MAX8555AEUB ,Low-Cost, High-Reliability, 0.5V to 3.3V ORing MOSFET ControllersFeaturesCritical loads often employ parallel-connected power♦ Simple, Integrated, and Inexpensive M ..
MAX8555AEUB ,Low-Cost, High-Reliability, 0.5V to 3.3V ORing MOSFET ControllersApplications*Exposed paddlePoint-of-Load SuppliesPin ConfigurationsPower-Supply ModulesServersTOP V ..
MAX8555AEUB+ ,Low-Cost, High-Reliability, 0.5V to 3.3V ORing MOSFET ControllersFeaturesCritical loads often employ parallel-connected power♦ Simple, Integrated, and Inexpensive M ..
MAX8556ETE ,PLASTIC ENCAPSULATED DEVICESTable of Contents I. ........Device Description V. ........Quality Assurance Information II ..
MAX8556ETE ,PLASTIC ENCAPSULATED DEVICESApplicationsServers and Storage DevicesPIN-PART TEMP RANGE FEATURENetworkingPACKAGE16 Thin QFNBase ..
MAX8556ETE+ ,4A Ultra-Low-Input-Voltage LDO RegulatorsMAX8556/MAX855719-3257; Rev 2; 8/094A Ultra-Low-Input-VoltageLDO Regulators
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY
MB82D01171A-80LLPBN , 16 Mbit (1 M word x 16 bit) Mobile Phone Application Specific Memory
MB82D01171A-80LLPBN , 16 Mbit (1 M word x 16 bit) Mobile Phone Application Specific Memory
MB82D01171A-90LLPBT , 16 Mbit (1 M word x 16 bit) Mobile Phone Application Specific Memory
MB82D01171A-90LLPBT , 16 Mbit (1 M word x 16 bit) Mobile Phone Application Specific Memory
MAX8555AEUB
Low-Cost, High-Reliability, 0.5V to 3.3V ORing MOSFET Controllers
General DescriptionCritical loads often employ parallel-connected power
supplies with redundancy to enhance system reliability.
The MAX8555/MAX8555A are highly integrated, inex-
pensive MOSFET controllers that provide isolation and
redundant power capability in high-reliability systems.
The MAX8555/MAX8555A are used in 0.5V to 3.3V sys-
tems, and have an internal charge pump to drive the
gates of the N-channel pass elements to (VCS++ 5V).
During startup, the MAX8555/MAX8555A monitor the
voltage drop across the external MOSFETs. Once VCS+
approaches or exceeds the bus voltage (VCS-), the
MOSFETs are turned on. The MAX8555/MAX8555A fea-
ture 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 input. Once the external
MOSFET is turned on, these controllers monitor the
load, protecting the bus against overvoltage, undervolt-
age, and reverse-current fault conditions. The
MAX8555 is available with a 40mV reverse-current
threshold, while the MAX8555A is available with a 20mV
reverse-current threshold.
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. The MAX8555 and the
MAX8555A can shut down in response to a reverse-
current fault condition as quickly as 200ns.
Both devices come in space-saving 10-pin µMAX or
TDFN packages and are specified over the extended
-40°C to +85°C temperature range.
ApplicationsPoint-of-Load Supplies
Power-Supply Modules
Servers
Telecom Power Supplies
Rectifiers
Redundant Power Supplies in High-Availability
Systems
FeaturesSimple, Integrated, and Inexpensive MOSFET
ControllersORing FET Drive for 0.5V to 3.3VEliminate ORing Diode Power DissipationProvide N+1 Redundant Supply Capability for
Highly Reliable SystemsIsolate Failed Short-Circuit Supply from
Output BUSRespond to Reverse Short-Circuit Current
in 200nsAdjustable Blank TimeProgrammable Soft-StartLogic Enable InputAdjustable Overvoltage and Undervoltage
Trip PointsFault-Indicator OutputSpace-Saving Packages
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET Controllers
Ordering Information13-3087; Rev 0; 1/04
Pin Configurations*Exposed paddle
Typical Operating Circuit appears at end of data sheet.
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET Controllers
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VDD = 12V, VCS-= 1.4V, VCS+ = 1.5V, RTIMER = 25kΩ, VUVP= 1V, VOVP= 0.25V, RFAULT = 50kΩ, CVDD = CGATE= CVL = 0.01µF,
TA = 0°C to +85°C, unless otherwise noted.)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
GATE to GND.........................................................-0.3V to +12V
FAULT, VL to GND...................................................-0.3V to +6V
OVP, UVP, TIMER, CS+, CS- to GND.......-0.3V to +(VVL+ 0.3V)
VDDto GND..................................................(VVL- 0.3V) to +18V
Continuous Power Dissipation (TA= +70°C)
10-Pin µMAX (derate 5.6mW/°C above +70°C)...........444mW
10-Pin TDFN (derate 24.4mW/°C above +70°C).......1951mW
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET Controllers
ELECTRICAL CHARACTERISTICS (continued)(VDD = 12V, VCS-= 1.4V, VCS+ = 1.5V, RTIMER = 25kΩ, VUVP= 1V, VOVP= 0.25V, RFAULT = 50kΩ, CVDD = CGATE= CVL = 0.01µF,
TA = 0°C to +85°C, unless otherwise noted.)
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET Controllers
ELECTRICAL CHARACTERISTICS (continued)(VDD = 12V, VCS-= 1.4V, VCS+ = 1.5V, RTIMER = 25kΩ, VUVP= 1V, VOVP= 0.25V, RFAULT = 50kΩ, CVDD = CGATE= CVL = 0.01µF,
TA = 0°C to +85°C, unless otherwise noted.)
ELECTRICAL CHARACTERISTICS (VDD = 12V, VCS-= 1.4V, VCS+ = 1.5V, RTIMER = 25kΩ, VUVP= 1V, VOVP= 0.25V, RFAULT = 50kΩ, CVDD = CGATE= CVL = 0.01µF,
TA = -40°C to +85°C, unless otherwise noted.) (Note 3)
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET Controllers
Note 2:Gate shutdown delay is measured from reverse-current fault to the start of gate-voltage falling or from TIMER to the start of
gate-voltage falling.
Note 3:Specifications to -40°C are guaranteed by design and not production tested.
ELECTRICAL CHARACTERISTICS (continued)(VDD = 12V, VCS-= 1.4V, VCS+ = 1.5V, RTIMER = 25kΩ, VUVP= 1V, VOVP= 0.25V, RFAULT = 50kΩ, CVDD = CGATE= CVL = 0.01µF,
TA = -40°C to +85°C, unless otherwise noted.) (Note 3)
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET Controllers
Typical Operating Characteristics(VDD = 12V, VCS+= 1.5V, RTIMER = 25kΩ, VUVP= 1V, VOVP= 0.4V, RFAULT = 50kΩto output bus, CVDD = CGATE= CVL= 0.01µF, TA =
+25°C, R1 = 2Ωin Figure 3, MAX8555A, unless otherwise noted.)
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET Controllersypical Operating Characteristics (continued)(VDD = 12V, VCS+= 1.5V, RTIMER = 25kΩ, VUVP= 1V, VOVP= 0.4V, RFAULT = 50kΩto output bus, CVDD = CGATE= CVL= 0.01µF, TA =
+25°C, R1 = 2Ωin Figure 3, MAX8555A, unless otherwise noted.)
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET Controllers
Pin Description
MAX8555/MAX8555A
Low-Cost, High-Reliability, 0.5V to 3.3V ORing
MOSFET ControllersFigure 1. MAX8555/MAX8555A Functional Diagram
