A novel fast lock-in phase-locked loop frequency synthesizer with direct frequency presetting circuit

This paper proposes a novel, fast lock-in, phase-locked loop (PLL) frequency synthesizer. The synthesizer includes a novel mixed-signal voltage-controlled oscillator (VCO) with a direct frequency presetting circuit. The frequency presetting circuit can greatly speed up the lock-in process by accurately the presetting oscillation frequency of the VCO. We fully integrated the synthesizer in standard 0.35 mu m, 3.3 V complementary metal-oxide-semiconductors (CMOS) process. The entire chip area is only 0.4 mm(2). The measured results demonstrate that the synthesizer can speed up the lock-in process significantly and the lock-in time is less than 10 mu s over the entire oscillation frequency range. The measured phase noise of the synthesizer is -85 dBc/Hz at 10 kHz offset. The synthesizer avoids the tradeoff between the lock-in speed and the phase noise/spurs. The synthesizer monitors the chip temperature and automatically compensates for the variation in frequency with temperature.

A direct digital frequency synthesizer with fourth-order phase domain Delta Sigma noise shaper and 12-bit current-steering DAC

This paper presents a direct digital frequency synthesizer (DDFS) with a 16-bit accumulator, a fourth-order phase domain single-stage Delta Sigma interpolator, and a 300-MS/s 12-bit current-steering DAC based on the Q(2) Random Walk switching scheme. The Delta Sigma interpolator is used to reduce the phase truncation error and the ROM size. The implemented fourth-order single-stage Delta Sigma noise shaper reduces the effective phase bits by four and reduces the ROM size by 16 times. The DDFS prototype is fabricated in a 0.35-mu m CMOS technology with active area of 1.11 mm(2) including a 12-bit DAC. The measured DDFS spurious-free dynamic range (SFDR) is greater than 78 dB using a reduced ROM with 8-bit phase, 12-bit amplitude resolution and a size of 0.09 mm(2). The total power consumption of the DDFS is 200)mW with a 3.3-V power supply.

The status, limits and countermeasures in the development of the silicon microelectronics industry

In this paper.. the status and limits in the development of the silicon microelectronics industry are presented briefly. The key countermeasures given are use of the new structure materials and the new device structures.

Effect of the implantation of fluorine on the mobility of channel electron for partially depleted SOI nMOSFET

The mobility of channel electron, for partially depleted Sol nMOSFET in this paper, decreases with the increase of implanted fluorine dose in buried oxide layer. But, the experimental results also show that it is larger for the transistor corresponding to the lowest implantation dose than no implanted fluorine in buried layer. It is explained in tern-is of a "lubricant" model. Mien fluorine atoms are implanted in the top silicon layer, the mobility is the largest. In addition, a positive shift of threshold voltage has also been observed for the transistors fabricated on the Sol wafers processed by the implantation of fluorine. The causes of all the above results are discussed.

VCSEL-based parallel optical transmission module

This paper describes the design process and performance of the optimized parallel optical transmission module. Based on 1x12 VCSEL (Vertical Cavity Surface Emitting Laser) array, we designed and fabricated the high speed parallel optical modules. Our parallel optical module contains a 1x12 VCSEL array, a 12 channel CMOS laser driver circuit, a high speed PCB (Printed Circuit Board), a MT fiber connector and a packaging housing. The L-I-V characteristics of the 850nm VCSEL was measured at the operating current 8mA, 3dB frequency bandwidth more than 3GHz and the optical output 1mW. The transmission rate of all 12 channels is 30Gbit/s, with a single channel 2.5Gbit/s. By adopting the integration of the 1x12 VCSEL array and the driver array, we make a high speed PCB (Printed Circuit Board) to provide the optoelectronic chip with the operating voltage and high speed signals current. The LVDS (Low-Voltage Differential Signals) was set as the input signal to achieve better high frequency performance. The active coupling was adopted with a MT connector (8 degrees slant fiber array). We used the Small Form Factor Pluggable (SFP) packaging. With the edge connector, the module could be inserted into the system dispense with bonding process.

