LTC4354 - Negative Voltage Diode-OR Controller and Monitor

Features

  • Controls N-Channel MOSFETs
  • Replaces Power Schottky Diodes
  • Less Than 1µs Turn-off Time Limits Peak Fault Current
  • 80V Operation
  • Smooth Switchover Without Oscillation
  • No Reverse DC Current
  • Fault Output
  • Selectable Fault Thresholds
  • Available in 8-Pin (3mm × 2mm) DFN and 8-Pin SO Packages

Typical Application

LTC4354 Typical Application
LTC4354 Typical Application

Description

The LTC4354 is a negative voltage diode-OR controller that drives two external N-channel MOSFETs. It replaces two Schottky diodes and the associated heatsink, saving power and area. The power dissipation is greatly reduced by using N-channel MOSFETs as the pass transistors. Power sources can easily be ORed together to increase total system power and reliability.

When first powered up, the MOSFET body diode conducts the load current until the pass transistor is turned on. The LTC4354 servos the voltage drop across the pass transistors to ensure smooth transfer of current from one transistor to the other without oscillation.

The MOSFETs are turned off in less than 1µs whenever the corresponding power source fails or is shorted. Fast turnoff prevents the reverse current from reaching a level that could damage the pass transistors.

A fault detection circuit with an open drain output capable of driving an LED or opto-coupler indicates either MOSFET short, MOSFET open or supply failed.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC4354CDDB#PBF 3x2 DFN-8 DDB C 05-08-1702 Yes
LTC4354CDDB#TRMPBF 3x2 DFN-8 DDB C 05-08-1702 Yes
LTC4354CDDB#TRPBF 3x2 DFN-8 DDB C 05-08-1702 Yes
LTC4354CS8#PBF SO-8 S8 C 05-08-1610 (S8) Yes
LTC4354CS8#TRPBF SO-8 S8 C 05-08-1610 (S8) Yes
LTC4354IDDB#PBF 3x2 DFN-8 DDB I 05-08-1702 Yes
LTC4354IDDB#TRMPBF 3x2 DFN-8 DDB I 05-08-1702 Yes
LTC4354IDDB#TRPBF 3x2 DFN-8 DDB I 05-08-1702 Yes
LTC4354IS8#PBF SO-8 S8 I 05-08-1610 (S8) Yes
LTC4354IS8#TRPBF SO-8 S8 I 05-08-1610 (S8) Yes


LTC4354 Package Drawing
LTC4354 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC4354CDDB#PBF 3x2 DFN-8 C $2.73 Yes
LTC4354CDDB#TRMPBF 3x2 DFN-8 C $2.73 $2.13 Yes
LTC4354CDDB#TRPBF 3x2 DFN-8 C $2.73 $2.11 Yes
LTC4354CS8#PBF SO-8 C $2.60 $1.95 Yes
LTC4354CS8#TRPBF SO-8 C $2.01 Yes
LTC4354IDDB#PBF 3x2 DFN-8 I $3.33 Yes
LTC4354IDDB#TRMPBF 3x2 DFN-8 I $3.33 $2.53 Yes
LTC4354IDDB#TRPBF 3x2 DFN-8 I $3.33 $2.51 Yes
LTC4354IS8#PBF SO-8 I $3.10 $2.35 Yes
LTC4354IS8#TRPBF SO-8 I $2.41 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC852A LTC4354 Negative Voltage Diode-OR Controller and Monitor $50.00
Buy Now
Click here to view our complete list of demo boards

Applications

  • AdvancedTCA Systems
  • –48V Distributed Power Systems
  • Computer Systems/Servers
  • Telecom Infrastructure
  • Optical Networks

Product Notifications

Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.

Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.

Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

Models for the following parts are available in LTspice:
LTC4354

Technical Support