1. Products
  2. Power Monitor, Control, and Protection
  3. Hot Swap Controllers
  4. High Voltage Hot Swap Controllers
  5. MAX5949


Features and Benefits

  • Allow Safe Board Insertion and Removal from a Live -48V Backplane
  • Pin and Function Compatible with LT4250L (MAX5949A)
  • Pin Compatible with LT1640L (MAX5949A)
  • Pin and Function Compatible with LT4250H (MAX5949B)
  • Pin Compatible with LT1640H (MAX5949B)
  • Circuit-Breaker Immunity to Input Voltage Steps and Current Spikes
  • Withstand -100V Input Transients with No External Components
  • Programmable Inrush and Short-Circuit Current Limits
  • Operate from -20V to -80V
  • Programmable Overvoltage Protection
  • Programmable Undervoltage Lockout
  • Power Up into a Shorted Load
  • Power-Good Control Output

Product Details

The MAX5949A/MAX5949B are hot-swap controllers that allow a circuit card to be safely hot plugged into a live backplane. The MAX5949A/MAX5949B operate from -20V to -80V and are well-suited for -48V power systems. These devices are pin and function compatible with the LT4250 and pin compatible with the LT1640.

The MAX5949A/MAX5949B provide a controlled turn-on to circuit cards preventing glitches on the power-supply rail and damage to board connectors and components. The MAX5949A/MAX5949B provide undervoltage, overvoltage, and overcurrent protection. These devices ensure the input voltage is stable and within tolerance before applying power to the load.

Both the MAX5949A and MAX5949B protect a system against overcurrent and short-circuit conditions by turning off the external MOSFET in the event of a fault condition. The MAX5949A/MAX5949B also provide protection against input voltage steps. During an input voltage step, the MAX5949A/MAX5949B limit the current drawn by the load to a safe level without turning off power to the load.

Both devices feature an open-drain power-good status output (PWRGD-bar for the MAX5949A or PWRGD for the MAX5949B) that can be used to enable downstream converters.

The MAX5949A/MAX5949B are available in an 8-pin SO package. Both devices are specified for the extended -40°C to +85°C temperature range.


  • -48V Distributed Power Systems
  • Base-Station Line Cards
  • Central-Office Line Cards
  • Central-Office Switching
  • Negative Power-Supply Controls
  • Network Routers and Switches
  • Server Line Cards
  • Telecom Line Cards

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Product Recommendations

MAX5949 Companion Parts

Recommended Related Parts

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
MAX5949AESA+ Material Declaration Reliability Data Small-Outline IC, Narrow (0.15in)
MAX5949AESA+T Material Declaration Reliability Data Small-Outline IC, Narrow (0.15in)
Wafer Fabrication Data

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