MAX8535

ORing MOSFET Controllers with Fastest Fault Isolation for Redundant Power Supplies

Simplest, smallest OR-ing MOSFET Controllers with Fastest Reverse-Current Protection


Please check latest availability status for a specific part variant.

Description

Critical loads often employ parallel-connected power supplies with redundancy in order to enhance system reliability. The MAX8535/MAX8536/MAX8585 are highly integrated but inexpensive MOSFET controllers that provide isolation and redundant power capability in high-reliability systems. The MAX8535/MAX8585 are used in 12V systems, and have an internal charge pump to drive the gates of the n-channel pass elements to VCC + 10V. The MAX8536 is used in 3.3V and 5V systems, with a chargepump output of VCC + 5V.

During startup, the MAX8535/MAX8536/MAX8585 monitor the voltage drop across external MOSFETs. Once VCC approaches or exceeds the bus voltage, the MOSFETs are turned on. The MAX8535/MAX8536/MAX8585 feature a dual-purpose TIMER input. A single external resistor from TIMER to ground sets the turn-on speed of the external MOSFETs. Optionally, the TIMER input can be used as a logic-enable pin. Once the device is turned on, the MAX8535/MAX8536/MAX8585 monitor the load, protecting against overvoltage, undervoltage, and reverse-current conditions.

Overvoltage and undervoltage fault thresholds are adjustable and can be disabled. The current-limit trip points are set by the external MOSFETs' RDS(ON), reducing component count. An open-drain logic-low fault output indicates if an overvoltage, undervoltage, or reverse-current fault occurs.

All devices come in a space-saving 8-pin µMAX® package and are specified over the extended -40°C to +85°C temperature range.
MAX8535, MAX8536, MAX8585: Typical Operating Circuit MAX8535, MAX8536, MAX8585: Typical Operating Circuit Enlarge+

Key Features

  • Simple, Integrated, and Inexpensive ORing MOSFET Controller
  • ORing MOSFET Drive for 12V (MAX8535/MAX8585) and 3.3V or 5V (MAX8536) Bus
  • Eliminates ORing Diode Power Dissipation and Reverse Leakage Current
  • Provides N + 1 Redundant Supply Capability for Highly Reliable Systems
  • Isolates Failed Supply from Output Bus in <1µs
  • Reverse-Current Flow Detection
  • Programmable Soft-Start
  • Logic-Enable Input
  • Adjustable Overvoltage and Undervoltage Trip Points
  • Fault-Indicator Output
  • Space-Saving 8-Pin µMAX Package

Applications/Uses

  • Network/Telecom Power Supplies
  • On-Board Redundant Power Supplies in Blade Servers
  • Rectifiers
  • Redundant Power Supplies in High-Availability Systems
  • Silver Box Supplies for Servers
Part NumberReverse Current Protect.Under Voltage ProtectCharge Pump Cap.Soft StartEnableFault IndicatorPackage/PinsOper. Temp.
(°C)
Budgetary
Price
See Notes
MAX8535 YesYesYesYesYesYes
UMAX/8
-40 to +85$1.92 @1k
MAX8536 
UMAX/8
$2.63 @1k
See All ORing MOSFET Controllers (5)
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.


MAX8535EVKIT: Evaluation Kit for the MAX8535
MAX8536EVKIT: Evaluation Kit for the MAX8536

Quality and Environmental Data

Request Reliability Report for: MAX8535 
Lead-Free Package Tin (Sn) Whisker Reports
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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