IRU3055

Data Sheet No. PD94262 IRU3055 5-BIT PROGRAMMABLE 3-PHASE SYNCHRONOUS BUCK CONTROLLER IC PRELIMINARY DATA SHEET TEST SPEC FEATURES Meets VRM 9.0 Specification 3-Phase Controller with On-Board MOSFET Driver On-Board DAC programs the output voltage from 1.075V to 1.850V Loss-less Short Circuit Protection Programmable Frequency Synchronous operation allows maximum efficiency Minimum Part Count Soft-Start Power Good Function Hiccup Mode Current Limit DESCRIPTION The IRU3055 is a 3-phase synchronous Buck controller which provides high performance DC to DC converter for high current applications. The IRU3055 controller IC is specifically designed to meet Intel and AMD specifications for the new microprocessor requiring low voltage and high current. The IRU3055 features under-voltage lockout for both 5V and 12V supplies, an external and programmable softstart function as well as programming the oscillator frequency by using an external resistor. APPLICATIONS Intel Pentium 4 and AMD K7 TYPICAL APPLICATION C1 1uF D1 C2 0.1uF Q1 IRF3704S C3 1uF L1 1uH C4 1000uF 12V VCH3 VCH12 5V C5 1uF Vcc V CL1 V CL23 HDrv1 R1 OCSet 2.2K C6 6x 1500uF L2 Ref LDrv1 Rt PGnd1/ OCGnd CS1 SS C9 1uF R3 47K C10 0.1uF D4 PGnd2 D3 CS2 D2 HDrv3 D1 D0 C12 22nF R6 Comp 27K CS3 Fb LDrv3 PGnd3 HDrv2 Q2 IRF3711S 1uH R2 1.5K C8 1uF 1.5V / 60A IRU3055 LDrv2 Q3 IRF3704S Q4 IRF3711S L3 1uH R4 1.5K C11 1uF Q5 IRF3704S Q6 IRF3711S L4 1uH R5 1.5K C13 1uF C14 8x 2700uF C7 100pF (Optional) Figure 1 -...