Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

On DNL/INL with reduced bits

Status
Not open for further replies.

abonic

Junior Member level 2
Joined
Dec 5, 2012
Messages
23
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,431
Hi, guys
If I only use the MSB K bits of a nominal N bits ADC (N>K), what's the relationship between the MSB K bits DNL/INL and N bits DNL/INL.

To give the question more apprehensible, assume the max DNLs/INLs for the MSB K bit and the nominal N bits are\[ DNL_K\]/\[INL_K\], and \[DNL_N\]/\[INL_N\] separately.

Can we have the following conclusions
\[DNL_N=2^{N-K}DNL_K\]
\[INL_N=2^{N-K}INL_K\]

Or there exists other statistical relationships

Thank You!
 

No, I don't think this will work, sorry: a reasonably good ADC shouldn't have DNL-, even INL-values greater than a few single bits (at least for N≦12), generally I'd estimate less than 2N-7.. 2N-8 bits, see e.g. here for a 10bit converter:
DNL-INL.png.
That means if you measure the DNL/INL values on the MSB K=8 for this N=10 bit converter, you'd get zero values as results.
 

Yeah, I understand what you mean in your case.
Let's now think about a bad case, where an 10-bit ADC has 16-LSB maximum DNL and 32-LSB maximun INL. What if we only use the MSB 9-bit to calculate DNL & INL, can we obtain 8-LSB maximun DNL and 16-LSB maximum INL for MSB-9 bit data.
 

... a bad case, where an 10-bit ADC has 16-LSB maximum DNL and 32-LSB maximun INL.
The other way round, usually: INL > DNL.
Anyway, such a bad ADC I'd through far, far away! ;-)

What if we only use the MSB 9-bit to calculate DNL & INL, can we obtain 8-LSB maximun DNL and 16-LSB maximum INL for MSB-9 bit data.
Sure, in such case - with N-K=1 (max. =2) - your above equations would work correctly.
 

It only a theoretical discussion, not a real case.:p
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top