Summary of Dual diode controller two high power Schottkys replaces
The LTC4353 is a dual ideal-diode controller that drives external N-channel MOSFETs to replace high-power Schottky diodes for low-loss supply ORing and holdup, providing regulated forward drop, fast (<1 µs) turn-on/turn-off, enable inputs, and MOSFET on-status outputs. It operates from 2.9V to 18V (with optional VCC supply if both inputs are below 2.9V) and comes in 16-lead MSOP and 4mm × 3mm DFN packages.
Parts used in the LTC4353 Dual Diode Controller Project:
- LTC4353 dual diode controller IC
- External N-channel MOSFETs (two)
- VCC supply (external, if both inputs below 2.9V)
- Supply rails (0V to 18V inputs)
- Enable input connections
- MOSFET gate drive connections
- Status output monitoring connections
- 16-lead MSOP or DFN (4mm × 3mm) package footprint
Description
The LTC®4353 controls external N-channel MOSFETs to implement an ideal diode function. It replaces two high power Schottky diodes and their associated heat sinks, saving power and board area. The ideal diode function permits low loss power supply ORing and supply holdup applications.
The LTC4353 regulates the forward-voltage drop across the MOSFET to ensure smooth current transfer in diode-OR applications. A fast turn-on reduces the load voltage droop during supply switchover. If the input supply fails or is shorted, a fast turn-off minimizes reverse-current transients.
The controller operates with supplies from 2.9V to 18V. If both supplies are below 2.9V, an external supply is needed at the VCC pin. Enable inputs can be used to turn off the MOSFET and put the controller in a low current state. Status outputs indicate whether the MOSFETs are on or off.
Features
- Low Loss Replacement for Power Diodes
- Controls N-Channel MOSFETs
- 0V to 18V Supply ORing or Holdup
- 1μs Gate Turn-On and Turn-Off Time
- Enable Inputs
- MOSFET On-Status Outputs
- 16-Lead MSOP and DFN (4mm × 3mm) Packages
Linear Technology’s LTC4353 is a 0V to 18V dual diode controller that is designed to replace two high power Schottky diodes to provide low loss ORing of multiple power sources with minimal disturbance to supply voltages.
The device regulates the forward voltage drop across external N-channel mosfets to ensure smooth current transfer between supplies in diode-OR applications.
In low voltage systems, a slow handoff between controllers results in a voltage droop during supply switchover.
The turn on time is less than 1µs.
In the event the input supply fails or is shorted, a fast turn-off minimises reverse current.
The LTC4353 provides individual enable inputs that can be used to ensure priority to the main supply when supply voltages are within a mosfet body diode drop of each other.
For more read: Dual diode controller two high power Schottkys replaces
- What does the LTC4353 replace?
The LTC4353 replaces two high power Schottky diodes and their associated heat sinks to provide a low loss ideal diode function. - What type of MOSFETs does the LTC4353 control?
The LTC4353 controls external N-channel MOSFETs. - What supply voltage range does the LTC4353 operate over?
The controller operates with supplies from 2.9V to 18V. - Is an external VCC supply ever required?
Yes, if both supplies are below 2.9V an external supply is needed at the VCC pin. - How fast does the LTC4353 turn MOSFETs on and off?
Gate turn-on and turn-off times are 1 microsecond. - Does the LTC4353 provide enable inputs?
Yes, individual enable inputs can be used to turn off the MOSFET and put the controller in a low current state. - Are there status outputs on the LTC4353?
Yes, MOSFET on-status outputs indicate whether the MOSFETs are on or off. - What packages is the LTC4353 available in?
The LTC4353 is available in a 16-lead MSOP and a DFN (4mm × 3mm) package.
