Rm mV Research Articles

A 20 Gb/s 0.4 pJ/b Energy-Efficient Transmitter Driver Utilizing Constant-<inline-formula> <tex-math notation="LaTeX">${\rm G}_{\rm m}$ </tex-math> </inline-formula> Bias

This paper describes a transmitter driver based on a CMOS inverter with a resistive feedback. By employing the proposed driver topology, the pre-driver can be greatly simplified, resulting in a remarkable reduction of the overall driver power consumption. It also offers another advantage that the implementation of equalization is straightforward, compared with a conventional voltage-mode driver. Furthermore, the output impedance remains relatively constant while the data is being transmitted, resulting in good signal integrity. For evaluation of the driver performance, a fully functional 20 Gb/s transmitter is implemented, including a PRBS generator, a serializer, and a half-rate clock generator. In order to enhance the overall speed of the digital circuits for 20 Gb/s data transmission, the resistive feedback is applied to the time-critical inverters, which enables shorter rise/fall times. The prototype chip is fabricated in a 65 nm CMOS technology. The implemented driver circuit operates up to the data rate of 20 Gb/s, exhibiting an energy efficiency of 0.4 pJ/b for the output swing of 250 ${\rm mV}_{\mathrm {pp,diff}}$ .

A Categorical Equivalence Motivated by Kalman’s Construction

An equivalence between the category of MV-algebras and the category $${{\rm MV^{\bullet}}}$$MV? is given in Castiglioni et al. (Studia Logica 102(1):67---92, 2014). An integral residuated lattice with bottom is an MV-algebra if and only if it satisfies the equations $${a = \neg \neg a, (a \rightarrow b) \vee (b\rightarrow a) = 1}$$a=¬¬a,(a?b)?(b?a)=1 and $${a \odot (a\rightarrow b) = a \wedge b}$$a?(a?b)=a?b. An object of $${{\rm MV^{\bullet}}}$$MV? is a residuated lattice which in particular satisfies some equations which correspond to the previous equations. In this paper we extend the equivalence to the category whose objects are pairs (A, I), where A is an MV-algebra and I is an ideal of A.

A 40 Gb/s Monolithically Integrated Linear Photonic Receiver in a <formula formulatype="inline"><tex Notation="TeX">$0.25~\mu {\rm m}$</tex></formula> BiCMOS SiGe:C Technology

This letter presents the first 40 Gb/s monolithically integrated silicon photonics linear receiver (Rx) comprising a germanium photodiode (Ge-PD) and a linear transimpedance amplifier (TIA). Measured optical-electrical (O/E) 3 dB bandwidth (BW) of the Rx is 31 GHz. At 40 Gb/s, the Rx achieves a sensitivity of $-3~{\rm dBm}$ average optical input power with BER of $2.5\times 10^{-11}$ . It operates at $\lambda =1.55 ~\mu{\rm m}$ wavelength, uses 3.3 and 3.7 V power supplies, dissipates 275 mW of power, provides maximum differential output amplitude of $500 ~{\rm mV}_{\rm pp}$ , and occupies an area of $3.2~{\rm mm}^{2}$ . The presented receiver achieves the highest bit rate among the published work in monolithically integrated silicon photonics receivers.

Design Methodology of Subthreshold Three-Stage CMOS OTAs Suitable for Ultra-Low-Power Low-Area and High Driving Capability

A design methodology for three-stage CMOS OTAs operating in the subthreshold region is presented. The procedure is focused on the development of ultra-low-power amplifiers requiring low silicon area but being able to drive high capacitive loads. Indeed, by following the presented methodology we designed a CMOS OTA in a 0.35- $\mu{\rm m}$ technology that occupies only $4.4\cdot 10^{-3} {\rm mm}^{2}$ , is powered with a 1-V supply, exhibits 120-dB DC gain and is able to drive a capacitive load up to 200 pF. Thanks to proposed methodology, the OTA is able to provide a 20-kHz unity gain bandwidth while consuming 195 nW, even under the high load considered. Moreover, the slew rate enhancer circuit in addition to the class AB output stage allows an average slew rate higher than 5 ${\rm mV}/\mu{\rm s}$ with the 200 pF load. Comparison with prior art shows an improvement factor in the figures of merit higher than 5.

Current-Mode Synthetic Control Technique for High-Efficiency DC–DC Boost Converters Over a Wide Load Range

This paper proposes a current-mode synthetic control (CSC) technique for the design of boost converters to overcome the difficulty in designing a current-ripple hysteresis boost converter and to maintain high conversion efficiency over a wide load range. The CSC technique has a high accuracy because of the additional voltage path through the error amplifier. A smooth load transient response is maintained when the operation transits from continuous conduction mode with a nearly constant switching frequency to discontinuous conduction mode with a load-dependent switching frequency. Generally, ripple performance, light-load efficiency, and switching frequency are traded off in the design of hysteresis control regulator. In this paper, a balance among the load-dependent switching frequencies at light loads results in high power conversion efficiency compared with conventional pulsewidth modulation converter and attains compact ripple performance. The experimental results show that the output voltage ripple can be kept ${<;}{\rm 50}~{\rm mV}$ over a wide load current range from 10 to 400 mA, where as power conversion efficiency is maintained at 78% at a load current of 10 mA when the switching frequency is decreased from 5 to 2 MHz.

