A buck converter has the following specifications. Input voltage: 24 V to 36 V, output voltage: 12 V, output current: 2 A-10 A, MOSFET switching transition times, tf = tr = 40ns, RDS ON = 40m2, diode forward voltage drop = 0.8 V and switching frequency = 200 kHz. The MOSFET and the diode have a thermal resistance, Rejc, of 0.65 C/W each. The junction temperature is to be limited to 100C. Assuming that the MOSFET and diode are mounted on the same heatsink (with appropriate electrical isolation), calculate the maximum allowable thermal resistance, Resa for the heatsink. Neglect switching loss in diode and ripple in inductor current. Neglect thermal resistance from device case to heatsink. Assume ambient temperature to be 30C.