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RF Electronics Chapter 2: Computer Simulation Page 29 2022, C. J. Kikkert, James Cook University, ISBN 978-0-6486803-9-0. corresponding reduction in output voltage. Changing t on to 2.67 s, results in 12V for a 2.4 Ω load. The 10 F capacitance and the nominal resistance result in a Q of 0.24, so that the transient response of the output voltage has minimal overshoot. The corresponding circuit of the buck converter is shown in figure 2.32. In figure 2.32, Voltage probes have been used for the measurement points. They are not really needed since VP1 is the same as the voltage at node 1 of the inductor, SRL.RL1@1 and VP2 is the same as SRL.RL1@2. The use of voltage probes makes it easier to identify the measurement locations. Figure 2.32. Buck DC-DC converter circuit. Figure 2.33. Frequency setting (L) and measurement type window (R) for transient simulation. To specify the measurement points, select Nonlinear and Current and Itime for current measurements versus time and Voltage and Vtime for voltage measurements versus time. Ensure that the simulator selected is Aplac Trans for the transient analysis required, as shown on the right in figure 2.33. This then turns on the APLAC transient analysis and turns off any HB analysis for that measurement. Then select the location of the voltage or current to be measured, by double clicking on the small window showing "..." next to "Measurement Component" in figure 2.33(R). This then shows the circuit diagram of figure 2.32 and allows the selection of the component or lead where the current or voltage is to be measured and plotted. For the simulation, the first step is to set the frequency of operation by setting the frequencies in the project options as a single frequency of 100 kHz as shown in figure 2.33. Setting this frequency automatically controls the time steps used in the simulation RF Electronics: Design and Simulation 29 www.cadence.com/go/awr

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