Description

The SC488 is a combination switching regulator and linear source/sink regulator intended for DDR1/2 memory systems. The purpose of the switching regulator is to generate the supply voltage, VDDQ, for the memory system. It is a pseudo-fixed frequency constant on-time controller designed for high efficiency, superior DC accuracy, and fast transient response. The purpose of the linear source/sink regulator is to generate the memory termination voltage, VTT, with the ability to source and sink 2.8A peak currents.

Features

♦ Constant On-Time Controller for Fast Dynamic Response on VDDQ

♦ DDR1/DDR2/DDR3 Compatible

♦ VDDQ = Fixed 1.8V or 2.5V, or Adjustable From 1.5V to 3.0V

♦ 1.5% Internal Reference (2.5% System Accuracy)

♦ Resistor Programmable On-Time for VDDQ

♦ VCCA/VDDP Range = 4.5V to 5.5V

♦ VIN Range = 2.5V to 25V

♦ VDDQ DC Current Sense Using Low-Side RDS(ON) Sensing

♦ External RSENSE in Series with Low-Side FET

♦ Cycle-by-Cycle Current Limit for VDDQ

♦ Digital Soft-Start for VDDQ

♦ Analog Soft-Start for VTT/REF

♦ Smart Over-Voltage VDDQ Protection

♦ Combined EN and PSAVE Pin for VDDQ

♦ Over-Voltage/Under-Voltage Fault Protection

♦ Power Good Output

♦ Separate VCCA and VDDP Supplies

♦ VTT/REF Range = 0.75V – 1.5V

♦ VTT Source/Sink 2.8A Peak

♦ Internal Resistor Divider for VTT/REF

♦ VTT is High Impedance in S3

♦ VDDQ, VTT, REF are Actively Discharged in S4/S5

♦ 24 Lead MLPQ (4x4 mm) Lead-Free Package

♦ Product Is Fully WEEE and RoHS Compliant

Applications

♦ Notebook Computers

♦ CPU I/O Supplies

♦ Handheld Terminals and PDAs

♦ LCD Monitors

♦ Network Power Supplies