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Showing posts from November, 2025

Buck Convertor simulation in LTSPICE

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 I have been doing a buck converter simulation recently. Let's go with some basic or normally used requirements for the buck converter. 1. The first step would be calculating ripple current. `\triangle I= K\times I_{out}` `\triangle I= 1  Amps` 2. Now, calculate the ripple Voltage `\triangle V= V_{r}\times V_{out}`                                                             `\triangle V= 5mV` 3. Let's calculate the Duty cycle, D `D=\frac{V_{out}}{V_{i n}}` `D=0.4167` 4. The value of the Inductor can be calculated by `  L=\frac{Vi n\times D\times (1-D)}{\triangle I \times F_{s}}` `L=116 mH` 5. Finally, calculating the output Capacitance value `C=\frac{Vi n\times D\times (1-D)}{8\times\triangle V\times L\times C \times F_{s}^{2}}` `C=1mF` I made an Excel with the formula. I have given the snapsho...

Mosfet Drain current Equations

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Knowing how to solve the MOSFET equation is an important thing in circuit design, as MOSFETs are used in most applications as a Switch. To mention the working of MOSFET in simple terms, we will control the flow of drain current by applying a voltage between the Gate and Source terminals. The calculation of drain current depends on which region the MOSFET is working in. Regions of MOSFET: There are three regions of operation for MOSFETs. Cut off region Linear or Ohmic or triode region Saturation region If the Gate-Source voltage(Vgs) is less than the gate threshold voltage(Vth), mosfet will not turn on, and we call it as Cut off region. If the Gate-Source voltage(Vgs) is more than the gate threshold voltage(Vth), and mosfet turns on, it can work either in the Linear or in the saturation region , depending on the applied Drain to Source Voltage(Vds). I have written the equation in the solution solver tool for solving the circuit. By using the above equations, we can solve the MOSFET circ...