Analysis and Calibration of Nonbinary-Weighted Capacitive DAC for High-Resolution SAR ADCs

• This brief analyzes the effect of capacitor variation on the design of high-resolution nonbinary-weighted successive-approximation-register analog-to-digital converters in terms of radix, conversion steps, and accuracy. Moreover, the limitation caused by the one-side redundancy of the nonbinary-weighted network is addressed and a corresponding solution with a mathematical derivation is provided. In order to relax the mismatch requirement on the capacitor sizing while still ensuring enough linearity, a bottom-up weight calibration technique accounting for noise and offset errors is proposed, and its effectiveness is demonstrated. This calibration approach can be easily incorporated into a charge-redistribution converter without modifying its main architecture and conversion sequence.

Ämnesord

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

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

Nyckelord

Capacitor variation; digital error correction; nonbinary weighted; redundancy; successive approximation; successive approximation register (SAR) analog-to-digital converters (ADCs); weight calibration

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)