HIP6021A

Features:

• Provides 4 Regulated Voltages
        - Microprocessor Core, AGP Bus, Memory, and GTL Bus Power
• Drives N-Channel MOSFETs
• Linear Regulator Drives Compatible with both MOSFET and Bipolar Series Pass Transistors
• Fixed or Externally Resistor-Adjustable Linear Outputs
• Simple Single-Loop Control Design
        - Voltage-Mode PWM Control
• Fast PWM Converter Transient Response
        - High-Bandwidth Error Amplifier
        - Full 0% to 100% Duty Ratio
• Excellent Output Voltage Regulation
        - Core PWM Output: ±1% Over Temperature
        - Other Outputs: ±3% Over Temperature
• TTL-Compatible 5-Bit DAC Core Output Voltage Selection
        - Shutdown Feature Removed When All Inputs High
        - Wide Range 1.3VDC to 3.5VDC
• Power-Good Output Voltage Monitor
• Over-Voltage and Over-Current Fault Monitors
        - Switching Regulator Does Not Require Extra Current Sensing Element, Uses Upper MOSFET's rDS(ON)
• Small Converter Size
        - Constant Frequency Operation
        - 200kHz Free-Running Oscillator; Programmable From 50kHz to Over 1MHz
        - Small External Component Count


Application

• Motherboard Power Regulation for Computers


Pinout




Specifications

Supply Voltage, V_CC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +15V
PGOOD, RT/FAULT, DRIVE, PHASE,
and GATE Voltage . . . . . . . . . . . . . . . GND - 0.3V to V_CC + 0.3V
Input, Output or I/O Voltage . . . . . . . . .  . .  . . GND -0.3V to 7V
ESD Classification . . . . . . . . . . . . . . . . . . . . .  . . . . . . . . Class 1


Description

The HIP6021A provides the power control and protection for four output voltages in high-performance, graphics intensive microprocessor and computer applications. The HIP6021A IC integrates a voltage-mode PWM controller and three linear controllers, as well as the monitoring and protection functions into a 28 lead SOIC package.

The HIP6021A synchronous-rectified buck converter includes an Intelcompatible, TTL 5-input digital-to-analog converter (DAC) that adjusts the core PWM output voltage from 1.3VDC to 2.05VDC in 0.05V steps and from 2.1VDC to 3.5VDC in 0.1V increments. The precision reference and voltage-mode control provide ±1% static regulation. A TTL-compatible signal applied to the SELECT pin dictates which method of control is used for the AGP bus power: a low state results in linear control of the AGP bus to 1.5V, while a high state transitions the output through a linearly controlled softstart to 3.3V, followed by full enhancement of the external MOSFET to pass the input voltage. The other two linear regulators provide fixed output voltages of 1.5V GTL bus power and 1.8V power for the North/South Bridge core and/or cache memory. These levels are user-adjustable by means of an external resistor divider and pulling the FIX pin low. All linear controllers can employ either N-Channel MOSFETs or bipolar NPNs for the pass transistor.

The HIP6021A monitors all the output voltages. A single Power Good signal is issued when the core is within ±10% of the DAC setting and all other outputs are above their undervoltage levels. Additional built-in over-voltage protection for the core output uses the lower MOSFET to prevent output voltages above 115% of the DAC setting. The PWM controller's over-current function monitors the output current by using the voltage drop across the upper MOSFET's rDS(ON).