Burning LTC4414

AElb said:

2. Is there maximum current for this configuration, I am planing to use it for 20A load.

For apps >10A, you should be using an NFET controller.
NFETs are cheaper, smaller, and have lower RDS(ON).
The inrush control method is also a lot easier.

Hi,

I understand it is better to use NFETs. However, this is our design for now. Can we improve it?

Can you pls answer on questions no.1 and especially no.3?

Thanks

AE

Hi,

For no.1 and no.3, At the design the connection is like this:

Do you see any problem with it that can explain burning of the IC?

Thanks

AE

If PFET fails, GATE can be shorted to VIN or VOUT. This can damage the IC.

Hi, 

Why should be problem to with the FET at high current, it has external FETs and all the current flow through the FETs?

In addition,

As I mentions above, the connection of the SENSE pin in my design is as in the drawing ( Sense is connected directly to the FET drain). At this design there isn't external power input and only direct battery 20V is connected in the Supply input. The CTL is the On/Off switch. Do you see ant problem with it?

Since I have several LTC4414 that were burned and doesn't function (the Gate pin is high constantly).

Can you suggest the reason for it?

Does it better to connect SENSE to GND at this configuration?

Thanks

AE

Hi,

Your support will be highly appricated...

Thanks

AE

Hi Ashapiro,

Thanks for your answers.

Can you please tell what is the reason the LTC4414 isn't good for >10A? The P-FET is external?

If i will use it to higher current, it may fail?

Thanks

AE