An embedded current amplifier compensation (ECAC) for three-stage amplifiers with large capacitive loads is presented in this paper. Two current amplifiers are embedded into the first stage. The compensation capacitor is connected to the input of the current amplifier rather than the output of the first stage, which enables the non-dominant complex poles of the ECAC amplifier to be located at high frequencies for bandwidth extension; in addition, the compensation capacitor required is greatly reduced. The amplifier has been fabricated in a 0.13 µm CMOS process. When driving a 2000 pF capacitive load, the ECAC amplifier achieves 1.85 MHz gain-bandwidth product by dissipating 33.6 µW power at 1.2 V supply and using total compensation capacitance of only 0.8 pF.
Mode-evolutional serial branching mode multi/demultiplexer (SBMM) for homogeneous coupled multi-core fiber was demonstrated. This multi/multiplexer has some advantages such as the high fabrication tolerance and small wavelength and polarization dependences owing to the principle of adiabatic mode-evolutional phenomenon. The SBMM was fabricated using polymer materials. The selective four mode excitation with the low crosstalk of less than −10 dB and small wavelength dependence were realized within the CL-band.
Multi-core 3D IC is a new solution for greater quantity of cores, but with critical challenge of internal thermal. The interlayer cooling system is introduced for this problem, and expends the design space of task allocation. This work proposes a thermal optimal task allocation algorithm for multi-core 3D IC with interlayer cooling system, integrated with simulated annealing method. The results show that the maximal temperature and temperature gradient reduced by 19.4 °C and 5.1 °C respectively, compared to the randomized policy, and obtain better balance between normal and extreme cases than traditional ranking policy, in a design of 3 active device layers.
Garbage collection, which entails multiple page copies and a block erase, is a major source of performance fluctuation and degradation for NAND flash memory-based solid-state drives. This work aims to reduce its overhead by generating a skewed distribution of valid pages over all the blocks. Therefore, we propose classifying data as hot, warm, or cold according to their update frequencies, and to cluster them into different blocks. Our performance evaluation shows that the proposed scheme reduces the total garbage-collection count up to 43.4%, compared to the original page-mapping scheme, for an average performance improvement of up to 34.5% without any additional memory overhead.
We present a new simple and low-cost process for fabricating low-loss single-mode fiber (SMF) cladding preforms by a modified slurry casting method, in which the cladding preform and a core rod obtained separately with the VAD method are assembled by a rod-in-tube method. The fabricated SMF showed almost the same loss characteristics as a standard SMF with a minimum loss of 0.19 dB/km at 1550 nm and an OH-free loss spectrum, which were realized with an OH reduction process in a slurry casting based cladding. This OH reduction method plays an important role in preventing OH diffusion into the core and inner cladding.