Help me to simulate INL and DNL using Cadence

Re: INL,DNL measurement

vijay_nag said:

Hi friends,

I have got the INL and DNL errors of the ADC using the code density method. When i do transient simulation for this method no codes are missing. But when i do DC analysis of the design by sweeping the input voltage i find that there are a lot of missing codes. What does this indicate? Does it mean that the code density method is giving wrong results? Can anyone please explain me this discrepency.

Regards,
Vijay

Click to expand...

Sorry for my knowledge was exhausted. I don't know what it is "the code density method" you suggested.

and I don't know how do you set up your environment for transient INL/DNL measurement and DC INL/DNL measurement.

If you tell me how did you set up your environment to measure INL/DNL,

I may help you.

Regards,
020170

Re: INL,DNL measurement

Thanks vijay..

Re: INL,DNL measurement

020170 said:

vijay_nag said:

Hi friends,

I have got the INL and DNL errors of the ADC using the code density method. When i do transient simulation for this method no codes are missing. But when i do DC analysis of the design by sweeping the input voltage i find that there are a lot of missing codes. What does this indicate? Does it mean that the code density method is giving wrong results? Can anyone please explain me this discrepency.

Regards,
Vijay

Click to expand...

Sorry for my knowledge was exhausted. I don't know what it is "the code density method" you suggested.

and I don't know how do you set up your environment for transient INL/DNL measurement and DC INL/DNL measurement.

If you tell me how did you set up your environment to measure INL/DNL,

I may help you.

Regards,
020170

Click to expand...

Hi 020170,

In code density (histogram) method we apply a slow varying ramp signal at the input of the ADC. We sample the stair output of the ADC. The sample on the codes are known as code hits. Now the average code hit is found and using this we calculate the code width of each code in terms of LSBs. Now from this DNL for each code can be found by by substracting 1 (nominal DNL) from the width of each code. INL is the running sum of DNL. There is a document i am attaching where this method is explained.

Get book here, read chapter 12:

/Cl
Regards,
Vijay

Re: INL,DNL measurement

hi vijay..plz mail me pdf regarding inl calculation..i am not having enough points to download..plz farward to this id: venkat.sanam@gmail.com

Re: INL,DNL measurement

vijay_nag said:

020170 said:

vijay_nag said:

Hi friends,

I have got the INL and DNL errors of the ADC using the code density method. When i do transient simulation for this method no codes are missing. But when i do DC analysis of the design by sweeping the input voltage i find that there are a lot of missing codes. What does this indicate? Does it mean that the code density method is giving wrong results? Can anyone please explain me this discrepency.

Regards,
Vijay

Click to expand...

Sorry for my knowledge was exhausted. I don't know what it is "the code density method" you suggested.

and I don't know how do you set up your environment for transient INL/DNL measurement and DC INL/DNL measurement.

If you tell me how did you set up your environment to measure INL/DNL,

I may help you.

Regards,
020170

Click to expand...

Hi 020170,

In code density (histogram) method we apply a slow varying ramp signal at the input of the ADC. We sample the stair output of the ADC. The sample on the codes are known as code hits. Now the average code hit is found and using this we calculate the code width of each code in terms of LSBs. Now from this DNL for each code can be found by by substracting 1 (nominal DNL) from the width of each code. INL is the running sum of DNL. There is a document i am attaching where this method is explained.

Regards,
Vijay

Click to expand...

I read your link pdf file

Wolud you tell me what is the name of the book you linked ?

thanks for the link file

Re: INL,DNL measurement

020170 said:

I read your link pdf file

Wolud you tell me what is the name of the book you linked ?

thanks for the link file

Click to expand...

Hi 020170,

This is a chapter from the book "An Introduction to Mixed Signal IC Test and Measurement" by Mark Burns and Gordon W Roberts. It is already uploaded in the board. The link is

Regards,
Vijay