A dynamic characterization of analog-digital converter in-tegral nonlinearity (INL) is considered. When using a plu-rality of test frequencies in the measurement set-up, thedynamic errors of the converter are characterized. TheINL is modeled by low and high code components - LCFand HCF, respectively. The LCF and HCF are parameter-ized and a least squares method is derived for the estima-tion of the parameter values from obtained measurements.A closed form solution to the estimation problem is de-rived and its performance is illustrated by a numerical ex-ample. The proposed method is believed to be fruitful inwide-band characterization of analog-digital converters atradio frequency, and thus of importance for the evaluationof modern and future wireless communication systems.