General Description

The MAX17480 is a triple-output, step-down, fixed frequency controller for AMD’s serial VID interface (SVI) CPU and northbridge (NB) core supplies. The MAX17480 consists of two high-current SMPSs for the CPU cores and one 4A internal switch SMPS for the NB core. The two CPU core SMPSs run 180° out-of-phase for true interleaved operation, minimizing input capacitance. The 4A internal switch SMPS runs at twice the switching frequency of the core SMPS, reducing the size of the external components.

The MAX17480 is fully AMD SVI compliant. Output voltages are dynamically changed through a 2-wire SVI,allowing the SMPSs to be individually programmed to different voltages. A slew-rate controller allows controlled transitions between VID codes and controlled soft-start. SVI also allows each SMPS to be individually set into a low-power pulse-skipping state.

Features

♦ Dual-Output Fixed-Frequency Core Supply Controller

   Split or Combinable Outputs Detected at Power-Up

   Dynamic Phase Selection Optimizes

   Active/Sleep Efficiency

   Transient Phase Repeat Reduces Output Capacitance

   True Out-of-Phase Operation Reduces Input Capacitance

   Programmable AC and DC Droop

   Accurate Current Balance and Current Limit

   Integrated Drivers for Large Synchronous

   Rectifier MOSFETs

   Programmable 100kHz to 600kHz Switching Frequency

   4V to 26V Battery Input Voltage Range

♦ 4A Internal Switch Northbridge SMPS

   2.7V to 5.5V Input Voltage Range

   2x Programmable Switching Frequency

   75mΩ/40mΩPower Switches

♦ ±0.5 VOUTAccuracy over Line, Load, and

   Temperature

♦ AMD SVI-Compliant Serial Interface with

   Switchable Address

♦ 7-Bit On-Board DAC: 0 to +1.550V Output Adjust Range

♦ Integrated Boost Switches

♦ Adjustable Slew-Rate Control

♦ Power-Good (PWRGD) and Thermal-Fault

   (VRHOT) Outputs

♦ System Power-OK (PGD_IN) Input

♦ Overvoltage, Undervoltage, and Thermal-Fault

   Protection

♦ Voltage Soft-Startup and Passive Shutdown

♦

Applications

   Mobile AMD SVI Core Supplies

   Multiphase CPU Core Supplies

   Voltage-Positioned, Step-Down Converters

   Notebook/Desktop Computers