Low-Voltage, Quad, Hot-Swap Controllers/Power Sequencers

Triple/Quad Hot-Swap Controllers Enable Sequencing, Tracking, or Independent On/Off Control for Low-Voltage Supplies

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The MAX5927/MAX5929 +1V to +13.2V quad hot-swap controllers provide complete protection for multisupply systems. They allow the safe insertion and removal of circuit cards into live backplanes. These devices hot swap multiple supplies ranging from +1V to +13.2V, provided one supply is at or above +2.7V and only one supply is above +11.0V. The input voltage rails (channels) can be configured to sequentially turn-on/off, track each other, or have completely independent operation.

The discharged filter capacitors of the circuit card provide low impedance to the live backplane. High inrush currents from the backplane to the circuit card can burn up connectors and components, or momentarily collapse the backplane power supply leading to a system reset. The MAX5927/MAX5929 hot-swap controllers prevent such problems by gradually ramping up the output voltage and regulating the current to a preset limit when the board is plugged in, allowing the system to stabilize safely. After the startup cycle is complete, on-chip comparators provide VariableSpeed/BiLevel™ protection against short-circuit and overcurrent faults, and provide immunity against system noise and load transients. The load is disconnected in the event of a fault condition. The MAX5929A automatically restarts after a fault condition, while the MAX5929L must be unlatched. The MAX5927 fault management mode is selectable.

The MAX5927/MAX5929 offer a variety of options to reduce external component count and design time. All devices integrate an on-board charge pump to drive the gates of low-cost external N-channel MOSFETs, an adjustable startup timer, and an adjustable current limit. The devices offer integrated features like startup current regulation and current glitch protection to eliminate external timing resistors and capacitors. The MAX5929_L provides an open-drain active-low status output for each channel, the MAX5929_H provides an open-drain active-high status output for each channel, and the MAX5927 status output polarity is selectable.

The MAX5927 is available in a 32-pin thin QFN package and the MAX5929 is available in a 24-pin QSOP package. All devices are specified over the extended temperature range, -40°C to +85°C.
MAX5927, MAX5929: Typical Operating Circuit MAX5927, MAX5929: Typical Operating Circuit Enlarge+

Key Features

  • Safe Hot Swap for +1V to +13.2V Power Supplies with Any Input Voltage (VIN_ > 2.7V and Only One VIN_ > 11.0V)
  • Adjustable Circuit Breaker/Current-Limit Threshold from 25mV to 100mV
  • Configurable Tracking, Sequencing, or Independent Operation Modes
  • VariableSpeed/BiLevel Circuit-Breaker Response
  • Internal Charge Pumps Generate N-Channel MOSFET Gate Drives
  • Inrush Current Regulated at Startup
  • Autoretry or Latched Fault Management
  • Programmable Undervoltage Lockout
  • Status Outputs Indicate Fault/Safe Condition


  • Base-Station Line Cards
  • Bays (Docking Stations)
  • Hot Plug-In Daughter Cards
  • Hubs
  • Network Routers and Switches
  • PCI Express® Hot Plug
  • Portable Computer Device
  • Power-Supply
  • RAID
  • Sequencing/Tracking
Part NumberVIN
Circuit Breaker/ Current LimitCircuit Breaker/Current Limit Threshold
Fault Condition ControlChannelsPositive/Negative RailPackage/Pins
MAX5927 113.2Current Limit25Programmable4Positive
See All Hot Swap Controllers (49)
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.

Technical Documents

Reference Schematic 4228 A Five-Channel (Three +V and Two -V) Hot-Swap Reference Design
Tutorial 2158 Advantages of IC-Based Hot-Swap Circuit Protection

Quality and Environmental Data

Product Reliability Reports: MAX5927.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

CAD Symbols and Footprints

  • MAX5927AETJ+
  • MAX5927AETJ+T
  • MAX5927ETJ+
  • MAX5927ETJ+T
  • Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

    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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