mosfet driving

I was reading this discussion - Interlock Discussion, because I want to design a Half Bridge MOSFET driver, with interlock. I recreated both the circuits in LTspice that were recommended The logic I want is - In1 In2 Op 0 0 both OFF 1 0 Up MOS ON, BOT MOS OFF 0...

I'm designing a variable power source from 5V to 30V with 600mA. Input voltage is VIN = 36V. I tried the below circuit. VREF is given from microcontroller DAC. I tried using N-MOSFET, P-MOSFET, NPN, PNP (with modifications). I set a the output voltage as 20V. This circuit works fine with no...