MAX5955:Low-Voltage, Dual Hot-Swap Controllers with Independent On/Off Control

The MAX5955 and MAX5956 are +1V to +13.2V dual hot-swap controllers with independent on/off control for complete protection of dual-supply systems. They allow the safe insertion and removal of circuit cards into live backplanes. The MAX5955 and MAX5956 operate down to 1V provided one of the inputs is above 2.7V. 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 MAX5955 and MAX5956 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 completed, two on-chip comparators provide VariableSpeed/BiLevel™ protection against short-circuit and overcurrent faults, as well as immunity against system noise and load transients. In the event of a fault condition, the load is disconnected. The MAX5955B and MAX5956B must be unlatched after a fault, and the MAX5955A and MAX5956A automatically restart after a fault. The MAX5955 and MAX5956 integrate an on-board charge pump to drive the gates of low-cost, external n-channel MOSFETs. The devices offer integrated features like startup current regulation and current glitch protection to eliminate external timing resistors and capacitors. These devices provide open-drain status outputs, an adjustable startup timer, and adjustable current limits. The MAX5955 provides output undervoltage/ overvoltage protection for each channel, while the MAX5956 provides undervoltage/overvoltage monitoring for each channel. The MAX5955 and MAX5956 are available in a space-saving 16-pin QSOP package.

Key Features
  • Safe Hot Swap for +1V to +13.2V Power Supplies with VIN1 or VIN2 > 2.7V
  • Independent On/Off Control for Each Channel
  • Internal Charge Pumps Generate n-Channel MOSFET Gate Drives
  • Inrush Current Regulated at Startup
  • Circuit-Breaker Function
  • Adjustable Circuit Breaker/Current-Limit Threshold from 25mV to 100mV
  • VariableSpeed/BiLevel Circuit Breaker Response
  • Autoretry or Latched Fault Management
  • Status Outputs Indicate Fault/Safe Condition
  • Output Undervoltage and Overvoltage Monitoring or Protection
MAX5955, MAX5956: Typical Operating Circuit
MAX5955, MAX5956: Typical Operating Circuit
Applications/Uses
  • Base Station Line Cards
  • Hot Plug-In Daughter Cards
  • Network Switches, Routers, Hubs
  • Portable Computer Device Bays (Docking Stations)
  • Power-Supply Sequencing
  • RAID
  • Solid-State Circuit Breakers
DataSheet
titleDownload file
MAX5955-MAX5956 Data SheetMAX5955-MAX5956.pdf
Parametrics
Part NumberVIN
(V)
VIN
(V)
Circuit Breaker/ Current LimitCircuit Breaker/Current Limit Threshold
(mV)
Fault Condition ControlChannelsPositive/Negative RailFeaturesPackage/PinsBudgetary
Price
minmaxSee Notes
MAX5955113.2Current Limit25Latched Off
Periodic Retry
2PositiveUndervoltage/Overvoltage ProtectionQSOP/16$4.66 @1k
MAX5956Requires No RSENSEQSOP/16$4.18 @1k
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX5955AEEENo Longer AvailableMAX5955AEEE+QSOP,;16 pin;30.9 mm²-40°C to +85°CNo
MAX5955AEEE+ActiveQSOP,;16 pin;30.9 mm²-40°C to +85°CLead Free
MAX5955AEEE+TActiveQSOP,;16 pin;30.9 mm²-40°C to +85°CLead Free
MAX5955AEEE-TNo Longer AvailableMAX5955AEEE+TQSOP,;16 pin;30.9 mm²-40°C to +85°CNo
MAX5955AUEENo Longer AvailableMAX5955AUEE+QSOP,;16 pin;30.9 mm²0°C to +85°CNo
MAX5955AUEE+ActiveQSOP,;16 pin;30.9 mm²0°C to +85°CLead Free
MAX5955AUEE+TActiveQSOP,;16 pin;30.9 mm²0°C to +85°CLead Free
MAX5955AUEE-TNo Longer AvailableMAX5955AUEE+TQSOP;16 pin0°C to +85°CSee data sheet
MAX5955BEEENo Longer AvailableMAX5955BEEE+QSOP,;16 pin;30.9 mm²-40°C to +85°CNo
MAX5955BEEE+ActiveQSOP,;16 pin;30.9 mm²-40°C to +85°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX5955BEEE+TActiveQSOP,;16 pin;30.9 mm²-40°C to +85°CLead Free
MAX5955BEEE-TNo Longer AvailableMAX5955BEEE+TQSOP,;16 pin;30.9 mm²-40°C to +85°CNo
MAX5955BUEENo Longer AvailableMAX5955BUEE+QSOP,;16 pin;30.9 mm²0°C to +85°CNo
MAX5955BUEE+ActiveQSOP,;16 pin;30.9 mm²0°C to +85°CLead Free
MAX5955BUEE+TActiveQSOP,;16 pin;30.9 mm²0°C to +85°CLead Free
MAX5955BUEE-TNo Longer AvailableMAX5955BUEE+TQSOP;16 pin0°C to +85°CSee data sheet
MAX5955-MAX5956.pdf MAX5956
MAX5955-MAX5956.pdf MAX5956