I would like to learn how to obtain the Control-to-Output Frequency Response of a Contant On-Time (COT) Control of a Buck Converter using the Multitone Analysis tool. The parameters of the Converter are as follows:
- L = 300e-9 H
- C = 56e-6 F/560
- DCR = 0 Ohm
- ESR = 6e-3 Ohm
- R = 120e-3 Ohm
- Ton = 0.33e-6 s
- Fsw = 300e3 Hz;
The COT Controller was implemented using FSM. I've applied a perturbation signal to the reference input (Vref) and measured the reponse. Then using the Multitone Analysis Tool, used the following parameters
- Initial simulation period: 1e-4 (s)
- Frequency range: [1e3 150e3]
- Amplitude: 1e-3
- Perturbation: vref'
- Response: vo'
The image below ilustrates the schematic of the regulator.
The image below ilustrates the implementation of the COT Control using FSM.
The ideia is to get the Control-to-Output Transfer Function according to what was obtained in the following paper "New Modeling Approach and Equivalent Circuit Representation for Current-Mode Control", by Jian Li and Fred. C. Lee.
When I try to obtain the same results using the Multitone Analysis, this is what I get.
Thanks in advance.