Ericsson – Master Thesis – Interleaved ADC with Error Correction Lookup Table

Background

Are you up for the challenge to develop next generation integrated circuits for our continued leadership in mobile communications? In radio base stations, high-speed, time-interleaved, analog-to-digital converters (ADCs) are used to handle wide band signals. In this technique several lower speed sub-ADCs are used in parallel in a time interleaved fashion, so that when N sub-ADCs are used, each sub-ADC only needs to process every N:th sample, hence reducing the speed requirement of each sub-ADC by N times. However, due to mismatch between the sub-ADCs, such as offset in comparators, non-linearities are introduced. In this thesis we want to investigate randomizing and averaging techniques to mitigate these mismatch errors. In short, the average values of all sub-ADCs are used as the reference to which all sub-ADCs are correct. The correction values are stored in N individual look up tables. The thesis incudes both system-, and lower-level simulations.

Thesis Description

The following steps are envisioned as part of the thesis work:

• Literature survey to find current- and the state-of-the-art solutions.
• System level modeling in MATLAB
• Schematic design of critical building blocks and transistor level verification
• The thesis work will be concluded with a presentation for the Ericsson team.

Qualifications

• This project aims at students in electrical engineering, computer engineering or similar with interest in full custom integrated circuit design.
• Analog/digital circuit design basics (relevant coursework).
• Experience in transistor schematic design (Virtuoso IC) and circuit verification (Spectre simulator).
• Custom layout design experience (preferred but not mandatory).

Contact Persons

Recruiting Manager

Niklas Andersson                                                                                         Håkan Bengtsson

+46 722 20 43 78                                                                                        +46 725 39 81 77

niklas.b.andersson@ericsson.com                                                          hakan.bengtsson@ericsson.com