高速過渡応答、DDRメモリDC-DC電源、コンデンサコストを低減
SUNNYVALE, CA-February 27, 2002-Maxim Integrated Products introduces the MAX1917, which generates DDR memory termination voltages (VTT and VTTR) within 1% of 0.5VDDQ for use in servers, notebooks, and desktop computers. It uses a unique Quick-PWM™ architecture for the fastest transient response with the smallest output capacitors, saving cost and space. The MAX1917’s output varies only ± 35mV from its nominal value during a -7A to +7A transient, while using only four 270µF capacitors. The required output capacitance occupies about 75% less volume than competing solutions.
The MAX1917 is also very efficient, reducing heat in nonportable equipment and extending battery life in portable applications. Step-down DC-DC conversion efficiency is as high as 96%, and shutdown current is only 5µA. The output current is monitored without sense resistors, and the current limit is programmable. The MAX1917 uses a dual N-channel synchronous rectified control scheme to reduce switch cost and improve efficiency.
Other integrated features include an internal soft-start, integrated VTTR reference, Power-OK signal indicating output is properly regulated, and a DDR reference input. The input range is 1.5V to 14V, and its output range is 0.75V to 5V with up to 25A sink-and-source capability.
These devices come in a small 16-pin QSOP package and are specified for the extended-industrial temperature range (-40°C to +85°C). Prices start at $1.69 (1000-up, FOB USA). The MAX1917 Evaluation Kit is available to speed designs.
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