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 3.3V_DUAL/3.3V_SB voltage plane from the ATX supply's 5V_SB 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 3.3V_DUAL/3.3V_SB 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. A controller powers up the 5V_DUAL

plane by switching in the ATX 5V output through an NMOS transistor in active states, or by switching in the ATX 5V_SB through a PMOS (or PNP) transistor in S3 sleep state. In S4/S5 sleep states, the ISL6504 5V_DUAL output is shut down. In the ISL6504A, the 5V_DUAL output stays on during S4/S5 sleep states. This is the only difference between the two parts; see Table 1.

An internal linear regulator supplies the 1.2V for the voltage identification circuitry (VID) only during active states (S0 and S1/S2), and uses the 3V3 pin as input source for its internal pass element. Another internal regulator outputs a 1.5V_SB chip-set standby supply, which uses the 3V3DL pin as input source for its internal pass element. The 3.3V_DUAL/3.3V_SB and 1.5V_SB outputs are active for as long as the ATX 5V_SB voltage is applied to the chip.

• Provides four ACPI-Controlled Voltages
  • 5V_DUAL USB/Keyboard/Mouse
  • 3.3V_DUAL/3.3V_SB PCI/Auxiliary/LAN
  • 1.2V_VID Processor VID Circuitry
  • 1.5V_SB 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)

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