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?
Similar question in: https://ez.analog.com/power/f/q-a/163136/ltc3779-4-switch-design-problem
Thank you for your link, I read the https://ez.analog.com/power/f/q-a/163136/ltc3779-4-switch-design-problem , it is similar to my question 1, so that I could understand the answer to my question 1 is "NO".
But I could not find the answer for my question 2 & 3.....
Do you have any information could help me?
For Questions 2
it is possible to do so however it would be complex specially if you would target a fully isolated system
Mind looking at these controller as alternates ?
For Questions 3
The comparator is used for gate drive functionality of the IC.
A bit of which is discussed on page 30 of the data sheet
Hi Mikee :
Thanks for reply.
For Question 2,
I check the link you posted, lt8302 and ltc3803, it looks like use for fly-back control?
Fly-back is usually use for low power, right? or the transformer may be designed very big.
For adp1032, I am not sure it is software control or not, but I thought the transformer is the same problem.
For Question 3,
The page 30 of datasheet discuss with how the function work, it works to prevent the reverse current from output to input.
But I am not sure what will happen if this function does not work, and further condition if my Vin is always higher than SW1, what will happen to my circuit, this is what I want to know.
And I also want to know is this only function that Vin and SW1 use for?
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.
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.