SC483

POWER MANAGEMENT Description Dual Synchronous Buck Pseudo Fixed Frequency Power Supply Controller Features Constant on-time for fast dynamic response Programmable VOUT range = 0.5 – VCCA VBAT Range = 1.8V – 25V DC current sense using low-side RDS(ON) sensing or sense resistor Resistor programmable frequency Cycle-by-cycle current limit Digital soft-start Separate PSAVE option for each switcher Over-voltage/Under-voltage fault protection 10µA Typical shutdown current Low quiescent power dissipation Two Power Good indicators 1% Reference (2% system DC accuracy) Integrated gate drivers with soft switching Separate enables 28 Lead TSSOP Industrial temperature range Output soft discharge upon shutdown SC483 The SC483 is a dual output constant-on synchronous buck 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 SC483 based solutions will require less output capacitance than competing fixed frequency converters. www.DataSheet4U.com The switching 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 SC483 to skip PWM pulses for better effi...