LM5050MK-1EVAL: Can I use this same design, but without the 100 Ohms between pin 1 and 6?

Hello Kari,

Thank you for the quick response, could you tell me why the spurious spikes that could occur be harmful to this device since it has such a high voltage rating?
I was looking at the LM5050MK-2 and it has the same block diagram as the LM5050MK-1, with the exception that instead of having a VS pin supplying the bias circuitry, it is internally connected to the OUT pin. Is there internals which protects the LM5050MK-2 from spurs?

Thank you,
Louie

Hello Louie,

One of the difference between LM5050-2 and LM5050-1 is the way charge pump operates. In LM5050-2 Charge pump runs from IN only and in LM5050-1 it can run from IN or OUT.

Spikes on IN and OUT pins can occur during load switching on/off. As such IN and OUT pins can handle these spikes.
However, we need to decouple the supply pin Vs from the spikes.

Additionally, if you are concerned about leakage from OUT to IN when the FET is off, then having a current limiting resistor from OUT to VS will help to limit the leakage current.

Do you see a concern in your application if there is a leakage current from OUT-VS-LM5050-IN?

Regards,
Kari.

Hello, 

I was looking through the datasheet, and it says this is only true if I am using a system with input less than 5V. 

Since my system will be 12V input, I should be able to short Output to VS, correct?

Thank you, 

Louie