Metal-free growth of Si/SiO2 nanowires by annealing SiOx (x < 2) films deposited by PECVD

A new metal catalysis-free method of fabricating Si or SiO2 nanowires (NWs) compatible with Si CMOS technology was proposed by annealing SiOx (x < 2) films deposited by plasma -enhanced chemical vapor deposition (PECVD). The effects of the Si content (x value) and thickness of SiOx films, the annealing process and flowing gas ambient on the NW growth were studied in detail. The results indicated that the SiOx film of a thickness below 300 rim with x value close to 1 was most favorable for NW growth upon annealing at 1000-1150 degrees C in the flowing gas mixture of N-2 and H-2. NWs of 50-100nm in diameter and tens of micrometers in length were synthesized by this method. The formation mechanism was likely to be related to a new type of oxide assisted growth (OAG) mechanism, with Si nanoclusters in SiOx films after phase separation serving as the nuclei for the growth of NWs in SiOx films > 200nm, and SiO molecules from thin SiO, film decomposition inducing the NW growth in films < 100nm. An effective preliminary method to control NW growth direction was also demonstrated by etching trenches in SiOx films followed by annealing.

A novel low-power input-independent MOS AC/DC charge pump

This paper presents a novel fully integrated MOS AC to DC charge pump with low power dissipation and stable output for RFID applications. To improve the input sensitivity, we replaced Schottky-diodes in conventional charge pumps with MOS diodes with zero threshold, which has less process defects and is thus more compatible with other circuits. The charge pump in a RFID transponder is implemented in a 0.35um CMOS technology with 0.24 sq mm die size. The analytical model of the charge pump and the simulation results are presented.

An Accurate and Fast Behavioral Model for PLL Frequency Synthesizer Phase Noise/Spurs Prediction

This paper presents a behavior model for PLL Frequency Synthesizer. All the noise sources are modeled with noise voltages or currents in time-domain. An accurate VCO noise model is introduced, including both thermal noise and 1/f noise. The behavioral model can be co-simulated with transistor level circuits with fast speed and provides more accurate phase noise and spurs prediction. Comparison shows that simulation results match very well with measurement results.

A Novel Architecture of Vision Chip for Fast Traffic Lane Detection and FPGA Implementation

This paper presents a novel architecture of vision chip for fast traffic lane detection (FTLD). The architecture consists of a 32*32 SIMD processing element (PE) array processor and a dual-core RISC processor. The PE array processor performs low-level pixel-parallel image processing at high speed and outputs image features for high-level image processing without I/O bottleneck. The dual-core processor carries out high-level image processing. A parallel fast lane detection algorithm for this architecture is developed. The FPGA system with a CMOS image sensor is used to implement the architecture. Experiment results show that the system can perform the fast traffic lane detection at 50fps rate. It is much faster than previous works and has good robustness that can operate in various intensity of light. The novel architecture of vision chip is able to meet the demand of real-time lane departure warning system.

A Novel 0.72-6.2GHz Continuously-Tunable Delta Sigma Fractional-N Frequency Synthesizer

This paper presents a wideband Delta Sigma-based fractional-N synthesizer with three integrated quadrature VCOs for multiple-input multiple-output (MIMO) wireless communication applications. It continuously covers a wide range frequency from 0.72GHz to 6.2GHz that is suitable for multiple communication standards. The synthesizer is designed in 0.13-um RE CMOS process. The dual clock full differential multi-modulus divide (MMD) with low power consumption can operate over 9GHz under the worst condition. In the whole range frequency from 0.72GHz to 6.2GHz, the maximal tuning range of the QVCOs reaches 33.09% and their phase noise is -119d8/Hz similar to 124d8/Hz @1MHz. Its current is less than 12mA at a 1.2V voltage supply when it operates at the highest frequency of 6.2GHz.

A Smart Frequency Presetting Technique for Fast Lock-in LC-PLL Frequency Synthesizer

This paper proposes a smart frequency presetting technique for fast lock-in LC-PLL frequency synthesizer. The technique accurately presets the frequency of VCO with small initial frequency error and greatly reduces the lock-in time. It can automatically compensate preset frequency variation with process and temperature. A 2.4GHz synthesizer with 1MHz reference input was implemented in 0.35 mu m CMOS process. The chip core area is 0.4mm(2). Output frequency of VCO ranges from 2390 to 2600MHz. The measured results show that the typical lock-in time is 3 mu s. The phase noise is -112dBc/Hz at 600KHz offset from center frequency. The test chip consumes current of 22mA that includes the consumption of the I/O buffers.

