d123
Advanced Member level 5
Hi,
I would like anyone interested in these topologies and/or with practical experience or knowledge of both SEPIC and Zeta to share their opinions.
I read that SEPIC positives are that it is more efficient, has lower input ripple; negatives are two RHPZ, high output ripple. Zeta positives are no RHPZ (easier control loop compensation and higher bandwidth possible as a result), low output ripple; negatives are higher input ripple, not as efficient.
Besides choices like needing minimum input ripple or minimum output ripple, say a delicate load would be better with a Zeta, are these topologies to all intents and purposes much of a muchness and amount to the same thing?
When would you choose one or the other and why?
What are real-world experiences and personal design tips and opinions of both?
Separately, as I'm not 100% clear on this one outside of simulation-land (...works wonderfully in the cartoon...) and typical preparatory calculations, please:
Is there anything unrealistic about a SEPIC with a load range of 10mA to 1.3A?
For such a load range, what is minimum inductor ripple I can get away with? Formula I use suggests 40%, is less possible, say 10% or 20% or will inductor saturate and maybe even 40% isn't enough?
Thanks.
I would like anyone interested in these topologies and/or with practical experience or knowledge of both SEPIC and Zeta to share their opinions.
I read that SEPIC positives are that it is more efficient, has lower input ripple; negatives are two RHPZ, high output ripple. Zeta positives are no RHPZ (easier control loop compensation and higher bandwidth possible as a result), low output ripple; negatives are higher input ripple, not as efficient.
Besides choices like needing minimum input ripple or minimum output ripple, say a delicate load would be better with a Zeta, are these topologies to all intents and purposes much of a muchness and amount to the same thing?
When would you choose one or the other and why?
What are real-world experiences and personal design tips and opinions of both?
Separately, as I'm not 100% clear on this one outside of simulation-land (...works wonderfully in the cartoon...) and typical preparatory calculations, please:
Is there anything unrealistic about a SEPIC with a load range of 10mA to 1.3A?
For such a load range, what is minimum inductor ripple I can get away with? Formula I use suggests 40%, is less possible, say 10% or 20% or will inductor saturate and maybe even 40% isn't enough?
Thanks.