Datasheet LT4351 (Analog Devices)

ManufacturerAnalog Devices
DescriptionMOSFET Diode-OR Controller
Pages / Page20 / 1 — FEATURES. DESCRIPTION. Low Loss Replacement for ORing Diode in Multiple. …
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Document Languageenglish

FEATURES. DESCRIPTION. Low Loss Replacement for ORing Diode in Multiple. Sourced Power Supplies

Datasheet LT4351 Analog Devices

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LT4351 MOSFET Diode-OR Controller
FEATURES DESCRIPTION
n
Low Loss Replacement for ORing Diode in Multiple
The LT®4351 creates a near ideal diode using external
Sourced Power Supplies
single or back-to-back N-channel MOSFETs. This ideal n
External N-Channel MOSFETs for High Current
diode function permits low loss ORing of multiple power
Capability
sources. Power sources can easily be ORed together to n
Internal Boost Regulator Supply for MOSFET
increase total system power and reliability with minimal
Gate Drive
effect on supply voltage or efficiency. Disparate power n
Wide Input Range: 1.2V to 18V
supplies can be efficiently ORed together. n Fast Switching MOSFET Gate Control The IC monitors the input supply with respect to the load n Input Under and Overvoltage Detection and turns on the MOSFET(s) when the input supply is n STATUS and FAULT Outputs for Monitoring higher. If the MOSFET’s R n DS(ON) is sufficiently small, the Internal MOSFET Gate Clamp LT4351 will regulate the voltage across the MOSFET(s) n Available in a 10-pin MSOP Package to 15mV. A STATUS pin indicates the MOSFET on-state.
APPLICATIONS
An internal boost regulator generates the MOSFET gate n drive voltage. Low operating voltage allows for ORing of Paralleled Power Supplies n supplies as low as 1.2V. Uninterrupted Supplies n High Availability Systems The LT4351 will disable power passage during undervolt- n N + 1 Redundant Power Supplies age or overvoltage conditions. These voltages are set by L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks resistive dividers on the UV and OV pins. The undervoltage and PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. threshold has user programmable hysteresis. Overvoltage detection is filtered to reduce false triggering. The LT4351 is available in a 10-pin MSOP package.
TYPICAL APPLICATION Dual 5V Redundant Supply
Si4862DY Si4862DY POWER 5V 5V COMMON POWER 5V SUPPLY SUPPLY 1 10µF 2 1× 10µF C 4.7µH 1 LOAD LOAD × 1µF 1µF 4.7µH VIN GATE OUT OUT GATE VIN MBR0530 V MBR0530 DD VDD MBR0530 LT4351 LT4351 MBR0530 SW STATUS STATUS SW 24.9k 24.9k 1% UV 1% UV FAULT FAULT 232Ω 232Ω 1% 1% OV GND GND OV 1.47k 1.47k 1% 4351 TA01 1% 4351fd 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts