Bulk-driven non-equilibrium phase transitions in a mesoscopic ring

We study a periodic one-dimensional exclusion process composed of a driven and a diffusive part. In a mesoscopic limit where both dynamics compete we identify bulk-driven phase transitions. We employ mean-field theory complemented by Monte-Carlo simulations to characterize the emerging non-equilibrium steady states. Monte-Carlo simulations reveal interesting correlation effects that we explain phenomenologically.Comment: 4 pages, 3 figure

Self-Organized Criticality in a Bulk Driven One-Dimensional Deterministic System

We introduce a deterministic self-organized critical system that is one dimensional and bulk driven. We find that there is no universality class associated with the system. That is, the critical exponents change as the parameters of the system are changed. This is in contrast with the boundary driven version of the model [M. de Sousa Vieira, Phys. Rev. E 61 (2000) 6056] in which the exponents are unique. This model can be seen as a discretized version of the conservative limit of the Burridge-Knopoff model for earthquakes.Comment: In honor of Constantino Tsallis in the celebration of his 60th birthday (5 pages, 3 figures)- corrected typo

Bulk-driven flipped voltage follower

A voltage buffer so-called the bulk-driven flipped voltage follower is presented. This proposal is based on the flipped voltage follower (FVF) technique, but a bulk-driven MOSFET with the replica-biased scheme is utilized for the input device to eliminate the DC level shift. The proposed buffer has been designed and simulated with a 0.35 mum CMOS technology. The input current and capacitance of our proposal are 1.5 pA and 9.3 fF respectively, and with 0.8 V peak-to-peak 500 kHz input, the total harmonic distortion is 0.5% for a 10 pF load. This circuit can operate from a single 1.2 V power supply and consumes only 2.5 muA

Duality symmetries in driven one-dimensional hopping models

We consider some duality relations for models of non-interacting particles hopping on disordered one-dimensional chains. In particular, we discuss symmetries of bulk-driven barrier and trap models, and relations between boundary-driven and equilibrium models with related energy landscapes. We discuss the relationships between these duality relations and similar results for interacting many-body systems.Comment: 11 pages, 3 fig

Scaling the bulk-driven MOSFET into deca-nanometer bulk CMOS technologies

The International Technology Roadmap for Semiconductors predicts that the nominal power supply voltage, VDD, will fall to 0.7 V by the end of the bulk CMOS era. At that time, it is expected that the long-channel threshold voltage of a MOSFET, VT0, will rise to 35.5% of VDD in order to maintain acceptable off-state leakage characteristics in digital systems. Given the recent push for system-on-a-chip integration, this increasing trend in VT0/VDD poses a serious threat to the future of analog design because it causes traditional analog circuit topologies to experience progressively problematic signal swing limitations in each new process generation. To combat the process-scaling-induced signal swing limitations of analog circuitry, researchers have proposed the use of bulk-driven MOSFETs. By using the bulk terminal as an input rather than the gate, the bulk-driven MOSFET makes it possible to extend the applicability of any analog cell to extremely low power supply voltages because VT0 does not appear in the device\u27s input signal path. Since the viability of the bulk-driven technique was first investigated in a 2 um p-well process, there have been numerous reports of low-voltage analog designs incorporating bulk-driven MOSFETs in the literature - most of which appear in technologies with feature sizes larger than 0.18 um. However, as of yet, no effort has been undertaken to understand how sub-micron process scaling trends have influenced the performance of a bulk-driven MOSFET, let alone make the device more adaptable to the deca-nanometer technologies widely used in the analog realm today. Thus, to further the field\u27s understanding of the bulk-driven MOSFET, this dissertation aims to examine the implications of scaling the device into a standard 90 nm bulk CMOS process. This dissertation also describes how the major disadvantages of a bulk-driven MOSFET - i.e., its reduced intrinsic gain, its limited frequency response and its large layout area requirement - can be mitigated through modifications to the device\u27s vertical doping profile and well structure. To gauge the potency of the proposed process changes, an optimized n-type bulk-driven MOSFET has been designed in a standard 90 nm bulk CMOS process via the 2-D device simulator, ATLAS

Low voltage, low power, bulk-driven amplifier

The importance of low voltage and low powered electronics is increasing with advances in medical electronics. This branch of electronics specifically requires low voltage and low power to make efficient innovative medical equipment. Low power electronics are also desirable because it conserves energy and power. This paper proposes a design of a differential in - differential our amplifier that uses a bulk-driven differential pair for the input pair. In addition, it also used bulk-driven current mirrors for the tail current sink and the active loads. The bulkdriven technique helps to achieve the low voltage design. 90nm CMOS technology was considered for the design but at the end SIGE 5AM process was chosen as it has low threshold voltage values maintaining good current - voltage characteristics. The software Cadence was used to simulate the design. A layout of the amplifier is out of the scope of this paper. A gain of 14 dB was achieved using a rail-to-rail voltage of 1V (0.5V to -0.5). The power dissipation was 102uW using 5pF capacitive loads. The values of the calculations match the values of the simulations quite well. Some of the differences can be explained by the lack of accurate knowledge of the some of the process parameters for the SIGE 5AM process. Overall, the design achieved its goals and a successful low voltage and low power fully differential amplifier was created with respectable gain. This amplifier can be used as an input stage for an operational amplifier