SC1485

www.DataSheet4U.com Dual Synchronous Buck Pseudo Fixed Frequency Power Supply Controller POWER MANAGEMENT Description The SC1485 is a dual output constant on synchronousbuck PWM controller intended for use in notebook computers and other battery operated portable devices. Features include high efficiency and a fast dynamic response with no minimum on time. The excellent transient response, means that SC1485 based solutions will require less output capacitance than competing 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. After the transient event, the controller frequency will return to steady state operation. At light loads, Power-Save Mode enables the SC1485 to skip PWM pulses for better efficiency. Each output voltage can be independently adjusted from 0.5V to VCCA. 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-by-cycle current limit, digital soft-start, over-voltage and undervoltage protection, and a PGOOD output for each controller. SC1485 Features Constant on-time for fast dynamic response Programmable VOUT range = 0.5 – VCCA VIN Range = 1.8V – 25V DC current sense using low-side RDS(ON) sens...