Hi Elango,
I don't see anything that should cause this to have an issue, though as you mentioned you may need to experiment some with the oscillator frequency due to the high gate capacitance.
My only concern at the higher temperatures is for the FET power dissipation, but even then I don't see too much risk. I calculate (by t = CV / I = 1100 pF * 15 V / 15 mA ≈ 1 us) that the rise time should still be small relative to the PWM frequency so I don't see too much issue. If you find any particular concerns, we can help you out with them, just be sure to upload the scope shots so we can see what is going on.
I don't see anything that should cause this to have an issue, though as you mentioned you may need to experiment some with the oscillator frequency due to the high gate capacitance.
My only concern at the higher temperatures is for the FET power dissipation, but even then I don't see too much risk. I calculate (by t = CV / I = 1100 pF * 15 V / 15 mA ≈ 1 us) that the rise time should still be small relative to the PWM frequency so I don't see too much issue. If you find any particular concerns, we can help you out with them, just be sure to upload the scope shots so we can see what is going on.