Features and Benefits
- 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
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.
- AdvancedTCA Systems
- –48V Distributed Power Systems
- Computer Systems/Servers
- Telecom Infrastructure
- Optical Networks
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
LTC4354 Companion Parts
Recommended Related Parts
Technical Articles (5)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.