Tracking, Sinking and Sourcing, Synchronous Buck Controller for DDR Memory and Termination Supplies

The MAX1917 provides a complete power-management solution for DDR memory. It contains a synchronous buck controller and an amplifier to generate 1/2VDDR voltage for VTT and VTTR. The VTT and VTTR voltages are maintained within 1% of 1/2VDDR. The controller operates in synchronous rectification mode to ensure balanced current sourcing and sinking capability of up to 25A. With a shutdown current of less than 5µA, the MAX1917 is the best choice for low-power notebook applications, as well as servers and desktop computers. An all N-FET design optimizes efficiency. The MAX1917 can also be used for generating VDDR and as a general-purpose step-down controller with variable switching frequency as high as 1MHz with few additional components.

The MAX1917 uses Maxim's proprietary Quick-PWM™ architecture for fast transient response up to 96% efficiency, and the smallest external components. Output current monitoring is achieved without sense resistors by monitoring the bottom FET's drain-to-source voltage. The current-limit threshold is programmable through an external resistor. The MAX1917 comes in a space-saving 16-pin QSOP package.

Applications

* AGTL Bus Termination Supplies * Cell Phone Base Stations * DDR Memory Power Supplies * Desktop Computers * Networking Systems * Notebook Computers * Processor or DSP Core Supply * Storage