The Integrator block is a simple integration stage that approximates the integral with respect to time of an input signal.

The block also includes gain and input offset parameters to allow for tailoring of the required signal, and output upper and lower limits to prevent convergence errors resulting from excessively large output values. These limits specify integrator behavior similar to that found in an operational amplifier-based integration stage, in that once a limit is reached, additional storage does not occur. Thus, the input of a negative value to an integrator which is currently driving at the out_upper_limit level will immediately cause a drop in the output, regardless of how long the integrator was previously summing positive inputs. The incremental value of output below the out_upper_limit and above the out_lower_limit at which smoothing begins is specified via the limit_range parameter.

In AC analysis, the value returned is equal to the gain divided by the radian frequency of analysis.

Truncation error checking is included. This should provide for a more accurate simulation of the time integration function, since the model will inherently request smaller time increments between simulation points if truncation errors would otherwise be excessive.


Parameter Description Default
in_offset Input offset. 0
gain Gain. 1
out_lower_limit Output lower limit.  
out_upper_limit Output upper limit.  
limit_range Upper and lower limit smoothing range. 1.0e-6
out_ic Output initial condition. 0