Slave Output Research Articles

Design and verification of daisy chain serial peripheral interface using system Verilog and universal verification methodology

Serial peripheral interface (SPI) transfers the data between electronic devices like micro controllers and other peripherals. SPI consists of two control lines: select signal and clock signal, and two data lines: input and output. In single master-single slave, the communication is in between master and slave only which will make the design complex and costly, area will increase. In regular SPI mode, the number of chip-select lines is increased if the number of slaves increases. Due to this, the input data received by the master from the slaves are corrupted at master input slave output (MISO). The proposed daisy chain method is used to overcome this problem. The daisy chain method requires only one chip select line at master compared to the regular SPI mode. When the chip-select line is active low, all the slaves are active, and the clock is initiated to all the slaves to transfer the data from the master to the first slave through the master output slave input (MOSI). In this paper, the daisy-chain SPI is designed and developed using Verilog. The proposed design is verified using system Verilog (SV) and universal verification methodology (UVM) in QuestaSim.

Design, implementation, control and optimization of single stage pilot scale reverse osmosis process.

In this paper, a single-stage pilot-scale reverse osmosis (RO) process is considered. The process is mainly used in various chemical industries such as dye, pharmaceutical, beverage, and so on. Initially, mathematical modeling of the process is to be done followed by linearization of the system. Here a dual loop construction with a master and a slave is used. The slave uses the conventional proportional integral derivative (PID) with a reference model of the RO process and the master uses the fractional order proportional integral derivative (FOPID) with a real time RO process. The slave's output is compared with output of the real time RO process to obtain the error which is in turn used to tune the master. The slave controller is tuned using Ziegler Nichols method and the error criterion such as integral absolute error (IAE), integral squared error (ISE), integral time squared error (ITSE), integral time absolute error (ITAE) are calculated and the minimum among them was chosen as the objective function for the master loop tuning. Hence the tuning of the controller becomes a whole. Therefore two optimization techniques such as particle swarm optimization (PSO) and bacterial foraging optimization algorithm (BFO) are used for the tuning of the master loop. From the calculations, the ITSE had the minimum value among the performance indices, hence it was used as the objective function for the BFO and PSO. The best-tuned values will be obtained with the use of these techniques and the best among all can be considered for various industrial applications. Finally, the performance of the process is compared with both techniques and BFO outperforms the PSO from the simulations.

Optimal Design of Multi-Output LLC Resonant Converter with Independently Regulated Synchronous Single-Switched Power-Regulator

This paper presents a tightly regulated multi-output isolated converter that employs only an independently regulated synchronous Single-Switched Post-Regulator (SSPR). The proposed converter is a highly accurate single-ended secondary side post-regulator based on a Series Resonant Converter (SRC); furthermore, it has a voltage-doubler characteristic. The proposed post-regulator requires only one auxiliary switch, in contrast with a bulky and expensive non-isolated DC–DC converter. Moreover, the added voltage-doubler can tightly regulate the slave output current. In addition, the voltage-doubler can improve electromagnetic interference characteristics and reduce switching losses arising from the Zero Current Switching (ZCS) operation of all power switches. The validity of the proposed converter is verified using experimental results obtained via a prototype converter applicable to an LED 3D TV power supply.

Optical injection locking at sub nano-watt powers.

We demonstrate optical injection locking (OIL) at record low injection power of -65 dBm using EDFA-based pre-amplification and an electrical phase locked loop (PLL). Investigating the phase noise characteristics of OIL, we find that at low injection powers the slave laser linewidth and injection ratio strongly influence the phase noise of the locked slave output. By introducing an EDFA pre-amplifier, the minimum locking power for OIL is reduced. Moreover, using this pre-amplifier we find that there exists an optimum injection power into the slave where the output phase noise is minimized and is below the phase noise without EDFA. We evaluate an OIL-based pump recovery in a phase sensitive amplifier (PSA) receiver system aimed at free-space communications.

Output Current-Differential Control Scheme for Input-Series–Output-Parallel-Connected Modular DC–DC Converters

This paper proposes an output current-differential (OCD) control scheme that has a master–slave structure. It can be applied in dc/dc converters to connect the input in series and the output in parallel. All of the control and sample circuits in the proposed control scheme are on the output side, which means that there is no further isolation in the control loops. The proposed control scheme, consisting of one output voltage regulator loop and individual load-current-sharing loops, will enable low-voltage converters to be used for high-voltage specifications. The master module regulates the output voltage through a common output voltage loop and provides current references to slave modules. The individual current-sharing loops residing in the slave modules regulate the current in each module equally. According to the power balance, input-voltage sharing is realized simultaneously. To prevent a situation in which system failure is caused by master module failure, a fault-tolerant automatic master–slave output current-differential (FOCD) control scheme is developed. The performance of the OCD and FOCD control schemes is validated on a 450-W prototype input-series–output-parallel system comprising three forward converters.

