Interface ElectronicsLaboratory 04: Simulation and Analysis of 8bit R2R DACLab04 GroupA, ***910 A, ***726 P 
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Table 1 
The simulation of Ramp test for different frequencies are shown in the figure. The frequencies are varied from 10 Khz to 10 Mhz. 
figure3:10kHZ frequency 
figure4: 100kHZ frequency  
We can see from the graph that the Ramp is getting bad with the increasing frequencies. We got the better results for the frequencies between 2Khz to 10Khz. 
figure5:1MHZ frequency 
figure6:10Mhz frequency 
Settling time for the DAC is measured for both full scale and mid scale range. The figure shows the values for rising and falling edge of the clock signal. 
figure7: full scale rising time. 
figure8:full scale falling time.  
full scale rising time=13usec full scale falling time=16usec mid scale rising time=1.5usec mid scale falling time=0.049usec 
figure9:mid scale rising time 
figure10:mid scale falling time 
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figure12: INL,DNL for 2khz frequency 
figure13 
figure14:INL,DNL for 200khz frequency 
For the Sine measurement analysis of DAC we imported the 10bit sine file with 43 periods from the folder provided. The results of FFT and SNR is obtained from this. For both signals FFT shows the highest peak at around 43HZ ,but the noise level is varying. Noise level is greater for 50khz than 1khz signal. From the figure it can also be seen that ENOB= 7.9435 bits, which is less than 8 bit for 1khz signal. ENOB= 7.7823 bits, which is less than 8 bit for 50khz signal. 

In order to get the comparison for good and bad sine measurements, we have taken two different frequencies of 1Khz and 50Khz. The results in the figure shows that, although the noise is well under the highest value but as we increase the frequencies INL,DNL is very much crossing the limits of +/ 0.5 LSB range. 

For the calibration of sine we used the triangular wave and used that values to get the FFT points. 
figure21  
The calibrated data shows the better results for INL,DNL values than the non calibrated data The values of INL, DNL now is in the range of +/ 0.5 LSB 
figure22 