The ISL6504 and ISL6504A complement other power building blocks (voltage regulators) in ACPI-compliant designs for microprocessor and computer applications. The IC integrates three linear controllers/regulators, switching, monitoring and control functions into a 16-pin wide-body SOIC or 20-pin QFN 6x6 package. The ISL6504, ISL6504A operating mode (active outputs or sleep outputs) is selectable through two digital control pins, S3 and S5.
One linear controller generates the 3.3VDUAL/3.3VSB voltage plane from the ATX supply’s 5VSB output, powering the south bridge and the PCI slots through an external NPN pass transistor during sleep states (S3, S4/S5). In active state (during S0 and S1/S2), the 3.3VDUAL/3.3VSB linear regulator uses an external N-channel pass MOSFET to connect the outputs directly to the 3.3V input supplied by an ATX power supply, for minimal losses.

Features
• Provides four ACPI-Controlled Voltages
   - 5VDUAL USB/Keyboard/Mouse
   - 3.3VDUAL/3.3VSB PCI/Auxiliary/LAN
   - 1.2VVID Processor VID Circuitry
   - 1.5VSB ICH4 Resume Well
• Excellent Output Voltage Regulation
   - All Outputs: 2.0% over temperature (as applicable)
• Small Size; Very Low External Component Count
• Undervoltage Monitoring of All Outputs with Centralized
   FAULT Reporting and Temperature Shutdown
• QFN Package:
   - Near Chip Scale Package Footprint; Improved PCB
      Efficiency; Thinner profile
• Pb-Free Available (RoHS Compliant)

Applications
• ACPI-Compliant Power Regulation for Motherboards
   - ISL6504: 5VDUAL is shut down in S4/S5 sleep states
   - ISL6504A: 5VDUAL stays on in S4/S5 sleep states