A combination dc-dc converter and ACPI switch targets the power-supply demands of the next generation of PC motherboard architectures.
The RC5058 has an on-board 5-bit digital-to-analog converter that matches the processor supply voltage from 1.3 to 3.5 V through programming by the microprocessor. Two of the on-board LDOs provide 1.5 and 2.5 fixed voltages for VTT termination and VCLOCK. The third user-selectable 1.5- to 3.3-V LDO is available for VNORTHBRIDGE (1.8 V) or VAGP (selectable 1.5 to 3.3 V). The RC5058 also features remote voltage sense, programmable Active Droop, current sense, and overvoltage/undervoltage lockout protection.
Meanwhile, the RC5060 is integrated-ACPI compliant. It features two dual switches and two LDOs that address the USB, PCI, SDRAM, and RAMBUS power buses. Its 5-V dual controls the USB 5-V main/5-V standby, the 3.3-V dual controls PCI. The PCI and SDRAM are both a combination switch 3.3-V main and an LDO capable of delivering 3.3 V from a 5-V standby. The RC5060 also features four dual supplies, along with utilizing and driving n-channel MOSFETs to optimize cost.
Both models are available for delivery. The RC5058 and RC5060 cost $2.50 and $2.70 each respectively in 1000-piece quantities.
Fairchild Semiconductor, 333 Western Ave., South Portland, Maine 04106; (888) 522-5372; fax (972) 910-8036; Internet: www.fairchildsemi.com.