ACPI Regulator/Controller for Dual Channel DDR Memory Systems

   The ISL6537 provides a complete ACPI compliant power solution for up to 4 DIMM dual channel DDR/DDR2 Memory systems. Included are both a synchronous buck controller to supply VDDQ during S0/S1 and S3 states. During S0/S1 state, a fully integrated sink-source regulator generates an accurate (VDDQ/2) high current VTT voltage without the need for a negative supply. A buffered version of the VDDQ/2 reference is provided as VREF. Two LDO controllers are also integrated for the GMCH core voltage regulation and for the GMCH and CPU VTT termination voltage regulation.

FEATUREs
• Generates 4 Regulated Voltages
   - Synchronous Buck PWM Controller for DDR VDDQ
   - 3A Integrated Sink/Source Linear Regulator with
      Accurate VDDQ/2 Divider Reference for DDR VTT
   - LDO Regulator for GMCH Core
   - LDO Regulator for CPU/GMCH VTT Termination
• ACPI Compliant Sleep State Control
• Glitch-free Transitions During State Changes
• Integrated VREF Buffer
• PWM Controller Drives Low Cost N-Channel MOSFETs
• 250kHz Constant Frequency Operation
• Tight Output Voltage Regulation
   - All Outputs: ±2% Over Temperature
• Fully-Adjustable Outputs with Wide Voltage Range: Down
   to 0.8V supports DDR and DDR2 Specifications
• Simple Single-Loop Voltage-Mode PWM Control Design
• Fast PWM Converter Transient Response
• Under and Overvoltage Monitoring on All Outputs
• OCP on the Switching Regulator
• Integrated Thermal Shutdown Protection
• Pb-Free Plus Anneal Available (RoHS Compliant)

APPLICATIONs
• Single and Dual Channel DDR Memory Power Systems in
   ACPI Compliant PCs
• Graphics Cards - GPU and Memory Supplies
• ASIC Power Supplies
• Embedded Processor and I/O Supplies
• DSP Supplies