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101.
Enhancing the performances of recycling folded cascode OpAmp in nanoscale CMOS through voltage supply doubling and design for reliability 下载免费PDF全文
Pui‐In Mak Miao Liu Yaohua Zhao Rui P. Martins 《International Journal of Circuit Theory and Applications》2014,42(6):605-619
Current‐oriented operational amplifier (OpAmp) design has been common for its orderly current‐to‐speed tradeoff. However, for high‐precision or high‐linearity applications, increasing the current does not help much, as the supply voltage (VDD) and intrinsic gain of the MOSFETs in ultra‐scaled CMOS technologies are very limited. This paper introduces voltage‐oriented circuit techniques to address such limitations. Specifically, a 2xVDD‐enabled recycling folded cascade (RFC) OpAmp is proposed. It features: (1) current recycling to enhance the effective trans conductance by 4x with no extra power; (2) transistor stacking to boost the output resistance by one to two orders of magnitude; and (3) VDD elevating to enlarge the linear output swing by 4x. Comparing with its 1xVDD RFC and FC counterparts, the proposed solution achieves 20‐dB higher DC gain (i.e. 72.8 dB) in open loop and 20‐dB lower IM3 (i.e., –76.5 dB) in closed loop, under the same power budget of 0.6 mW in a 1‐V General Purpose 65‐nm CMOS process. In many applications, these joint improvements in a single stage are already adequate, being more power efficient (i.e. less current paths), stable (i.e. more phase margin), and compact (i.e. no frequency compensation) than multi‐stage OpAmps. Voltage‐conscious biasing and node‐voltage trajectory check ensure the device reliability in both transient and steady states. No specialized high‐voltage device is necessary. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Sang Hyun Park Younghwan Jin Kyunghan Ahn In Chung Chung-Yul Yoo 《Journal of Electronic Materials》2017,46(2):848-855
The structural and electrical characteristics of Ag/Ni bilayer metallization on polycrystalline thermoelectric SnSe were investigated. Two difficulties with thermoelectric SnSe metallization were identified for Ag and Ni single layers: Sn diffusion into the Ag metallization layer and unexpected cracks in the Ni metallization layer. The proposed Ag/Ni bilayer was prepared by hot-pressing, demonstrating successful metallization on the SnSe surface without interfacial cracks or elemental penetration into the metallization layer. Structural analysis revealed that the Ni layer reacts with SnSe, forming several crystalline phases during metallization that are beneficial for reducing contact resistance. Detailed investigation of the Ni/SnSe interface layer confirms columnar Ni-Sn intermetallic phases [(Ni3Sn and Ni3Sn2) and Ni5.63SnSe2] that suppress Sn diffusion into the Ag layer. Electrical specific-contact resistivity (5.32 × 10?4 Ω cm2) of the Ag/Ni bilayer requires further modification for development of high-efficiency polycrystalline SnSe thermoelectric modules. 相似文献
104.
Seungwon Park Jaekyeong Yoo Seung Ju Han Ji Hwan Song Eo Jin Lee In Kyu Song 《International Journal of Hydrogen Energy》2017,42(22):15096-15106
A series of mesoporous nickel–boron–alumina xerogel (x-NBA) catalysts with different boron/nickel molar ratio (x = 0–1) were prepared by an epoxide-driven sol–gel method. The effect of boron/nickel molar ratio on the catalytic activities and physicochemical properties of nickel–boron–alumina xerogel catalysts was investigated in the steam reforming of liquefied natural gas (LNG). All the mesoporous x-NBA catalysts showed similar surface area. Introduction of boron increased interaction between nickel and support. In addition, introduction of boron into x-NBA catalysts reduced methane activation energy and increased nickel surface area. Promotion of boron had a positive effect on the catalytic activity due to the increase of adsorbed methane and nickel surface area. The amount of adsorbed methane and nickel surface area exhibited volcano-shaped trends with respect to boron/nickel molar ratio. LNG conversion and hydrogen yield increased with increasing the amount of adsorbed methane and with increasing nickel surface area. Among the catalysts, 0.3-NBA, which retained the largest amount of adsorbed methane and the highest nickel surface area, showed the best catalytic performance. It was also revealed that x-NBA catalysts showed strong coke resistance during the steam reforming reaction. 相似文献
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Multimedia Tools and Applications - SafeGuard is proposed as a solution to monitor behaviors of smartphone applications in real-time and detect and block any malicious behaviors. This solution... 相似文献
107.
Nguyen Hai Duong Na In Seop Kim Soo Hyung Lee Guee Sang Yang Hyung Jeong Choi Jun Ho 《Multimedia Tools and Applications》2019,78(4):4563-4577
Multimedia Tools and Applications - Object tracking, especially human tracking is one of the challenging research problems in computer vision. Although the performance has gained some positive... 相似文献
108.
The electrical resistance of bipolar plates for polymer–electrolyte membrane fuel cells (PEMFCs) should be very low to conduct the electricity generated with minimum electrical loss. The resistance of a bipolar plate consists of the bulk material resistance and the interfacial contact resistance when two such plates are contacted to provide channels for fuel and air (oxygen) supplies. 相似文献
109.
With the recent growth in smartphone services, the “mobile” environment has become a key factor to consider in the design of the future Internet. In this paper, we propose Mobile‐Oriented Future Internet (MOFI), which is a new architecture for the future Internet for mobile‐oriented environments. The MOFI architecture is designed with three functional features: global identifier and local locator in the identifier‐locator separation, query‐first data delivery for route optimization, and distributed control of identifier‐locator mapping. The proposed architecture and functional operations are implemented and tested using the Linux platform. From the experiment results, we see that the MOFI architecture performs better than the existing identifier‐locator separation schemes, such as Proxy Mobile IP and Host Identity Protocol, in terms of data throughout, mapping control overhead, and handover delay. 相似文献
110.