
Fairchild Semiconductor
General Description
The FAN5068 DDR memory regulator combines a highefficiency PWM controller to generate the supply voltage, VDDQ, and a linear regulator to generate VTT, the termination voltage. Synchronous rectification provides high-efficiency over a wide range of load currents. Efficiency is further enhanced by using the low-side MOSFET’s RDS(ON) to sense current instead of a series sense resistor.
FEATUREs
• PWM regulator for VDDQ (2.5V or 1.8V)
• Linear LDO regulator generates VTT = VDDQ/2, 1.5A Peak sink/source capability
• 1 independent programable ULDO controllers driving external N-Channel MOSFET
• ACPI drive and control for 5V DUAL generation
• 3.3V Internal LDO for 3V-ALW generation
• 300kHz fixed frequency switching
• RDS(ON) current sensing or optional current sense resistor for precision over-current detect
• Internal Synchronous Boot diode
• Power Good signal for all voltages
• Input Under-Voltage Lock-Out (UVLO)
• Thermal Shutdown
• Latched Multi-Fault Protection
• 24-pin 5x5mm MLP package
APPLICATIONs
• DDR-1/DDR-2 VDDQ and VTT voltage generation with ACPI support
• Desktop PCs
• Servers