Is there a function that can read a value from x-axis given the condition of y-axis?

[Alex Liao]

Hi,

I have a comparator circuit. I have print out an waveform of the Vout+. The x-axis is the time and the y-axis is the voltage. For example the voltage supply is 1V. I can see when the voltage raises from 0V to 90% of 1V, which is 900mV, how much time is needed or what is the current time in ns when it reaches 900mV.

I am wondering if there is a function that can return you one specific point (in ns) on the X-axis when Y reaches 900mV. Thus I do not need to manually measure/observe it. Maybe I need specify any time range such that it can only return me one value because the output wave maybe periodical and thus there are lots of point satisfying this requirement of 900mV on y-axis.

I am using Cadence ADE to run simulation and hope there is a function in the calculator or any ocean script that can do this.

Thanks,
Alex

 

[Dominik Przyborowski]

The proper function is a cross function. It returns a x value for which y value achieve given level.

 

[BradtheRad]

Can you rearrange the function so that X is the only thing to the left of the equals sign? Of course this will not be easy if the equation is complicated.

that can return you one specific point (in ns) on the X-axis when Y reaches 900mV

Set a range which is a little above and below your desired Y value. Example, Y>.88 and Y<.92.

Step through a range of X values which are likely to yield Y within that range.

A simple 'robot' algorithm will only catch one solution for Y=.9 (if that many).

You can also step backward, in smaller increments, then forward, in lesser and lesser increments, until you narrow in on a desired Y value.