waosai
Member level 2
dac sfdr
I want to test my DAC's SFDR spec in Hspice.
The spec. of the DAC is: 125-MHz/12-Bit
Someone tells me use the following relationship to setup my FFT analysis in hspice:
np*Tck=Tsig*N
where np is the sampling points with the value of 1024 usually; Tck=1/125MHz is the period of clock; Tsig is the period of sine wave; N the numbers of signal (N must be odd).
Then using FFT statement in hspice:
..................................
.param N=99
.param np=1024
.param fck=125E6
.param Tck=1/fck
.param starttime=100n
.param stoptime='starttime+np*Tck'
.fft v(out) np=1024 from=starttime to=stoptime
......................................
Anyone can tell me whether the above statement is right?
And another question. The scale of the circuit is very large. So it requires large time to complete the simulation for hspice(about two weeks on my pc, using hsim). Is there any method to solve this problem?
I want to test my DAC's SFDR spec in Hspice.
The spec. of the DAC is: 125-MHz/12-Bit
Someone tells me use the following relationship to setup my FFT analysis in hspice:
np*Tck=Tsig*N
where np is the sampling points with the value of 1024 usually; Tck=1/125MHz is the period of clock; Tsig is the period of sine wave; N the numbers of signal (N must be odd).
Then using FFT statement in hspice:
..................................
.param N=99
.param np=1024
.param fck=125E6
.param Tck=1/fck
.param starttime=100n
.param stoptime='starttime+np*Tck'
.fft v(out) np=1024 from=starttime to=stoptime
......................................
Anyone can tell me whether the above statement is right?
And another question. The scale of the circuit is very large. So it requires large time to complete the simulation for hspice(about two weeks on my pc, using hsim). Is there any method to solve this problem?