Performance Analysis—Inverter Rise Time

The Performance Analysis capabilities of Probe are used to view properties of waveforms that are not easily described. Amplifier bandwidth, rise time, and overshoot are examples. To calculate the bandwidth of a circuit, you must find the maximum gain, and then find the frequency where the gain is down by 3 dB. To calculate rise time, you must find the 10% and 90% points, and then find the time difference between the points. The Performance Analysis gives us the capability to plot these properties versus a parameter or device tolerances. The Performance Analysis is used in conjunction with the Parametric Sweep to see how the properties vary versus a parameter. The Performance Analysis is used in conjunction with the Monte Carlo analysis to see how the properties vary with device tolerances. In this section we will plot the rise time of a BJT inverter versus the value of the collector resistor. See Section 9.G to leam how to use the Performance Analysis in conjunction with the Monte Carlo analysis. 

Suppose that for the example of Section 6.K we would like to see a plot of how the rise time is affected by the value of the collector resistor. This plot can be accomplished using the Performance Analysis capabilities of Probe. Repeat the procedure of Section 6.K. When Probe runs, select all of the runs and add the trace V (VO)  

We see that all of the traces reach the final value of 5 V. To plot the rise time versus the parameter R val we must select the Performance Analysis. From the Probe menu select Plot and then Axis Settings. By default, the X Axis tab is selected  

Under Processing Options we see that the square D next to Performance Analysis does not have a checkmark in it, indicating that it is not enabled. To enable the Performance Analysis click the LEFT mouse button on the text 

Performance Analysis. The square should fill with a checkmark IS, indicating that the Performance Analysis is enabled  

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