Silicon Labs

About: Silicon Labs is a company organization based out in Austin, Texas, United States. It is known for research contribution in the topics: Signal & Phase-locked loop. The organization has 1008 authors who have published 1667 publications receiving 21769 citations. The organization is also known as: Silicon Labs.

Subthreshold leakage modeling and reduction techniques

Abstract: As technology scales, subthreshold leakage currents grow exponentially and become an increasingly large component of total power dissipation. CAD tools to help model and manage subthreshold leakage currents will be needed for developing ultra low power and high performance integrated circuits. This paper gives an overview of current research to control leakage currents, with an emphasis on areas where CAD improvements will be needed. The first part of the paper explores techniques to model subthreshold leakage currents at the device, circuit, and system levels. Next, circuit techniques such as source biasing, dual Vt partitioning, MTCMOS, and VTCMOS are described. These techniques reduce leakage currents during standby states and minimize power consumption. This paper also explores ways to reduce total active power by limiting leakage currents and optimally trading off between dynamic and leakage power components.

On-chip antennas in silicon ICs and their application

Abstract: The feasibility of integrating antennas and required circuits to form wireless interconnects in foundry digital CMOS technologies has been demonstrated The key challenges including the effects of metal structures associated with integrated circuits, heat removal, packaging, and interaction between transmitted and received signals, and nearby circuits appear to be manageable This technology can potentially be applied for implementation of a true single-chip radio for general purpose communication, on-chip and inter-chip data communication systems, RFID tags, RF sensors/radars, and others

A 4-/spl mu/a quiescent-current dual-mode digitally controlled buck converter IC for cellular phone applications

Abstract: This paper describes a dual-mode digitally controlled buck converter IC for cellular phone applications. An architecture employing internal power management is introduced to ensure voltage compatibility between a single-cell lithium-ion battery voltage and a low-voltage integrated circuit technology. Special purpose analog and digital interface elements are developed. These include a ring-oscillator-based A/D converter (ring-ADC), which is nearly entirely synthesizable, is robust against switching noise, and has flexible resolution control, and a very low power ring-oscillator-multiplexer-based digital pulse-width modulation (PWM) generation module (ring-MUX DPWM). The chip, which includes an output power stage rated for 400 mA, occupies an active area 2 mm/sup 2/ in 0.25-/spl mu/m CMOS. Very high efficiencies are achieved over a load range of 0.1-400 mA. Measured quiescent current in PFM mode is 4 /spl mu/A.

Exploiting decentralized channel state information for random access

Abstract: We study the use of channel state information (CSI) for random access in fading channels. Traditionally, random access protocols have been designed by assuming simple models for the physical layer where all users are symmetric, and there is no notion of channel state. We introduce a reception model that takes into account the channel states of various users. Under the assumption that each user has access to its CSI, we propose a variant of Slotted ALOHA protocol for medium access control, where the transmission probability is allowed to be a function of the CSI. The function is called the transmission control. Assuming the finite user infinite buffer model we derive expressions for the maximum stable throughput of the system. We introduce the notion of asymptotic stable throughput (AST) that is the maximum stable throughput as the number of users goes to infinity. We consider two types of transmission control, namely, population-independent transmission control (PITC), where the transmission control is not a function of the size of the network and population-dependent transmission control (PDTC), where the transmission control is a function of the size of the network. We obtain expressions for the AST achievable with PITC. For PDTC, we introduce a particular transmission control that can potentially lead to significant gains in AST. For both PITC and PDTC, we show that the effect of transmission control is equivalent to changing the probability distribution of the channel state. The theory is then applied to code-division multiple-access (CDMA) networks with linear minimum mean-square error (LMMSE) receivers and matched filters (MF) to illustrate the effectiveness of using channel state. It is shown that through the use of channel state, with arbitrarily small power, it is possible to achieve an AST that is lower-bounded by the spreading gain of the network. This result has implications for the reachback problem in large sensor networks.

Communication Using Antennas Fabricated in Silicon Integrated Circuits

Abstract: The feasibility of integrating compact antennas and required circuits for implementing wireless interconnections in foundry digital CMOS technologies has been demonstrated. A 3-mm long zigzag dipole antenna on a 20-Omega-cm substrate should have efficiency up to approximately 25% at 24 GHz and cost 1-2 cents. These antennas can be used to implement a radio for 100-kb/s communication up to about 10 m. By lowering the operation frequency to 5.8 GHz and using a monopole structure, which occupies approximately 30% more area, the communication range can be increased by three times or more. This technology, as well as in a true single-chip radio, can be used for intra- and inter-chip data communication, intra- and inter-chip clock distribution, beacons, radars, RFID tags, and contactless high-frequency testing.