Optimum value of dummy preamplifer for reducing offset error in ADC

[yen]

Dear all,
I read papers about flash adc.
Using average resistor can reduce offset error.
I have some questions.

1.It must add dummy preamplifier.

optimum value is

1/3*(Total preamplifer) = Dummy preamplifier

But I read some papers which don't use optimum value.

Why?

2.Why use resistor the offset value can improve?
I know it's impulse reaponse can be a filter.
Can you tell me detail ?
Thanks.

 

[vivicai]

Average resistor

co-ask

 

[maxwellequ]

Re: Average resistor

I advise you to read:


H. Pan and A. Abidi, “Spatial filtering in flash A/D converters,” IEEE Trans. Circuits Systems II, vol. 50, pp. 424-436, Aug. 2003.

P. Figueiredo and J. Vital, “Averaging technique in flash analog-to-digital converters,” IEEE Trans. on Circuits and Systems I, vol. 51, pp. 233-253, Feb. 2004.

P. Figueiredo and J. Vital, “Termination of averaging networks in flash ADCs,” in Proc. IEEE Int. Symp. on Circuits and Systems, vol. I, pp. 121-124, May 2004.

Regards