cupoftea
Advanced Member level 6
We are doing a 3kW Half bridge converter. Vin 600V, vout = 24v.
Done in voltage mode for obvious reasons. (Split cap balancing etc)
Cant we just find the output LC resonant frequency....(which is also the frequency of the
troublesome output double poles).
So then all we do is find the Output capacitance.
Then add ESR in series with it such that 1/(2.pi.ESR.Cout) = the aforementioned
resonant frequency.
..then we have an ESR zero which cancels one of the dreaded output LC filter poles.
And then our power stage dynamics have just one output pole instead of the troublesome pole pair.
This makes our feedback compensation much easier, and indeed we only need type 2 feedback compensation.
Is this right?
Why dont people do this?
Done in voltage mode for obvious reasons. (Split cap balancing etc)
Cant we just find the output LC resonant frequency....(which is also the frequency of the
troublesome output double poles).
So then all we do is find the Output capacitance.
Then add ESR in series with it such that 1/(2.pi.ESR.Cout) = the aforementioned
resonant frequency.
..then we have an ESR zero which cancels one of the dreaded output LC filter poles.
And then our power stage dynamics have just one output pole instead of the troublesome pole pair.
This makes our feedback compensation much easier, and indeed we only need type 2 feedback compensation.
Is this right?
Why dont people do this?