Peak Current Mode Control of Boost Converter

[jeevanreddy061]

Hello Experts,

I am currently working on a PCM Boost Converter. I Know the basic working and operation of this converter. I have designed CPM Boost Converter in LTSpice and its working fine in steady state. But during the transients, i am getting huge spikes. I don't know the reach for this. I tried changing the Compensating network and Error Amplifier but its almost the same expect for the starting ripples being decreased.

I designed it for an input voltage of 5V and output voltage of 24V.

Secondly, i started using a universal op-amp for both Compensator network and EA. I really don't know on what criteria i should be choosing a particular op-amp / Trans-conductance circuit. Any insight on this would be really helpful. (I am not more an analog guy, so layman work description is preferred)

To Sum,
1. On what factors, should i select my op-amp in the feedback network? How to decide on specs of these circuits like Gain, SR, Power Consumption, PM etc etc
2. Reason for such high transient Spikes. (I tried using the Soft-start, but it didn't work out. )

P.S: I am attachign the screenshots of my schematic and Simulation results.

https://obrazki.elektroda.pl/6712203500_1499024463.png
https://obrazki.elektroda.pl/7874037800_1499024463.png

 

[mtwieg]

Strange behavior at startup can usually be solved by setting realistic initial conditions. For example, force your error amplifier output to start at 0V (it's probably initialized at 5V as is), inductor current at 0, output voltage at 0V (or the nominal Vout). Also consider having it soft start by making the reference voltage ramp from 0V to 2.62V initially.

 

[treez]

Yes, and you dont have much output capacitance.
Make it bigger and see.
What is your max duty cycle?
Do you need slope compensation thereby?
Why dont you have a clamp on your maximum allowable current sense resistor voltage?...that would help.