A High Speed DAC Architecture for Continuous Time Pipeline ADC

A High Speed DAC Architecture for Continuous Time Pipeline ADC

Abo Alainein, Mohammed (TU Delft Electrical Engineering, Mathematics and Computer Science)

Bolatkale, M. (mentor)
Bajoria, Shagun (mentor)
Liu, Qilong (mentor)
Alavi, S.M. (graduation committee)

Delft University of Technology

Electrical Engineering | Electronic Instrumentation

2023-03-24

This thesis provides an investigation of the architecture and the design of the coarse DACs in continuous time pipeline (CTP) ADC to achieve high SFDR performance within a large bandwidth at sampling frequency of 4.8 GHz in TSMC 28nm technology.
Mismatch errors of the coarse DACs in CTP ADC are very critical as they introduce distortion and leak the quantization noise of the coarse stages to the output. Conventional calibration techniques such as dynamic element matching (DEM) linearize the DACs by converting the DAC distortion to white noise. However, after the linearization, the residual gain errors of the DACs remain. As a result, the quantization noise of the coarse quantizers leak to the output and degrade the performance of the CTP. Therefore, the residual gain errors of the DACs need to be estimated and calibrated. A resistive DAC architecture is proposed in the first stage of the CTP. The proposed architecture employs conventional DEM technique and is verified within the first stage of the CTP. 

Furthermore, two new innovative techniques are presented in this thesis. The first technique, advanced dynamic element matching (ADEM), translates both the distortion and the gain errors due to element mismatch of the DACs in multi-stage CTP ADC into white noise. The second technique, advanced data weighted averaging (ADWA), noise shapes both the the distortion and the gain errors of the DACs. Therefore, the presented techniques do not require additional digital calibration for element mismatch errors. Finally, a DAC architecture is presented that allows a feasible implementation of the presented techniques. The techniques are verified using simulations in MATLAB and Cadence. However, The presented techniques require the CTP stages to have equal impedances.

ADC
DAC
ADEM
ADWA
high speed DAC
DAC calibration
CT Pipeline

http://resolver.tudelft.nl/uuid:97be441d-c589-4845-8428-92e46da31316

2026-01-01

Student theses

master thesis

© 2023 Mohammed Abo Alainein