LTC3779 use in non-synchronous buck-boost converter

Dear Analog team:

I select LTC3779 for my DC/DC converter, and my customer is asking me to design this IC in non-synchronous buck-boost converter.

Would you kindly answer my following problem, thank you!

1. Could LTC3779 design in non-synchronous buck-boost converter? If the answer is NO, please tell me why and what damage will cause if I design this structure.

2. Could LTC3779 design with isolate driver IC like adum3224? If the answer is YES, please kindly share how to design the circuit, If the answer is NO, please tell me why and what damage will cause if I design this structure.

3. I saw the block diagram of LTC3779, the IC compare with voltage of Vin and SW1, what purpose is this function work for? What damage will cause if Vin is always bigger than SW1? What situation will happen if this function does not work?

LTC3779 block diagram

Thank you!!

Parents Reply
  • 0
    •  Analog Employees 
    on May 19, 2020 8:08 AM in reply to llin786


    For Question 2, 

    Can you discuss more on the reason on why you aim to use adum3224?

    My initial assumption is that you needed an isolated power supply that is why I have suggested Fly back controllers. 

    For Question 3,

    as can be seen on the block diagram the comparator output is input to the buck and boost logic blocks meaning if the conditions are not properly set the controller would not know what logic block should be active at the time and could not properly operate.