LTC3892 gate drive

I am finding that the LTC3892 appears to be having the high side gate drivers getting killed.  I looked through the datasheet and it does not indicate the drive current that the high side gate drive can source.  

What is the maximum  and continuous gate drive current that the LTC3892 can source?  

Note I find that the chip seems to fail when a load is attached to the output, what I assume happens is the output voltage drops and the high side FETs turn on for longer time and this causes more power to dissipated in the gate driver until it over heats and dies. 

  • 0
    •  Analog Employees 
    on Sep 4, 2018 9:23 PM

    trampas

    What company do you work for and what's Estimated Annual Usage of this project?

    Once charged, the MOSFET' gate doesn't take current to keep MOSFET' channel enhanced. It's should be a different cause of the failure in your case. It may be a good idea to contact local ADI representative for support. 

  • The usage is most likely around 50k per year.  We have had lots of problems with the LTC power chips and may have to design it out.. 

    The issue is that the LTC3892 switching at 200kHz means it has to charge and discharge every cycle and it thus the calculations for our FET indicate around 10mA of gate current.  There is no spec on the datasheet as to the amount of current the chip can source or sink, but it does appear we are frying the high side gate driver.