Question

Design a DC-DC boost converter, shown below, that converts an unregulated supply of 12.0 Vak into a load voltage of 30.0 Ve and load current of 0.25 A. The switching frequency of the transistor is 100 kHz. The transistor has an on-resistance of 0.15 Ω and the diode drops 0.7 V when it is conducting. The voltage ripple (Av) is taken as 20 mVpp The circuit has 80% conversion efficiency. Find the DC input-current (Iden), duty-cycle (D), inductance (L), power-dissipation across transistor (Po), power-dissipation across diode (Pdiode), capacitance (Co). Eunreg load

Answer 1

Stven DC DC Boost convexter 0.25A o 30V iven fveguon cy = 100KHz Swith Ne k noue fo a Boost, on verte Vout D 12 → 30-30D-12 > 30 = 3 O Given 1。-0.25 A Thon Dc n 0.25o. 625 Amp 30 0.25 Load Re sistance R Now D (1-D)2RT Induchan co L = 2 06 (o 4)XL20 2. 57-6 쌔

acitance Thon 0.25 X0.6鳳 AV Power despabon aciess duode 0.7 Volt Cliver) voltage at dode Source allyont IS Tso 626 A Power dissipated = 0.7×0.625 o.4375 wat No.s fouwe dissipabon aaoss suoitch. Given RoN 0.15A. No.9, Cuwont flowing (luoush swt th 1,ith 0.625-0.25 sorkh. 375 A Noue Power dussipated = 2R SSI 2