HIPADS: High-performance deep submicron CMOS analog-to-digital converters using low-noise logic

• Research unit: EU RFP
• Project number: 98.0170-2

Key words (English)

High-speed; analog-to-digital converters; delta-sigma

Alternative project number (English)

EU project number: 27917

Research programs (English)

EU-programme: 4. Frame Research Programme - 1.3 Telematic systems

Short description (English)

See abstract

Partners and International Organizations (English)

Coordinator: EPFL (CH)

Abstract (English)

The aim of this project is to develop three different A/D converters in deep submicron digital CMOS process. In some cases, a current steering logic solution has been compared to a standard static logic approach. Our contribution to the project consisted in realizing one of these ADCs which was aimed for video applications.
A fully integrated ADC test chip has been implemented in a 0.35um CMOS process with target specifications of 12-bit resolution while operating at 12.5 MSPS. The relative high-speed operation for a delta-sigma type of A/D converter is achievable using low oversampling ration (x16) and a 3-bit continuous-time modulator.The sampling frequency is 200MHz and several choices have been necessary for the high speed requirements. The digital-to-analog converter where the linearity is critical in the case of a multibit modulator uses a new ping-pong technique to reduce the glitches during clock transitions. A new technique for opamps has been used to achieve a high-gain in the baseband and a large bandwidth. Finally, the digital filter and the decimator have been optimized in terms of area and power consumption.
A significant achievement consisted in the realization of a high performance line driver, one of the key building blocks of the delta-sigma converter structure. With driving capability of 600pF and low output impedance of 1ohm, 100dB linearity has been achieved within 1MHz banwidth. The main applications of this circuit are communication networks and video.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 98.0170-2