Approaching the Trap-Free Limit in Organic Single-Crystal Field-Effect Transistors

Crystalline organic semiconductors, bonded by weak van der Waals forces, exhibit macroscopic properties that are very similar to those of inorganic semiconductors. While there are many open questions concerning the microscopic nature of charge transport, minimizing the density of trap states (trap DOS) is crucial to elucidate the intrinsic transport mechanism. We explore the limits of state-of-the-art organic crystals by measuring single crystalline rubrene field-effect transistors that show textbook like transfer characteristics, indicating a very low trap DOS. Particularly, the high purity of the crystals and the very clean interface to the gate dielectric are reflected in an unprecedentedly low subthreshold swing of 65 ${\rm mV / decade}$, remarkably close to the fundamental limit of $58.5 {\rm mV / decade}$. From the measured subthreshold behavior we have consistently quantified the trap DOS by two different methods, yielding an exceedingly low trap density of $D_{bulk} = 1 \times 10^{13}~{\rm cm^{-3}eV^{-1}}$ at an energy of $\sim0.62~{\rm eV}$. These numbers correspond to one trap per eV in $10^8$ rubrene molecules. The equivalent density of traps located at the interface is $D_{it} = 3 \times 10^{9}~{\rm cm^{-2}eV^{-1}}$ which puts them on par with the best crystalline ${\rm SiO_2/Si}$ field-effect transistors.

Design Expressions for the Magnetically Insulated Line Oscillator

In this paper, a simple compact magnetically insulated line oscillator (MILO) design methodology, simulation, and optimization are described the MILO device combines the technologies of magnetically insulted electron flow with the slow-wave structure, and the device operates at a wide range of voltage $(0.1~{\rm MV}\leq{\rm V}\leq 1~{\rm MV})$ . The authors present the design methodology for a load-limited MILO device of a desired oscillation frequency, radio-frequency (RF) power, and applied dc voltage. An S-band MILO is designed and simulated using commercial particle-in-cell code MAGIC, for 600-kV dc voltage and 35-kA beam current. The simulated value for RF power is found to be in agreement with the designed value within 5% and an average output power of 1.05 GW at designed 2.725-GHz frequency is obtained.

A 0.47–0.66 pJ/bit, 4.8–8 Gb/s I/O Transceiver in 65 nm CMOS

A low-power forwarded-clock I/O transceiver architecture is presented that employs a high degree of output/input multiplexing, supply-voltage scaling with data rate, and low-voltage circuit techniques to enable low-power operation. The transmitter utilizes a 4:1 output multiplexing voltage-mode driver along with 4-phase clocking that is efficiently generated from a passive poly-phase filter. The output driver voltage swing is accurately controlled from 100–200 ${\rm mV}_{\rm ppd}$ using a low-voltage pseudo-differential regulator that employs a partial negative-resistance load for improved low frequency gain. 1:8 input de-multiplexing is performed at the receiver equalizer output with 8 parallel input samplers clocked from an 8-phase injection-locked oscillator that provides more than 1UI de-skew range. In the transmitter clocking circuitry, per-phase duty-cycle and phase-spacing adjustment is implemented to allow adequate timing margins at low operating voltages. Fabricated in a general purpose 65 nm CMOS process, the transceiver achieves 4.8–8 Gb/s at 0.47–0.66 pJ/b energy efficiency for ${\rm V}_{\rm DD}=0.6$ –0.8 V.

Intensity-Encoded Polymer Optical Fiber Accelerometer

In this paper, we report the development and experimental implementation of a low-cost, compact, intensity-encoded accelerometer based on polymer optical fibers (POF). The proposed accelerometer sensor element relies on the misalignment between two POFs, being the external acceleration encoded in the optical signal intensity. The accelerometer performance was optimized by simulation, resulting in a coupling efficiency and modulation index values of 0.38 and 1.78, respectively. The implemented device has a sensitivity of ${\rm 33.5}\pm{\rm 0.1}~{\rm mV}/{\rm g}$ and a resonant frequency of ${\rm 51.44}\pm{\rm 0.1}~{\rm Hz}$ , obtained for a signal to noise ratio of 20 dB. This value for the resonant frequency is suitable for applications in several fields, such as structural health monitoring of civil engineering structures.

