Question

Given: A MOSFET is used in a switching power-pole found in Fig. 2-4a of the text. The operating conditions are as follows: Vin 35V, 6 A, the switching frequency fs 300 kHz, and the duty ratio d 0.4 a) Consider the diode in the power pole. Assuming an offset voltage forward bias model of the free-wheeling diode in which VM 1.2 V, calculate the average forward power loss in the diode HINT: Consider Eq. 2A-1 b) In the diode reverse recovery characteristic shown in Fig. 2A-1, ta 10 ns, tr 25 ns, and IRRM 2 A, calculate the average switching power loss in the diode. HINT: Consider Eq. 2A-2. c How much in overall average switching loss in MOSFET will be if the impact of diode reverse recovery is included during MOSFET switching? Assume tri-th = 20ns and t,-to-25ns If the maximum junction temperature of the diode is Ti(max) 110°C, what is the maximum acceptable thermal resistance from junction to ambient if the maximum ambient temperature is Ta(max) 40°C? d) Paode,F = (I-d). VFylo (2A.1) DS diode,sw- i72

Answer 1