Question

Please show equations used . Thanks

of2 Question 2 A controlled static switch has an "ON" forward voltage drop of 1.5V. Its forward leakage current in the "OFF" state is 2mA. ft is operated with a switching frequency of 10 KHz and a duty cycle of 50%. Neglect switching transition times. Determine the peak and average power dissipation in the switch

Answer 1

Given circuit For switch on voltage drop is 1.5 V V_CE (sat) = 1.5 V Forward leakage current is 2 mA beak = 2 mA switching frequency is 10 k Hz Duty cycle is d = 50% time for transition of switch is = 1/10 k = 10 ms For transistors power dissipation due to saturation voltage is P ON = VCE(sat) times IC IC = Vs - V CE (sat)/RL = 46 - 1.5/10 = 4.45 A to control power, switch is turned on & off periodically P oN (avg) = V CE (sat) times Ic times d = 1.5 times 4.45 times 0.5 3.33 w = 3.337 w P OFF (avg) = Vs times I leak times t off/T = 46 times 2 times 0.5 times 10^-3 = 0.046 w Peak power when P ON (peak) = (Vs - V CE) times Ic P OFF(peak) = Vs times (Ic - I leak) = 46 times (4.45 - 20 A) = 204 w