Cooperative output regulation of linear multi-agent network systems with dynamic edges

This paper investigates a class of linear multi-agent network systems, in which nodes are coupled by dynamic edges in the sense that each edge has a dynamic system attached as well. The outputs of the edge dynamic systems form the external inputs of the node dynamic systems, which are termed neighboring inputs representing the coupling actions between nodes. The outputs of the node dynamic systems are the inputs of the edge dynamic systems. Several cooperative output regulation problems are posed, including output synchronization, output cooperation and master–slave output cooperation. Output cooperation is specified as making the neighboring input, a weighted sum of edge outputs, track a predefined trajectory by cooperation of node outputs. Distributed cooperative output regulation controllers depending on local states and neighboring inputs are presented, which are designed by combining feedback passivity theories and the internal model principle. A simulation example on the cooperative current control of an electrical network illustrates the potential applications of the analytical results.

Function vector synchronization based on fuzzy control for uncertain chaotic systems with dead‐zone nonlinearities

In this article, a fuzzy adaptive control scheme is designed to achieve a function vector synchronization behavior between two identical or different chaotic (or hyperchaotic) systems in the presence of unknown dynamic disturbances and input nonlinearities (dead‐zone and sector nonlinearities). This proposed synchronization scheme can be considered as a generalization of many existing projective synchronization schemes (namely the function projective synchronization, the modified projective synchronization, generalized projective synchronization, and so forth) in the sense that the master and slave outputs are assumed to be some general function vectors. To practically deal with the input nonlinearities, the adaptive fuzzy control system is designed in a variable‐structure framework. The fuzzy systems are used to appropriately approximate the uncertain nonlinear functions. A Lyapunov approach is used to prove the boundedness of all signals of the closed‐loop control system as well as the exponential convergence of the corresponding synchronization errors to an adjustable region. The synchronization between two identical systems (chaotic satellite systems) and two different systems (chaotic Chen and Lü systems) are taken as two illustrative examples to show the effectiveness of the proposed method. © 2015 Wiley Periodicals, Inc. Complexity 21: 234–249, 2016

Design and Simulation of Synchronization Control for a Dual-Output Forward Converter

Since high utilization and high output efficiency of forward converter transformer, it is often used in multiple-output DC voltage occasions. But the cross regulation in multiple outputs has affected the performance of forward converter. For this problem, a synchronization control model for a dual-output forward converter is proposed in this paper. That is, the master output is identified by calculating the desired power of dual outputs, and the other is the slave. Then it controls duty cycle of primary switch and master rectifying switch by employing closed-loop PID voltage-mode control. Simultaneously, it is to control duty cycle of rectifying switch in the slave by comparing sampled voltage with desired voltage. Simulation results demonstrate that cross-regulation problems can be solved effectively by this control method, and get a higher voltage accuracy of master output and slave output.

PFM/PWM 듀얼 모드 피드백 기반 LED BLU 구동용 LLC 공진 변환 제어 IC 설계

본 논문은 Pulse Frequency Modulation(PFM)/Pulse Width Modulation(PWM) 듀얼 모드 피드백 기반 LED 백라이트 유닛 구동용 LLC 공진 변환 제어 IC 설계에 대한 내용을 제시한다. 공진형 변환기에서 하나의 변압기를 사용하면서, 두 가지 출력 전압을 생성할 수 있는 구조를 제안하였으며, Master 출력은 PFM 방식으로 Slave 출력은 PWM 방식으로 제어하도록 설계 하였다. 2차 측 Master 출력을 제어하기 위해서 파워 스위치 제어 신호의 주파수를 조절하는 PFM 피드백과 2차 측 Slave 출력을 제어하기 위해서 파워 스위치 제어 신호의 펄스 폭을 조절하는 PWM 피드백 회로를 설계하였다. 설계된 IC는 <TEX>$0.35{\mu}m$</TEX> 2 Poly 3 Metal BCD(Bipolar-CMOS-DMOS) 공정을 이용하여 레이아웃 되었으며, 면적은 <TEX>$2.3mm{\times}2.2mm$</TEX> 이다. 또한, 설계한 칩은 5 V 공급 전압으로부터 26 mA의 전류를 소모하였다. This paper presents a design of LLC resonant converter IC for LED backlight unit based on PFM/PWM dual-mode feedback. Dual output LLC resonant architecture with a single inductor is proposed, where the master output is controlled by the PFM and slave output is controlled by the PWM. To regulate the master output PFM is used as feedback to control the frequency of the power switch. On the other hand, PWM feedback is used to control the pulse width of the power switch and to regulate the slave output. This chip is fabricated in 0.35um 2P3M BC(Bipolar-CMOS-DMOS) Process and the die area is <TEX>$2.3mm{\times}2.2mm$</TEX>. Current consumptions is 26mA from 5V supply.

