LTC 4013 change mosfet diode against a schottky diode

Hi,

 

I use the demo circuit 2374B for battery charging in a larger constellation and manged to burn M2 during a overcurrent test. To make the charger more reliable I’m thinking of changing the mosfet M2 against a Schottky diode is this possible or will this cause problems for LTC4013?

  

Best regards

Lukas Rydén

  • 0
    •  Analog Employees 
    on Dec 13, 2019 10:41 PM 11 months ago

    Hi Lukas,

    This shouldn't cause any problems, but it will hurt efficiency. You also should not need to do this for reliability's sake. What is the concern?

    Regards,

    Zack

  • Hi Zack,

    I´m aware of the decline in efficiency. DC 2374B is a part of a 24/12 V system and I’ve used LTC4359 as an ideal diode to protect from surge currents.

    The graph shows current measured out from charger when a possible faulty overcurrent occurs on the 24 V side. The oscillations looks like it could be ringing from diode which I think causes M2 to short. The demo circuit 2374B has pretty weak mosfet´s maybe it would be sufficient to replace them with more powerful ones to withstand this type of faulty events.

    The negative current values is in the direction in to the charger from the battery.

  • 0
    •  Analog Employees 
    on Dec 16, 2019 7:16 PM 11 months ago in reply to lukas87

    Hi Lukas,

    The FETs should be sufficient to withstand the currents shown here. I'm not totally sure what this event is - what causes it / is it repeating?

    Anyway, replacing with a diode is just fine if you want to try that.

    Regards,

    Zack