# boost converter circuit simulation in LTSpice

Could you please explain why the V(R1) is not 2V?

I'm studying boost converter using LTSpice. According to theory the output voltage of this circuit should be determined by the duty cycle of the square wave which is generated by the switch. Here I used 50% and expected that the Vout would be 2*Vin. But the simulation results in this.

From this simulation I found that the Vout is dependent of L, C and R. Is that true? I don't understand what is wrong.

• The interaction is more complex, you need frequency too, and obviously the higher your load, the lower your voltage. For a fixed set of parameters you can however say that varying one certain parameter has a specific result. – PlasmaHH Jul 7 '16 at 9:03
• Frequency should be high enough to neglect L, C and R. Then the simulation should be long enough- like tens of cycles. – Gregory Kornblum Jul 7 '16 at 9:10

$1 + \dfrac{V_{IN} D^2T}{2 L I_{OUT}}$