The IRU3018 controller IC is specifically designed to meet Intel specification for Pentium II microprocessor applications as well as the next generation of P6 family processors. The IRU3018 provides a single chip controller IC for the Vcore, LDO controller for GTL+ and an internal 200mA regulator for clock supply which are required for the Pentium II applications. These devices feature a patented topology that in combination with a few external components as shown in the typical application circuit, will provide in excess of 18A of output current for an onboard DC-DC converter while automatically providing the right output voltage via the 5-bit internal DAC. The IRU3018 also features loss-less current sensing for both switchers by using the RDS(on) of the high-side power MOSFET as the sensing resistor, internal current limiting for the clock supply, and a Power Good window comparator that switches its open collector output low when any one of the outputs is outside of a pre-programmed window. Other features of the device are: Under-voltage lockout for both 5V and 12V supplies, an external programmable soft-start function, programming the oscillator frequency via an external resistor, Over-Voltage Protection (OVP) circuitry for both switcher outputs and an internal thermal shutdown.