| SimElectronics™ | |
SPICE-Compatible Sources
The Exponential Current Source block represents a current source whose output current value is an exponential pulse as a function of time and is independent of the voltage across the terminals of the source. The following equations describe the current through the source as a function of time:
where:
I1 is the Initial value, I1 parameter value.
I2 is the Pulse value, I2 parameter value.
TDR is the Rise delay time, TDR parameter value.
TR is the Rise time, TR parameter value.
TDF is the Fall delay time, TDF parameter value.
TF is the Fall time, TF parameter value.
The block uses a small conductance internally to prevent numerical simulation issues. The conductance connects the + and - ports of the device and has a conductance GMIN:
By default, GMIN matches the Minimum conductance GMIN parameter of the SPICE Environment Parameters block, whose default value is 1e–12.
To change GMIN, add a SPICE Environment Parameters block to your model and set the Minimum conductance GMIN parameter to the desired value.
The value of the output current at time zero. The default value is 0 A.
The asymptotic value of the output current when the output is high. The default value is 0 A.
The rise time delay. The default value is 0 s.
The time it takes the output current to rise from the Initial Value, I1 value to the Pulse Value, I2 value. The default value is 1e-09 s. The value must be greater than 0.
The fall time delay. The default value is 0 s, which differs from the SPICE default value.
The time it takes the output current to fall from the Pulse value, I2 value to the Initial value, I1 value. The default value is 1e-09 s. The value must be greater than 0.
The block has the following ports:
Positive electrical voltage.
Negative electrical voltage.
| Diode (SPICE) | Exponential Voltage Source | |
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