Efficient Noise Injection Methodology for Sample and Hold Circuits in AMS Behavioral Models

In the field of analog mixed-signal circuits, Sample-and-Hold (S/H) circuits are frequently used as a key component in other circuits to preserve an analog voltage for downstream processing, as done in Analog-to-Digital Converters (ADCs). When developing and validating these, simulative methods are often used on the basis of behavioral models. One of the faults to be examined is signal noise and how it affects the circuits' behavior. Unfortunately, simulations for noise-injected input voltages involve a very high computational effort. This paper presents an efficient noise injection method in which noise is only injected at crucial time points during the simulation. Thus, the number of samples instead of the pure simulated time is decisive for the computational effort. As a result, our method achieves a significantly lower required computing time equal to transient analysis without noise. An implementation in VerilogAMS is introduced and the simulation results are presented.