Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
This work is aimed to characterize and develop a calibration methodologyto compensate pipeline analog-digital converters (ADC)s. In this work theintegral nonlinearity (INL) is characterized, modeled and used to develop onenew method in order to obtain a calibration sequence.One of the most important ADC characteristics is the INL. The INL describesthe deviation between the ideal output of an ADC and the current outputlevel. The INL has a dynamic behavior since it depends on input signal characteristics.The INL model can be subdivided into two components: the lowcode frequency (LCF) and the high code frequency (HCF). The HCF is astatic term that depends only on the output code k and is related to the ADCcircuitry imperfections. We will not model the HCF in the work. The dynamicpart is the LCF and depends on the input signal characteristics. The LCF ismodeled by a polynomial of order L depending on frequency m and the outputcode k.The harmonics of the ADC digital output are related to the LCF part ofthe INL. In this work, we will optimize the LCF and use it to calibrate the rstand higher Nyquist bands of a pipeline ADC. The basic idea of this model isto obtain an error sequence by an optimization process done in the frequencydomain. The optimal LCF frequency-dependent coecients are computed inan iterative process until the harmonics of the output spectrum are minimized.In the calibration process, the HCF part is used as a static look-up-table(LUT) and the dynamic part is performed using a frequency-dependent LCFpolynomial coecients.This optimization model gives notably better results than the INL model.The harmonics in the three rst Nyquist bands are attenuated using the modelexplained in this work.
Place, publisher, year, edition, pages
2013. , 59 p.
EES Examensarbete / Master Thesis
IdentifiersURN: urn:nbn:se:kth:diva-107273OAI: oai:DiVA.org:kth-107273DiVA: diva2:575397
Master of Science - Wireless Systems
2012-11-12, SIP room, Plan 3, Osquldas väg 10, Stockholm, 10:40 (English)
Medawar, Samer, Dr.
Händel, Peter, Prof.