Optimal index-bit allocation for dynamic post-correction of analog-to-digital converters

• Signal processing methods for digital post-correction of analog-to-digital converters (ADCs) are, considered. ADC errors are in general signal dependent, and in addition, they often exhibit dynamic dependence. A novel dynamic post-correction scheme based on look-up tables is proposed. In order to reduce the table size and, thus, the hardware requirements, bit-masking is, introduced. This. is to limit the length of the table index by deselecting index bits. At this point, the problem of which bits to use arises. A mathematical analysis tool is derived, enabling the allocation of index bits to be analyzed. This analysis tool is applied in two optimization problems, optimizing the total harmonic distortion and the signal-to-noise and distortion ratio, respectively, of a corrected ADC. The correction scheme and the optimization problems are illustrated and exemplified using experimental ADC data. The results show that the proposed correction scheme improves the performance of the ADC. They also indicate that the allocation of index bits has a significant impact on the ADC performance, motivating the analysis tool. Finally, the optimization results show that performance improvements compared with static look-up table correction can be achieved, even at a comparable table size.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Signalbehandling (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Signal Processing (hsv//eng)

Nyckelord

analog-to-digital converter

calibration

dynamic correction

Hadamard transform

optimization

compensation

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)