SC1486 Datasheet | SEMTECH

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 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 shoot-through protection and soft switching. Additional Features include cycle-bycycle current limit, digital soft-start, overvoltage and under-voltage protection, and a PGOOD output for each controller. Features ‹ Constant on-time for fast dynamic response ‹ VIN range = 1.8V - 25V ‹ DC current sense using low-side RDS(ON) sensing ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ ‹ or sense resistor Integrated reference buffer for VTT Low power S3 state Resistor programmable frequency Cycle-by-cycle current limit Digital soft-start PSAVE option for VDDQ Over-voltage/under-voltage fault protection <20u A shutdown current Low quiescent power dissipation Two separate PGOOD indicators Separate enable of each switcher Integrated gate drivers with soft switching Efficiency >90% 1% Internal reference 28 Lead TSSOP Industrial temperature...