Top

High-Speed, Adjustable, Synchronous Step-Down Controllers with Integrated Voltage Positioning

Voltage-Positioned CPU Power Supply, Accurate Current Sense

Product Details

Key Features

Applications/Uses

Simplified Block Diagram

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 .

Key Features

  • High-Efficiency Voltage Positioning
  • Quick-PWM Architecture
  • ±1% VOUT Line-Regulation Accuracy
  • Adjustable Output Range (5-Bit DAC)
    • MAX1716: 0.925V to 1.6V
    • MAX1854: 0.925V to 2.0V
    • MAX1855: 0.600V to 1.75V
  • 2V to 28V Input Range
  • 200/300/400/550kHz Switching Frequency
  • Output Undervoltage Protection
  • Overvoltage Protection (MAX1716/MAX1855)
  • Drive Large Synchronous-Rectifier MOSFETs
  • 1.7ms Digital Soft-Start
  • 700µA ICC Supply Current
  • 1µA Shutdown Supply Current
  • 2V ±1% Reference Output
  • VGATE Transition-Complete Indicator
  • Small 24-Pin QSOP Package

Applications/Uses

  • Computers: Desktop, Workstation, Server
  • Notebook Computers
  • Servers
  • Workstations

Description

The MAX1716/MAX1854/MAX1855 step-down controllers are intended for core CPU DC-DC converters in notebook computers. They feature a dynamically adjustable output (5-bit DAC), ultra-fast transient response, high DC accuracy, and 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 MAX1716/MAX1854/MAX1855 are designed specifically for CPU core applications requiring a voltage-positioned supply. The voltage-positioning input (VPS), combined with a high DC accuracy control loop, is used to implement a power supply that modifies its output set point in response to the load current. This arrangement decreases full-load power dissipation and reduces the required number of output capacitors.

The 28V input range of the MAX1716/MAX1854/MAX1855 enables single-stage buck conversion from high-voltage batteries for the maximum possible efficiency. Alternatively, the devices' high-frequency capability combined with two-stage conversion (stepping down the +5V system supply instead of the battery) allows the smallest possible physical size. The output voltage can be dynamically adjusted through the 5-bit digital-to-analog converter (DAC) inputs.

The MAX1716/MAX1854/MAX1855 are available in a 24-pin QSOP package. For applications requiring SpeedStep® power control (see the MAX1717).

Simplified Block Diagram

MAX1716, MAX1854, MAX1855: Typical Operating Circuit MAX1716, MAX1854, MAX1855: Typical Operating Circuit 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 .