PSD using PWELCH function

Hi,

I am trying plot psd using PWELCH function of the voltage vs time plot saved from simulation.

Unfortunately, the time axis does not have uniform time stamps. The time stamps are varying depending upon amount of voltage change. Do I need to worry about this when estimating PSD using PWELCH function?

Below is my code segment for length(A) = 50000 points in time_data & volt_data.

hann_win = length(A)/2;

nfft = length(A)/2;

overlap = 0;

Fs = 100e9;

t=time_data;

sig=volt_data;

[Pxx,freq] = pwelch(sig,hann_win,overlap,nfft,Fs);

Pxx = Pxx.*length(A);

plot(freq,(10*log10(Pxx))+30) %Pxx power density in dBm (1mW ref power = +30)

Please advise if I need to re-adjust the volt_data for having uniform time stamp before using PWELCH?

Harvijay