The Design of a Low Cost CANopen Slave Node Based on STC90C514RD

CANopen is a kind of higher layer protocol based on CAN, and it is widely used in industrial automation field, especially in distributed motion control systems. The paper presents an approach of realizing CANopen slave node. Microcontroller STC90C514RD is used as a core chip to design the control system; the design adopts CTM1050 as the CAN transceiver and uses SJA1000 as the CAN controller. And the system consists of a CANopen slave node, input module and output module. MicroCANopen, which is an open source protocol stack of CANopen, is transplanted to main controller so that the function of CANopen could be implemented. Moreover the experimental platform is built to test the design of the system. The results prove that the design is feasible and valid.

Soft Switched Multi-Output PWM DC-DC Converter

In this paper, a new soft switched cell that overcomes most of the drawbacks of the normal hard switched-pulse width modulation converter is proposed to contrive a new family of soft switched PWM converters. All of the semiconductor devices in this converter are turned on and off under exact or near zero voltage switching (ZVS) and/or zero current switching (ZCS). No additional voltage and current stresses on the main switch and main diode occur. A push-pull converter equipped with the proposed snubber cell is analyzed in detail. The predicted operation principles and theoretical analysis of the presented converter are verified with a prototype of a 50W PWM push-pull multi-output converter with insulated MOSFET and for regulation of slave outputs magnetic amplifier post regulators are considered as post regulators. Moreover; this multioutput converter has a simple structure, low cost, and ease of control circuitry. DOI: http://dx.doi.org/10.11591/ijpeds.v3i3.4024

A high-power 626 nm diode laser system for Beryllium ion trapping

We describe a high-power, frequency-tunable, external cavity diode laser system near 626 nm useful for laser cooling of trapped (9)Be(+) ions. A commercial single-mode laser diode with rated power output of 170 mW at 635 nm is cooled to ≈-31°C, and a single longitudinal mode is selected via the Littrow configuration. In our setup, involving two stages of thermoelectric cooling, we are able to obtain ≈130 mW near 626 nm, sufficient for efficient frequency doubling to the required Doppler cooling wavelengths near 313 nm in ionized Beryllium. In order to improve nonlinear frequency conversion efficiency, we achieve larger useful power via injection locking of a slave laser. In this way the entirety of the slave output power is available for frequency doubling, while analysis may be performed on the master output. We believe that this simple laser system addresses a key need in the ion trapping community and dramatically reduces the cost and complexity associated with Beryllium ion trapping experiments.

A Dual-Output Integrated LLC Resonant Controller and LED Driver IC with PLL-Based Automatic Duty Control

This paper presents a secondary-side, dual-mode feedback LLC resonant controller IC with dynamic PWM dimming for LED backlight units. In order to reduce the cost, master and slave outputs can be generated simultaneously with a single LLC resonant core based on dual-mode feedback topologies. Pulse Frequency Modulation (PFM) and Pulse Width Modulation (PWM) schemes are used for the master stage and slave stage, respectively. In order to guarantee the correct dual feedback operation, Phased-Locked Loop (PLL)-based automatic duty control circuit is proposed in this paper. The chip is fabricated using <TEX>$0.35{\mu}m$</TEX> Bipolar-CMOS-DMOS (BCD) technology, and the die size is <TEX>$2.5mm{\times}2.5mm$</TEX>. The frequency of the gate driver (GDA/GDB) in the clock generator ranges from 50 to 425 kHz. The current consumption of the LLC resonant controller IC is 40 mA for a 100 kHz operation frequency using a 15 V supply. The duty ratio of the slave stage can be controlled from 40% to 60% independent of the frequency of the master stage.

Anticipated synchronization and the predict-prevent control method in the FitzHugh-Nagumo model system

We study the synchronization region of two unidirectionally coupled FitzHugh-Nagumo systems, in a master-slave configuration, under the influence of external forcing terms. In the particular region where the slave anticipates the dynamics of the master system, we observe that the synchronization is robust to the different types of forcings. We then use the predict-prevent control method to suppress unwanted pulses in the master system by using the information of the slave output. We find that this method is more efficient than the direct control method based on the master dynamics. Finally, we observe that a perfect matching between the parameters of the master and the slave is not necessary for the control to be efficient. Moreover, this parameter mismatch can, in some cases, improve the control.

