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Dynamically Adjustable 6-Bit VID Step-Down Controller

Dynamically Adjustable, 6-Bit, VID-Compliant, Step-Down Controller for Notebook CPUs

Product Details

Key Features

Simplified Block Diagram

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Key Features

  • Quick-PWM Architecture
  • ±1% VOUT Accuracy Over Line and Load
  • 6-Bit On-Board DAC with Input Muxes
  • Precision-Adjustable VOUT Slew Control
  • 0.275V to 1.850V Output Adjust Range
  • Remote Feedback and Ground Sense
  • Supports Voltage-Positioned Applications
  • 2V to 28V Battery Input Range
  • 200kHz/300kHz/550kHz/1000kHz Switching Frequency
  • Over/Undervoltage Protection
  • Drives Large Synchronous-Rectifier FETs
  • 800µA (typ) ICC Supply Current
  • 10µA (typ) Shutdown Supply Current
  • 2V ±0.75% Reference Output
  • PGOOD Blanking During Transition

Applications/Uses

  • CPU Core Supply Converters
  • GPU Core Supply Converters
  • Notebook and Subnotebook Computers

Description

The MAX8720 step-down controller is intended for core CPU DC-DC converters in notebook computers. It features a dynamically adjustable output, ultra-fast transient response, high DC accuracy, and the high efficiency needed for leading-edge CPU core power supplies. Maxim's proprietary Quick-PWM™ quick-response, constant-on-time, PWM control scheme handles wide input/output voltage ratios with ease and provides 100ns "instant-on" response to load transients while maintaining a relatively constant switching frequency.

The output voltage can be dynamically adjusted through the 6-bit digital-to-analog converter (DAC) over a 0.275V to 1.850V range in 25mV steps. The MAX8720 has independent four-level logic inputs for setting the suspend voltage (S0–S1). Precision slew-rate control provides "just-in-time" arrival at the new DAC setting, minimizing surge currents to and from the battery. The internal DAC of the MAX8720 is synchronized to the slew-rate clock for improved operation under aggressive power management of newer chipsets and operating systems that can make incomplete mode transitions. Remote feedback and ground-sense inputs allow easy compensation for IR drops in PC board traces.

Single-stage buck conversion allows these devices to directly step down high-voltage batteries for the highest possible efficiency. Alternatively, two-stage conversion (stepping down the 5V system supply instead of the battery) at a higher switching frequency allows the minimum possible physical size.

The MAX8720 is available in a 28-pin QSOP or 36-pin 6mm x 6mm thin QFN package.

Simplified Block Diagram

MAX8720: Block Diagram MAX8720: Block Diagram Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .