MC33063A: write simulation but bad signals

Part Number: MC33063A

Hello,

I simulatet a stepup converter.

I have already set up the circuit and received metrologically similar / same signals

But I think there is something going wrong because the signals look bad.

At first the simulation shematic

Now the meassured signals:

I cant find there a fix frequenzy, more some swinging signals.

In application normaly we have constant current of 50 to 100mA and some Peak of 21A für 1,2µs when the IGBTs are switching. They swithing whith 4, 8 or 16kHz.

for calculation:

worst case at 16kHz 62,5µs/1,2µs * 21A = ~400mA

400 +50 mA =450mA

whith an output of 16V, an input of 12V and a minimal sw-freq. 55kHz I've calculate:

So I hope you can helb me.

If you would like to give me your mail adress I can send the Simulation-Model