efficiencies of 90 percent while generating an output voltage of 0.6V. The LTC3413 is offered in a thermally enhanced, TSSOP-16E package.
The LTC3413 utilizes a constant-frequency, current-mode architecture that operates from an input-voltage range of 2.25V to 5.5V and provides a regulated output voltage equal to VREF/2. The switching frequency can be set between 300kHz and 2MHz by a single external resistor. Output-voltage ripple is inversely proportional to the switching frequency and the inductor value. Having the ability to increase the switching frequency as high as 2MHz allows lower inductor values to be used while maintaining low output-voltage ripple. To further reduce footprint area, an internal voltage divider halves the reference voltage, eliminating the need for an external resistor divider. The LTC3413 provides compact DDR termination solutions for space-constrained applications such as notebook computers and memory cards.
The LTC3413 is available from stock in a 16-lead, thermally enhanced, TSSOP package. Pricing starts at $3.95 each in 1,000-piece quantities.
