STMicroelectronics

About: STMicroelectronics is a company organization based out in Geneva, Switzerland. It is known for research contribution in the topics: Transistor & Signal. The organization has 17172 authors who have published 29543 publications receiving 300766 citations. The organization is also known as: SGS-Thomson & STM.

25 Gbps low-voltage hetero-structured silicon-germanium waveguide pin photodetectors for monolithic on-chip nanophotonic architectures

Abstract: Near-infrared germanium (Ge) photodetectors monolithically integrated on top of silicon-on-insulator substrates are universally regarded as key enablers towards chip-scale nanophotonics, with applications ranging from sensing and health monitoring to object recognition and optical communications. In this work, we report on the high-data-rate performance pin waveguide photodetectors made of a lateral hetero-structured silicon-Ge-silicon (Si-Ge-Si) junction operating under low reverse bias at 1.55 μm. The pin photodetector integration scheme considerably eases device manufacturing and is fully compatible with complementary metal-oxide-semiconductor technology. In particular, the hetero-structured Si-Ge-Si photodetectors show efficiency-bandwidth products of ∼9 GHz at −1 V and ∼30 GHz at −3 V, with a leakage dark current as low as ∼150 nA, allowing superior signal detection of high-speed data traffic. A bit-error rate of 10−9 is achieved for conventional 10 Gbps, 20 Gbps, and 25 Gbps data rates, yielding optical power sensitivities of −13.85 dBm, −12.70 dBm, and −11.25 dBm, respectively. This demonstration opens up new horizons towards cost-effective Ge pin waveguide photodetectors that combine fast device operation at low voltages with standard semiconductor fabrication processes, as desired for reliable on-chip architectures in next-generation nanophotonics integrated circuits.

MPEG-2 decoding with a reduced RAM requisite by ADPCM recompression before storing MPEG decompressed data

Abstract: The video RAM requisite of an MPEG-2 decoder is reduced by recompressing according to an adaptive pulse code modulation scheme (ADPCM) at least the I and P pictures, after MPEG-2 decompression and before storing the relative data in the video RAM. The ADPCM recompressed and coded data written in the video RAM are decoded and decompressed during the reconstruction of a B-picture to be displayed.

Positive charge pump

Abstract: A charge pump comprises a plurality of stages connected in series, an input terminal of the charge pump being connected to a voltage supply and an output terminal of the charge pump providing an output voltage higher than the voltage supply. Each stage comprises unidirectional current flow MOS transistor means connected between a stage input terminal and a stage output terminal allowing current to flow only from said stage input terminal to said stage output terminal, and a first capacitor with one plate connected to said stage output terminal and another plate driven by a respective first digital signal periodically switching between ground and said voltage supply. The unidirectional current flow MOS transistor means of the stages have independent bulk electrodes, and a bias voltage generator circuit is provided for biasing the bulk electrodes of said unidirectional current flow MOS transistor means at respective bulk potentials which become progressively higher going from the stages proximate to said input terminal to the stages proximate to said output terminal of the charge pump.

Adaptive motion estimator

Abstract: A method and apparatus of encoding digital video according to the ISO/IEC MPEG standards (ISO/IEC 11172-2 MPEG-1 and ISO/IEC 13818-2 MPEG-2) using an adaptive motion estimator A plurality of global motion vectors are derived from the motion vectors of a previous picture in a sequence, and the global motion vectors are analysed to determine motion characteristics The video encoding is arranged to enable switching among different types of local motion estimators based on the motion characteristics of the moving pictures sequence This gives rise to a motion estimation algorithm that can adaptively change its search range, search area and block matching scheme to suit different types of moving sequences

High-performance waveguide-integrated germanium PIN photodiodes for optical communication applications [Invited]

Abstract: This paper reports on high-performance waveguide-integrated germanium photodiodes for optical communications applications. 200 mm wafers and production tools were used to fabricate the devices. Yields over 97% were obtained for three different compact photodiodes (10×10 μm and intrinsic region width of 0.5, 0.7, and 1 μm) within the same batch of three wafers. Those photodiodes exhibit low dark currents under reverse bias with median values of 74, 62, and 61 nA for intrinsic widths of 0.5, 0.7, and 1 μm, respectively, over a full wafer. Responsivities up to 0.78 A/W at 1550 nm and zero bias were measured. Zero bias operation is possible for 25 and 40 Gbps with receiver sensitivity estimated to −13.9 and −12.3 dBm, respectively.