HIP6005B
Buck Pulse-Width Modulator (PWM) Controller and Output Voltage Monitor HIP6005B

Key Features

• Drives N-Channel MOSFET
• Operates from +5V or +12V Input
• Simple Single-Loop Control Design
• Voltage-Mode PWM Control
• Fast Transient Response
• High-Bandwidth Error Amplifier
• Full 0% to 100% Duty Ratio
• Excellent Output Voltage Regulation
• ±1% Over Line Voltage and Temperature
• TTL-Compatible 5-Bit Digital-to-Analog Output Voltage Selection
• Wide Range 1.3V_DC to 3.5V_DC
• 0.1V Binary Steps 2.1V_DC to 3.5V_DC
• 0.05V Binary Steps 1.3V_DC to 2.05V_DC
• Power-Good Output Voltage Monitor
• Over-Voltage and Over-Current Fault Monitors
• Does Not Require Extra Current Sensing Element, Uses MOSFET's r_DS(ON)
• Small Converter Size
• Constant Frequency Operation
• 200kHz Free-Running Oscillator Programmable from 50kHz to over 1MHz

Description

The HIP6005B provides complete control and protection for a DC-DC converter optimized for high-performance microprocessor applications. It is designed to drive an N-Channel MOSFET in a standard buck topology. The HIP6005B integrates all of the control, output adjustment, monitoring and protection functions into a single package.

The output voltage of the converter is easily adjusted and precisely regulated. The HIP6005B includes a fully TTL-compatible 5-input digital-to-analog converter (DAC) that adjusts the output voltage from 1.3V_DC to 2.05V_DC in 0.05V increments and from 2.1V_DC to 3.5V_DC in 0.1V steps. The precision reference and voltage-mode regulator hold the selected output voltage to within ±1% over temperature and line voltage variations.

The HIP6005B provides simple, single feedback loop, voltagemode control with fast transient response. It includes a 200kHz free-running triangle-wave oscillator that is adjustable from below 50kHz to over 1MHz. The error amplifier features a 15MHz gain-bandwidth product and 6V/µs slew rate which enables high converter bandwidth for fast transient performance. The resulting PWM duty ratio ranges from 0% to 100%.

The HIP6005B monitors the output voltage with a window comparator that tracks the DAC output and issues a Power Good signal when the output is within ±10%. The HIP6005B protects against over-current and over-voltage conditions by inhibiting PWM operation. Additional built-in over-voltage protection triggers an external SCR to crowbar the input supply. The HIP6005B monitors the current by using the r_DS(ON) of the upper MOSFET which eliminates the need for a current sensing resistor.

Applications

• Power Supply for Pentium®, Pentium Pro, Pentium II, PowerPC™, K6™, 6X86™ and Alpha™ Microprocessors
• High-Power 5V to 3.xV DC-DC Regulators
• Low-Voltage Distributed Power Supplies