面向红外、紫外焦平面阵列的读出电路的研究

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Kondo effect in a triangular triple quantum dots ring with three terminals

For a triangular triple quantum dots (TTQDs) ring with three terminals, when lowering one of the dot-lead coupling to realize the left-right (L-R) reflection symmetry coupling, the internal C-upsilon of the TTQDs is well preserved in the absence of many-body effect for the symmetric distribution of the dot-lead coupling on the molecular orbits. In the presence of Kondo effect, the decrement of one of the dot-lead couplings suppresses the inter-dot hopping. This happens especially for the coupled quantum dot (QD), which decouples with the other two ones gradually to form a localized state near the Fermi level As a result, the internal dynamic symmetry of the TTQDs ring is reduced to L-R reflection symmetry, and simultaneously, the linear conductance is lifted for the new forming molecular orbit near the Fermi level

垂直结构金属基极有机晶体管及其在有机发光驱动中的应用

近几十年来，有机半导体材料作为新一代的信息功能材料正以其光电性能优异、生产成本低廉、加工工艺简单、选材范围宽广、机械性能柔软等显著的优点，吸引了世界范围内的目光，成为越来越多研究机构竞相研究和开发的对象，被广泛应用于发光二极管、薄膜晶体管、太阳能电池、存储器等光电子器件中。这些有机半导体器件的应用前景十分广阔，其巨大的商业价值极大地推动了有机半导体器件的发展。 本论文主要制备了N型金属基极有机晶体管，并对其性能进行了研究和分析，并在此基础上，研究了其在有机发光驱动中的应用。 (1) 用N型有机半导体材料Alq3、F16CuPc和BAlq3作发射极层，Au作为基极，N型硅作为收集极层，Al作为发射极接触电极成功地制备出了一系列N型无机/有机杂化金属基极晶体管，这些器件都表现出了良好的共基极增益特性，最大共基极增益达到了0.991，接近理想值1。在此基础上，通过在发射极层和发射极电极之间引入V2O5界面修饰层，还实现了具有良好共发射极特性的N型无机/有机杂化金属基极晶体管。研究发现，V2O5界面修饰层的引入明显地减小了共基极漏电流，使器件的共基极特性得到了进一步的改善，同时也使器件表现了共发射极特性，实现了电流的放大，我们已经把共基极特性的改善和共发射极特性的实现归功于界面修饰层的引入提高了电子注入的结果。 (2) 根据金属与半导体的接触理论,设计制备出了带有Au/Al双层金属基极的N型无机/有机杂化金属基极晶体管。由于Al和Alq3之间好的接触特性和有效的从Al到Alq3的空穴阻挡特性以及Au和Si之间良好的肖特基接触特性，大大降低了器件的漏电流，使器件在低的电压下表现了优异的共基极和共发射极特性，共基极增益达到了近似理想值1，最大共发射机增益达到了4000，克服了单层金属基极晶体管难实现共发射极特性的问题，为实现高性能金属基极晶体管提供了新的思路。 (3) 利用异质结的概念，设计制备出了带有BAlq3/Alq3异质结结构的N型无机/有机杂化金属基极晶体管，该器件同样表现了优异的共基极和共发射极特性。研究发现，同Alq3单发射极层结构的金属基极晶体管相比，BAlq3/Alq3异质结发射极层的使用进一步降低了器件的漏电流，使器件在相同的电压下表现了更高的输出电流和更高的共发射极增益，为进一步实现高性能金属基极晶体管提供了新的方法。 (4) 用有机半导体材料取代无机高掺杂硅作为收集极层，制备出了带有Al单层金属基极和Au/Al双层金属基极的N型垂直结构全有机金属基极晶体管，该器件表现出了良好的共基极特性和共发射极特性。研究表明，全有机金属基极晶体管表现了和无机/有机混合型金属基极晶体管相似的特性，其从本质上说也是一种渗透型金属基极晶体管。 (5) 实现了金属基极有机晶体管驱动有机发光二极管的集成器件。利用金属基极有机晶体管的共发射极电流放大特性，在基极输入电流IB量级比较低（uA）的情况下，得到了较大量级（mA）的输出电流IC，从而实现了对白光有机发光二极管的驱动，在基极输入电流IB为1×10-5A时有机发光二极管的亮度达到了1279 cd/m2。