Evaluation of the uniform current density assumption in cathodic protection systems with close anode‐to‐cathode arrangement

AbstractCathodic protection modelling often involves making assumptions about geometric features and material characteristics that directly impact accuracy of solutions. In the present paper, predictive power of the model using approximate uniform current boundary condition on the cathode is validated against the model using nonlinear cathode polarization curves representative of low‐carbon steel structure of common geometry, buried in soil or immersed in seawater. In order to explore the worst case scenario, the present example deals with a large diameter pipeline (Ø 1.2 m) and a wire anode (Ø 0.05 m), separated by a distance d, both embedded in an infinite space of conductivity κ. The calculation is performed for the two sets of parameters – κ and limiting current density of oxygen reduction, il. For simulation of CP systems in seawater κ = 4.79 S/m and il = −86 µA/cm2 and for CP system in soil, κ = 10−3 S/m and il = −1.1 µA/cm2. The other physical parameters were identical for both systems (Tafel slopes ba = 60 mV/dec, bc = 120 mV/dec and equilibrium potentials $\phi _{\rm e}^{\rm a} = - 700\,{\rm mV}$, $\phi _{\rm c}^{\rm a} = - 800\,{\rm mV}$). The results were visualized to best exemplify the general trends in potential and current distributions that appear upon switch between uniform and nonlinear cathodic boundary conditions.

Modal operators on bounded residuated $\rm l$-monoids

Bounded residuated lattice ordered monoids (${\rm R\ell}$-monoids) form a class of algebras which contains the class of Heyting algebras, i.e.\ algebras of the propositional intuitionistic logic, as well as the classes of algebras of important propositional fuzzy logics such as pseudo $\mathop{\rm MV}$-algebras (or, equivalently, $\mathop{\rm GMV}$-algebras) and pseudo $\mathop{\rm BL}$-algebras (and so, particularly, $\mathop{\rm MV}$-algebras and $\mathop{\rm BL}$-algebras). Modal operators on Heyting algebras were studied by Macnab (1981), on $\mathop{\rm MV}$-algebras were studied by Harlenderová and Rachůnek (2006) and on bounded commutative ${\rm R\ell}$-monoids in our paper which will apear in Math. Slovaca. Now we generalize modal operators to bounded ${\rm R\ell}$-monoids which need not be commutative and investigate their properties also for further derived algebras.

Electrochemical and Spectroscopic Properties of Fly Ash–Polyaniline Matrix Nanorod Composites

Polyaniline (PANI) nanocomposites were prepared with fly ash (FA) either by aging the starting materials (aniline and FA) before oxidative polymerisation or by including poly(styrene sulphonic acid) (PSSA) eliminating the aging step. The aging procedure formed polymer nanotubes that have cross-sectional diameters of 50–110 nm. The procedure involving PSSA produced nanorods and nanofibres composites that have diameters of 100–500 nm and length of up to 10 µm attributed to the presence of metal oxides and silica in FA. The electrochemical analysis of the PANI–PSSA–FA nanorod composites shows three redox couples with formal potentials, \(\rm {E}{^{0'}}_{(200\,{\rm mV}\,{\rm s}^{-1})}\), values of 105 mV, 455 mV and 670 mV, and conductance, C, value of 1.21 × 10−2 S. The UV-Vis spectroscopy of the polymeric nanorod shows absorption maxima at 340 and 370 nm (due to π–π* transition of the benzoid rings), and 600–650 nm (due to charge transfer excitons of the quinoid structure), which are characteristic of emeraldine base.

AGE AND GENDER RESPONSES TO STRENGTH TRAINING

1527 Previous reports have concluded that muscle hypertrophic response to strength training (ST) is attenuated with age, but unaffected by gender. However, these comparisons have not been adequately addressed. To determine age and gender responses to ST, we studied the effects of a 9 wk unilateral, knee extensor ST program on both the trained and untrained quadriceps muscle group in 44 young (20-30 yr) and older (65-75yr) men and women. Muscular strength, thigh fat free mass (FFM), and total volume of the quadriceps muscle group (MV) were measured by 1 RM, DEXA, and MRI, respectively, in the trained and untrained legs of 11 young men, 11 young women, 11 older men, and 11 older women. Four sets of heavy resistance exercise was performed 3 times/wk on a Keiser K-300 leg extension machine. A 2x2 factorial ANOVA was used to determine age and gender effects using the difference between the changes in the trained and untrained legs. The ST program increased 1 RM strength, thigh FFM, and MV significantly more in the trained leg than in the untrained leg(all P < 0.05) for all age and gender groups. There was also a greater increase in both thigh FFM and MV in the young men compared to the young women(P < 0.05), and a greater increase in thigh FFM in the older men compared to the older women (P < 0.05). There were no significant differences in the increases of either thigh FFM or MV between the older and younger groups. Thus, in contrast to previous reports, these results show that the hypertrophic response to ST is greater in men than in women, but is not attenuated by age.