SC1486
Description
The SC1486 is a dual output constant on synchronousbuck PWM controller optimized for cost effective mobile DDR 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 SC1486 based solutions will require less output capacitance than peting fixed frequency converters. The frequency is constant until a step in load or line voltage occurs at which time the pulse density and frequency will increase or decrease to counter the change in output or input voltage. 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. A resistor divider from the 2.5 volt 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...
