i need to kinow what are the specifications of the power supply you are designing.
you can find good referenceson current mode supply design on notes by lloyd dixon which are freely avalable on the net.
visit the link below.
h**p://focus.ti.com/lit/ml/slup091/slup091.pdf
I am designing a 5Vin, 3Vout average current mode control PWM non-sync buck converter. drawing up to 1A load current. The switch is external and I am using a PMOS power transistor.