Index: simulation/sim/16_opamp_dc/16_opamp_dc.svg =================================================================== --- simulation/sim/16_opamp_dc/16_opamp_dc.svg (nonexistent) +++ simulation/sim/16_opamp_dc/16_opamp_dc.svg (revision 8810) @@ -0,0 +1,759 @@ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Index: simulation/sim/16_opamp_dc/index.html =================================================================== --- simulation/sim/16_opamp_dc/index.html (nonexistent) +++ simulation/sim/16_opamp_dc/index.html (revision 8810) @@ -0,0 +1,64 @@ + + +

16_opamp_dc: dc sweep

+ +

Scope

+

+In this simulation we are going to map a simple opamp circuit's gain +at different voltages (dc sweep). + +

The schematics

+

+The single-sheet schematic contains the opamp circuit with connectors, +suitable for the PCB workflow. +

+

+ +
Click the image to get the sch-rnd sheet; also requires this project.lht in the same directory
+

+ +

Opamp model

+

+This example uses the lm358 macromodel from sch-rnd's stock spice +library. This model is a subcircuit of the amplifier and simulates a +lot of limiters and parasitics. + +

Preparing for simulation

+ +

Q1

+

+The model uses the standard opamp pinout so the hardwired spice/pinnum +attributes on the terminals will simply work. +

+The simulation setup process is largely the same as in the +base example of dc op point. The simulation +setup in this example is called "dc gain". + +

Modifications

+

+This circuit needs three voltage sources, which are both added as modifications. +The first one is a DC 5V source connected to net Vcc (and GND). The second is +a DC -5V source connected to net Vneg (and GND). These are the power supply +rails of the opamp. +

+The third source is connected to the net in (and GND). Unlike other +sources in the examples so far, this one has a name: V1. This is important +because the analysis will need a named source for the sweep. + +

Sim setup: output config

+

+The analysis to use is dc (lin) which is a linear DC sweep: spice +will vary the voltage on V1 (selected in the source name field, refers to +V1 set up as a modification above). It is configured to run +from -50mV to +60mV on the input, increasing voltage by 2 mV steps. +

+At the end the input and output voltages are plotted. The plot will use +linear X axis because of the analysis is "(lin)". + +

+

+ +
Simulation setup dialog, third tab, after execution
+

+Because of the large amplification factor, the +input (red) trace is visible only when zoomed in. Index: simulation/sim/16_opamp_dc/sim_run.png =================================================================== Cannot display: file marked as a binary type. svn:mime-type = application/octet-stream Index: simulation/sim/16_opamp_dc/sim_run.png =================================================================== --- simulation/sim/16_opamp_dc/sim_run.png (nonexistent) +++ simulation/sim/16_opamp_dc/sim_run.png (revision 8810) Property changes on: simulation/sim/16_opamp_dc/sim_run.png ___________________________________________________________________ Added: svn:mime-type ## -0,0 +1 ## +application/octet-stream \ No newline at end of property