PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller

Power Supply/Thermal Manager Provides Unparalleled “Black Box” Failure Logging and Energy Efficient Fan Control

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The MAX34441 is a complex system monitor that can manage up to five power supplies and a fan. The power-supply manager monitors the power-supply output voltage and constantly checks for user-programmable overvoltage and undervoltage thresholds. It can also margin the power-supply output voltage up or down to a user-programmable level. The margining is performed in a closed-loop arrangement whereby the device automatically adjusts a pulse-width-modulated (PWM) output and then measures the resultant output voltage. The power-supply manager can also sequence the supplies in any order at both power-up and power-down. With the addition of an external current-sense amplifier, the device can also monitor currents.

The device also contains closed-loop fan-speed control. Based on user-programmable settings for fan-control PWM duty cycles or RPM speeds at particular temperature breakpoints, the device automatically adjusts the fan speed in a manner to reduce audible noise and power consumption.

MAX34441: Typical Operating Circuit MAX34441: Typical Operating Circuit Enlarge+

Key Features

  • 5 Channels of Power-Supply Management
    • Voltage Measurement/Monitoring
      • Differential 12-Bit 1% Accurate ADC
      • Min/Max Threshold Excursion Detection
    • Supports Current Monitoring with External Current-Sense Amplifier
    • Automatic Closed-Loop Margining
    • Programmable Up and Down Sequencing
    • Power-Good Output
  • 1 Channel of Fan Control
    • Supports 3-Wire and 4-Wire Fans
    • Automatic Closed-Loop Fan-Speed Control
    • Support for Dual Tachometer Fans
    • Fan-Fault Detection
  • Supports Up to Six Temperature Sensors
    • External Thermal Diode Interface with Automatic Series Resistance Cancellation
    • One Internal Temperature Sensor
    • Support for Up to Four Additional I²C Digital Temp Sensor ICs
    • Fault Detection on All Temp Sensors
  • PMBus™-Compliant Command Interface
  • I²C/SMBus™-Compatible Serial Bus with Bus Timeout Function
  • On-Board Nonvolatile Fault Logging and Default Configuration Setting
  • No External Clocking Required
  • +3.3V Supply Voltage


  • Base Stations
  • Industrial Controls
  • Network Switches/Routers
  • Servers
  • Smart Grid Network Systems

See parametric specs for Power-Supply Sequencers and Voltage Trackers (44)

Part NumberOptionInterfaceInput Chan.VIN
Oper. Temp.
maxSee Notes
53.3-40 to +85
$3.72 @1k

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX34441EVKIT: Evaluation Kit for the MAX34440 and MAX34441
Product Reliability Reports: MAX34441.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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