LLC 공진형 컨버터를 이용한 독립제어 가능한 2 채널 LED 구동회로

The independently regulated dual-output LLC resonant converter using only one power stage and one control IC is proposed in this paper. The conventional dual-output LLC resonant converter requires the extra non-isolated DC/DC converter to obtain the tightly regulated slave output voltage, which results in the low power conversion efficiency and high production costs. On the other hand, since the proposed converter controls the master and slave output voltages by pulse width modulation(PWM) and pulse frequency modulation(PFM), it can achieve tightly regulated dual output voltages without the additional non-isolated DC/DC converter. Therefore, it features a high efficiency and low cost. To confirm the validity of the proposed converter, theoretical analysis and experimental results from a 40W LED driver prototype are presented.

Phase-coherent repetition rate multiplication of a mode-locked laser from 40 MHz to 1 GHz by injection locking

We have used injection locking to multiply the repetition rate of a passively mode-locked femtosecond fiber laser from 40 MHz to 1 GHz while preserving optical phase coherence between the master laser and the slave output. The system is implemented almost completely in fiber and incorporates gain and passive saturable absorption. The slave repetition rate is set to a rational harmonic of the master repetition rate, inducing pulse formation at the least common multiple of the master and slave repetition rates.

Wideband and high-gain frequency stabilization of a 100-W injection-locked Nd:YAG laser for second-generation gravitational wave detectors

Second-generation gravitational wave detectors require a highly stable laser with an output power greater than 100 W to attain their target sensitivity. We have developed a frequency stabilization system for a 100-W injection-locked Nd:YAG (yttrium aluminum garnet) laser. By placing an external wideband electro-optic modulator used as a fast-frequency actuator in the optical path of the slave output, we can circumvent a phase delay in the frequency control loop originating from the pole of an injection-locked slave cavity. Thus, we have developed an electro-optic modulator made of a MgO-doped stoichiometric LiNbO(3) crystal. Using this modulator, we achieve a frequency control bandwidth of 800 kHz and a control gain of 180 dB at 1 kHz. These values satisfy the requirement for a laser frequency control loop in second-generation gravitational wave detectors.

Accounting in service to racism: monetizing slave property in the antebellum South

The contemporary scene in accounting history features a growing interest in the “suppressed voices” that have been systematically excluded from the processes of accounting. Notwithstanding, the bulk of critical studies on disenfranchised groups has focused on gender issues, suppressed economic classes, and the roadblocks encountered by ethnic minorities attempting to enter the accounting profession. The few papers that have chronicled the use of accounting on slave plantations have viewed these techniques as essentially unproblematic, neutral conveyances of information needed by decision makers. This paper adopts a more critical perspective of accounting’s past and uses plantation records to examine its particular role in the commoditization, objectification, and dehumanization of an entire class of people. Its overriding purpose is not to examine the economics (i.e., viability or profitability) of slavery, but rather to illustrate how accounting practices of measurement, valuation, and classification served slave owners and sustained slavery’s institutions. We readily acknowledge that neither accounting nor accountants constructed slavery, but we do believe that accounting practices reinforced racially based social relationships by converting slave exchanges, holdings, and outputs into monetary terms while completely ignoring the qualitative, human dimension of slavery.

반도체 레이저의 Side-band Injection-Locking을 이용한 광학적 60 GHz 신호 생성

Master laser(ML)의 직접 변조로 생성된 여러 개의 side-bands 중 두 개의 target band게 두 개의 Slave laser(SL)가 각각 lock이 되도록 하는 side-band injection-locking 방법을 이용하여 광학적 60㎓의 밀리미터파 신호를 구현하였다 ML에 lock이 된 두 SL의 output들은 photo detection시 서로 beating하여 안정적이고 매우 깨끗한 60㎓ 신호를 생성하였다. Optical 60 ㎓ millimeter-wave (MMW) signal generation is demonstrated using the sideband injection-locking method in the master/slave configuration, where two slave lasers are locked to two among several side-bands produced by the direct rf-modulation of a master laser. These two locked slave laser outputs beat against each other in the photo-detector and produce stable and very pure 60 ㎓ signals.

Comparison of five high speed bistables by computer simulation

The paper describes five different emitter-coupled logic (ECL) bistable designs and their comparison, both in the divide by 2 and transmission modes of operation, using computer simulation techniques. By adopting a single transistor model, performance differences due to processing variations have been eliminated. Factors affecting the operating rate of a bistable are discussed, and the simulations show one design to have the fastest maximum toggle frequency of 920 MHz, and a different one the shortest average slave output transition time of 400 ps. The optimum design is a balanced bistable with single emitter follower level shifting between stages. This has been fabricated using the BTRL ECL 40 process, and measurements show that the maximum transmission rate is 1 Gbit/s.