Boost Converter Simulation With LT1242 or LT246 PWM Controller

1246_Boost.asc

Hi, my name is Nebi. I am a hardware design engineer. I am working on a boost converter. My converter parameter is as follows.

Vin_min=20 VDC, Vin_max=31 VDC, Vout=75 VDC, Pout=2500 W and frequency=150kHz

I made simulations with LT1242 and LT1246 PWM Controllers in LtSpice. But I have some questions.

The simulation circuit and waveform graph are as follows. In the LT1246 simulation, the Mosfet PWM signal is intermittent. Something is resetting. I changed sense resistor but did not solve this problem. What could be causing this situation?

     

I set up the same circuit for LT1242. A similar reset situation happened here. If sense resistor value is not correct, how can I calculate this resistor value?

    

In addition, I did not find LTpowerCAD model for LT1242 and LT1246. Therefore I could not loop compensation. How can you help with this? Could it be that the output voltage is incorrect because my compensation values are wrong?

Thanks for be interest.

Have a nice day!