SC1486A
Description
The SC1486A is a dual output constant on-time synchronous buck PWM controller optimized for cost effective mobile DDR and DDR2 applications. Features include high efficiency, a fast dynamic response with no minimum on time, a REFIN input and a buffered REFOUT pin capable of sourcing 3m A. The excellent transient response means that SC1486A based solutions will require less output capacitance than peting fixed frequency converters. The output voltage of the first controller can be adjusted from 0.5V to VCCA. In DDR applications, this voltage is set to 2.5 volts, and in DDR2, 1.8V. A resistor divider from this supply is used to drive the REFIN pin of the second controller. A unity gain buffer drives the REFOUT pin to the same potential as REFIN. The second controller regulates its output to REFOUT. Two frequency setting resistors set the on-time for each buck controller. The frequency can thus be tailored to minimize crosstalk. The integrated gate drivers feature adaptive...
