The 25th anniversary of the European Solid-State Circuits Conference (ESSCIRC'99) was held 21-23 September 1999 in Duisburg, Germany. The conference featured a total of 110 papers: eight invited talks, 63 regular papers presented orally, and 39 posters. The following is a brief summary of some of outstanding ESSCIRC'99 papers.
Among the numerous papers on analog circuits, two papers of special interest could be found. Paper 1.3.3, "A low-power BiCMOS op amp with integrated current mode charge pump," by R. St. Pierre, featured an operational amplifier that consumes only 4 µA at 2.4-5.5 V power supply range while operating rail-to-rail. The current mode charge pump appears to be superior to the voltage mode charge pump usually used. In Paper 2.2.1, S. L. J. Gierkink et al. discussed how to reduce 1/f-noise and power dissipation of MOS transistors using "switched-bias." This technique relies on on/off-switching of a MOSFET bias, thus making it periodically operate in a mode of strong inversion and accumulation. Measurements of a CMOS oscillator employing this technique have confirmed noise and power reduction according to the theory.
Paper 2.6.1 was devoted to the modeling of digital substrate noise. M. van Heijningen et al. have developed a SPICE substrate model that makes it easy to evaluate substrate noise and its impact on circuit performance. The validity of the model has been corroborated by measurements of realized circuits.
In Sessions 2.7 and 2.8, two papers on VCOs were presented that received wide attention. The first contribution, Paper 2.7.2 by A.M. Niknejad et al., outlined design and integration of two low-phase noise VCOs operating at 2.9 GHz and 4.4 GHz. They were implemented in an ft = 25 GHz bipolar process. In Paper 2.8.2, De Muer et al. introduced a 2 GHz LC-VCO, also with low-phase noise. Fabricated in a 0.65µm Bi-CMOS process, it employs integrated planar inductors. In addition, the flicker noise upconversion factor has been optimized to ensure low noise.
Mixed-signal circuits are presently receiving wide attention. In Paper 3.1.1, "Microelectronic components for a retina implant system," S. Kolnsberg et al. showed design and realization of components for a retina implant system that provides visual sensations to blind patients. These include a miniature CMOS camera with 140 dB dynamic range, an implantable power and data receiver, and a stimulator chip with integrated electrodes. Paper 3.3.1 by C. Rooman et al. described an asynchronous 250 Mb/s optical receiver with integrated photodetectors in standard 0.6 µm CMOS technology. It features 10 channels, while one channel is used as reference. Each channel contains a spatially modulated light detector and a low offset receiver.
In Session 3.4, two papers were presented that feature interesting image sensors. The first, Paper 3.4.1 by S. Benthien et al., employed an amorphous silicon thin film used as a photodetector that is deposited on an ASIC implemented in standard CMOS. Two imagers have been implemented: one with local autoadaption for digital photography and a second one with high dynamic range for automotive applications. In Paper 3.4.2, M. Sanchez et al. presented a CMOS imager in standard technology that is also intended for use in automotive applications. The high dynamic range has been achieved due to the use of the multiexposure principle and gain control.
ESSCIRC'99 was a highly successful conference. It remains an important annual forum for European engineers and scientists working in the area of microelectronic circuit design and continues to attract more and more participants from overseas.
Prof. B. J. Hosticka
ESSCIRC'99
Technical Program Chair